Hello, my name is Sonia Miles. I am an RCVS recognised advanced practitioner in zoological medicine and a WA VMA certified aquatic species vet. I run Highcraft exotic vets, and today I will be taking you through advanced avian medicine.

So to start with, well, obviously we're gonna be going through some more of the advanced avian techniques. So once we are gonna just basically assume that you guys already know how to do the basics, we are going to. Touch on some of the more advanced techniques, but also some of the common scenarios that we will use them in.

So towards the end, we're gonna kind of do a bit of a summary of specific diseases that's gonna be covering a little bit about respiratory medicine, reproductive and some gastrointestinal disease. Yes, I am gonna assume that you guys know, one, how to safely anaesthetize your patient, how and where to take blood samples, and how to perform some of the basic diagnostic tests, like swabs, for example. So first off, we're gonna start with diagnostic sampling.

So, I'm assuming that you guys already know how and where to take your blood samples from. But once you've taken your blood sample, we're gonna need to interpret it. So, starting with haematology, it is an invaluable part of the clinical management of any avian patient case.

Avian erythrocytes and leukocytes can be evaluated with automated or even manual techniques. A pack cell volume, total erythrocy count, haemoglobin concentration, and even reticulocyte counts and erythrocyte morphology. Total white blood cell counts and leukocyte differentials are all gonna be used to evaluate the avian hemogram.

Now it should be noted that although haematological reference ranges are available for many avian species, this is going to be quite variable depending on the age, sex, season, environment, and under hormonal influences. Now the half life of Adan erythrocytes is relatively short, approximately 28 to 45 days, which results in regular appearance of poly polychromatophilic erythrocytes, which we'll approximately see in about 1 to 5% of the total erythrocyte count. Now the circulating blood pool is gonna have these polychromatic erythrocytes.

Now they're gonna be more rounded in appearance. Their cytoplasm is more basophilic staining, and their nuclei are gonna be more rounded with more densely packed chromatin when compared to the mature erythrocytes. They, along with reticulocytes, are indicative of bone marrow activity and erythrocyte regenerative capability in that avian species.

Now reticulocytes are defined as having a distinct ring of reticular material. Immature erythrocytes are basophilic staining with basophilic staining cytoplasm, and they are much smaller and more rounded in appearance to the mature red blood cells. They are an indication of a marked regenerative response in that avian patient.

And a slight synocytosis is thought to be an insignificant finding in birds with a normal RDW percentage of around 10 to 11%. Regenerative anemias are characterised by the presence of polychromatic and polychromasia and reticular cytosis, macrocytosis, and an increased RDW percentage. Acute blood loss is gonna be the most common cause for regenerative anaemia in birds, but we can also have hemolytic anaemia as a result of parasites such as plasmodium.

We can see it with septicemia, acute toxicosis, and even some immune-mediated conditions. Now there's non-regenerative anemias seem to be the most common type of anaemia described in birds, and it's an indicative of a lack of appropriate bone marrow response and is often caused by these chronic diseases, but also toxicosis and some cancers. So a total white blood cell count, an estimated white blood cell count, and leukocyte differentials can be performed again, automated or via manual techniques.

And these are used to evaluate leukocytes in the avian hemogram. A leukocytosis refers to an elevation in the total white blood cell count and is more often associated with an inflammatory disease, maybe degenerative joint disease or infectious disease, but also stress. So it can be a normal finding in young birds as well.

And if there is a leukocytosis of over 30,000, we'll be seeing this with infectious diseases such as lamodophylla, aspergillosis, mycobacteriosis, and even some respiratory disease such as pneumonia or selomitis, salpingitis, and some viral infections. Now stress leukograms have been reported in various different species, such as macaws, African greys and cockatoos, as well as in various other avian species and can occur as a result of just travelling to the vet practise. Leukopenia is often associated with chronic infections or inflammatory diseases.

We can sometimes see it in overwhelming bacterial or viral infections such as circa virus in young birds. Herophils are the most common granulocyte, found in the peripheral blood and is usually the most predominant white blood cell. Avian heteropphils are gonna be eosinophilic, oval, and they have a spindle shaped granules which tend to cover most of the heteropphy's nucleus.

Heterophilia is associated with acute or chronic inflammation, with infectious diseases, stress, and can be normal in some young birds. True heteroppenias are rare, but we could see this again with overwhelming infections. Toxic heterophils are a significant finding on an avian blood smear and can be seen with severe diseases that affect the production and release of the bone marrow.

The toxic heterophils have increased cytoplasmic basophia, vacuation of the cytoplasm and hyper segmentation. Lymphocytes are gonna be your 2nd most common white blood cell in most avian species apart from the Amazonian species where they do tend to be the predominant leukocyte. They are round cells, they have a large nucleus to cytoplasmic ratio.

And a lymphocytosis is pretty uncommon but can occur as a result of an infection or inflammation. A lymphoenia is often as a relative to a significant increase in heterophils or as a result of viral infections. Eosinophils are round cells with pale blue cytoplasm, and that roundness will vary depending on the species.

The granules within are distinctly eosinophilic, hence the name, and they are brighter than those heteropphils that we talked about previously. And he is an affiliate, kind of thinking predominantly parasitic infections, and he, he is an opinion is pretty rare. Basophils are uncommon, but they look exactly like mammal basophils, and they're potentially linked to allergic reactions and sometimes have been seen in chlamydia infections.

And then monocytes are going to be your largest mononuclear leukocyte. They don't seem to be seen particularly very often. They are, have a, they have a round nucleus.

The cytoplasm is blue to grey, and we can often see these in chronic infections such as chlamydia, mycobacteriosis, and some other bacterial granulomatous diseases. And then finally the thrombocytes. These are small dense cells with dense nucleochromatin and clear cytoplasm.

These cells are gonna clump, so counting can be quite challenging, and thrombocytopenia can occur due to bone marrow suppression or disease processes indicative of excessive demand. Now certain viral diseases such as circa virus, rea virus, and polyoma virus can also cause a thrombocytopenia. So now onto biochemistries.

Well, there are gonna be significant differences both interspecies but also intraspecies as well. With respect to the plasma and serum chemistry values. And this can make interpretation pretty difficult.

So most plasma and serum proteins are made by the liver, not the immunoglobulins, obviously. Proteins can help the correct on that help keep correct oncotic pressure, and they will transport various different substances, promote inflammation, and it will complement the cascade. Major proteins include the albumin and globulin, and total protein levels in birds are approximately 50% of that of mammals.

A protein electrophoresis is gonna be the most accurate way of assessing these fractions reliably. You can see abnormal levels due to dehydration, inflammation, but also in hormonal fluctuations, and the presence of abnormal proteins or abnormal protein concentrations as well. So the age of the patient and the stage of that patient's development are going to influence the protein concentrations.

A decrease can be as a result of haemorrhage or protein eluded in enteropathies, nephropathies, or even dermatopathies. If we've got some of these birds with chronic feather plucking, diseases where they've started to damage their skin can be a result of it. Decreased protein synthesis can be caused by liver disease, we have to bear that in mind as well.

And the decrease can be caused by malabsorption or maldigestion. In healthy birds, total body calcium is split between protein bound and ionised. The control of these levels is likely going to be mainly a function of the parathyroid hormone and vitamin D levels in calcitonin.

As opposed to mammals, calcitonin in the net effect is not to decrease calcium but to control hypercalcemia and protect the skeleton for excessive absorption. Hypercalcemia can be seen with hypervitaminosis D or primary hyperparathyroidism, for example, and some neoplasias. You can also see with egg production too, or as a result of homolysis when the blood samples are in transit.

Hypoalbinemia or even hypo hypoparathyroidism may lead to hypocalcemias. Now most cholesterol is synthesised by the liver. Reference ranges are particularly lacking in the vast majority of species, but a range of around 180 to 250 milligrammes per deciliter are accepted for most species.

High levels of cholesterol can be used for endocrine disorders and low levels might result in hepatic from hepatic insufficiencies. Glucose is an essential energy source, and in contrast to mammals, glucagon, not insulin, is the major mediator for carbohydrate metabolism in birds. Hypoglycemia can be seen, as, as a result of diabetes.

It's reported in birds as well, or the release of production of endocrine diseases as well. Hypoglycemic disorders are gonna be resulting in an increase in glucose utilisation or a decrease in glucose production, and we can see this with hepatic insufficiencies. Now disorders that cause elevation in phosphate can be artifactual if we've got hemolysis of our sample, but we can see it with urinary disease as well.

If you've got a hypophosphatemia, well this can result from an a decrease in dietary intake, so an anorexic patient or primary hyperparathyroidism, for example. Now the major end product of protein breakdown is in birds is uric acid. Now this is produced in the liver and eliminated by tubular secretion independent of that patient's hydration status.

So, high levels of uric acid can be an indicator of renal disease in avian patients. Creatinine, usually not really that particularly valuable in birds, to be perfectly honest, when it comes to assessing renal function, but elevations can be seen with selomitis, septicaemia, or even renal trauma as a result of nephrotoxic drugs. And now onto the liver enzymes which can be a little bit more complicated.

So, elevations in ART, well, they can be occurring from, because ART is in very many, many different tissues, and if they're damaged, obviously it's nonspecific. So this does include the liver, the heart, skeletal muscle, lungs, and intestines, which means that, well, if you see an elevation in ALT, you cannot automatically think that it is liver disease. However, in some species, an ALT can also be seen with renal disease as well.

ALP again, can be elevated due to kidney disease, intestinal disease, and with liver disease. So again, non-liver specific. And although this enzyme is active in particularly low levels in the the liver, we often see it as a result of more osteoblastic activity.

So bone growth, osteomyelitis, nutritional secondary hyperparathyroidism, for example. So again, another non-specific enzyme. AST again, found in various tissues, including the liver, heart, and skeletal muscle, brain and kidney.

And significant elevations in this are more likely linked to changes to liver and skeletal muscle, which is why looking at the AST in line with creatinine kinase is really, really helpful. So if creatinine kinase is normal, but we have an elevation in AST, OK, that's pointing more towards liver. GLDH this is gonna be your most specific liver enzyme in birds.

Most specifically for hepatocellular damage or necrosis, but this again, this sensitivity can actually vary differently between species. Bile acids, your breakdown of products of cholesterol, and they're excreted by the biliary system. They act as an emulsifying agent, aiding in the digestion of fats, and bioasses in the intestine are either absorbed by the small intestinal mucosa or enter the portal and enter the porter system, or they are where they are deconjunctiated by the enteric bacteria and again absorbed by the small intestine or are broken down and excreted in the faeces.

Now bile acids that enter the portal system and then cleared by the portal, buzz supply and hepatocytes. So the amount of bile acids that is not removed from the portal system can then be measured, and that is the kind of like the the the bile acids that are circulating in the general circulation. An increased bile acid level is gonna be an indication of impaired hepatic function, and elevations in bile acids appear to be a sensitive indicator of hepatic disease and that reduced hepatic function in bird species.

Bioasses that levels that are lower than expected can indicate cirrhosis of the liver. Creatinine kinase, we touched on this a second ago, is found in skeletal muscle, heart muscle and brain tissue, and increases are associated with muscle cell necrosis, neurological disease, and even vitamin E and selenium deficiencies. One of the times that we see this predominantly is just by taking a blood sample.

Decreases in creatinine kinase can be as a result of bacterial contamination of your blood sample. And then just briefly touching on some of the electrolytes or sodium, it's gonna be your primary extracellular cationon and it's gonna require some knowledge of the patient's hydration status when plasma concentrations are going to be interpreted. Total bloody sodium concentrations and direct control of the kidneys.

So a hyponatremia may result in increased sodium uptake, with increased water loss, decreased water uptake, salt poisoning, for example, if owners are feeding them kind of weird and wonderful foods like chips, for example. Now hyponatremia may result from an increased loss through the gastrointestinal tracts, if you've got a diarrhoea or with renal disease. Now potassium is the major intracellular cation and again requires knowledge and consideration of that patient's acid-based status when you're gonna be interpreting them.

Unfortunately, the clinical significance of acid-based status in companion avian species is really not fully understood. But hyperkalemia can be seen when we've got a metabolic or respiratory acidosis and a hypokalemia can result from a decrease in intake from the diet or an increase in potassium loss through the gastrointestinal tract. So next we've got our traquia wash.

So I would only ever perform a tracheal rush in the anaesthetized patient. We want to be inserting a sterile catheter, either blind or with endoscopic guidance. It can be passed through the glottis.

We've got a picture here of an eagle on the left hand side. You can see the glottis in birds really, really clearly. So you're gonna pass either an endoscope or a sterile catheter through that glottis into the trachea just to the point, cranial to the syrinx, and instil 1 to 2 mL of 1 to 2 mL per kilo of sterile saline and then immediately aspirate it.

Now, once we've got our samples, we want to be sending those off for cytology and culture sensitivity testing. So we're gonna go over this a few times. We want to be putting some samples into, an EDTA tube.

We want to be putting some of the sample into a plain serum tube, making sure that that gets sent off to the lab. But it's always recommended to perform a, fresh smears at exactly the same time as well. Next, we've got our air sac swabs or our air sac washes.

So samples from the lower respiratory tract in cases of air sacculitis, for example, can be obtained with endoscopic and laparoscopic techniques. So the endoscope is gonna allow direct visualisation to the site-specific biopsies and, the internal structures. So, when I'm performing these air sac swabs and washes, I tend to have a bit of a look around as well, and I do go into more specifics on endoscopy a little later.

So that bird should be placed in a lateral recumbency and the area around the last rib aseptically prepared. Sometimes you do a clip, sometimes you can just move those feathers. It depends on the species.

This is a duck here, that's just kind of like positioned in the way that I would normally perform my endoscopic examination. A small incision is then gonna be made caudal to the last rib and cranial to the thigh muscle. The deeper muscles are then gonna be blunt dissected and the thoracic air sac penetrated.

Now the site can be explored with that endoscope like I mentioned, and samples again, taken for cytology and culture sensitivities. So we can make our incision, have a look around with a scope, pop a swab in there and take samples. But if we're gonna be doing an air sac lavage, we want to be instilling about 3 to 5 mL per kilo of sterile saline, injecting that straight into the air sac and then aspirating that immediately.

Now, we, once we obviously in there, we can also take biopsies and sending that off for histopathology and everything as well. So now on to nasal flushing. So nasal flushing can be used diagnostically to collect fluid samples if we've got nasal discharge, but also sometimes solid debris as well as foreign bodies.

And we do have to bear in mind that we might have oral contamination with this. So to avoid this and help with the interpretation of cultural sensitivity results, I tend to recommend taking a, loanal cleft swab as well, that's gonna help with the differentiation between the two areas. Now nasal flushing, I personally perform under general anaesthesia, but it has been reported in the conscious patient.

And patients should be held downwards with 3 to 10 mL of warm saline, syringed into the nares with the syringe kind of pressed right up against it to form a seal. Now each nare should be flushed with equal amounts and samples taken as they drip out of the mouth. They should again be sent for culture sensitivity testing using a plain serum tube, as well as EDTA tubes, that are gonna allow for your, your, your cytological examinations and making your smears.

OK, so sinus aspiration. Well, birds have this pre-orbital diverticulum, and this can be assessed by needle penetration through the skin just cordal to the oral beak commissioner. Ventral to the zygomatic bone and directed towards the point midway between the eye and the nose.

The suborbital chamber and the infraorbital diverticulum are approached by the insertion of the needle perpendicular to the xyus and ventral to the eye, either ventral to the dorsal oh, for God's sake. Sorry. I'm turning my phone off as well and now work phoning me, just go away and leave me alone.

Don't worry, just take your time, So you, it's fine. OK. So sinus aspiration is really useful for sampling fluids caused by sinusitis, and we obviously want to be basing this on previous imaging.

We want to be using a 22 to 25 gauge needle and a 3 to 12 mil syringe and performing it under general anaesthesia. We want to be aseptically preparing the sites, and we can do this by entering the preorbital diverticulum, by needle penetration through the skin just according to the oral commissioner, ventral to the zygomatic bone and directed towards the point midway between the eye and the nares. The suborbital chamber and infraorbital diverticulum are approached by insertion of the needle perpendicular to the sinus, ventral to the eye, and either ventral or dorsal to the zygomatic eye.

And we want to be monitoring the eye for slight movements that might suggest that we might be a little bit close to penetrating the eye and redirect that needle as needed. And we want to be taking samples of cultural sensitivity testing and cytological examination. Now, it can help by opening the beak.

And again, when we're taking our cytological and culture sensitivity samples, we're gonna be placing them into a plain EDTA tube and a plain serum tube, and we want to be taking, making fresh smears and sending those off to an appropriate lab. Next, we've got our crop wash. So this can be indicated in birds that have got any sort of crop pathology.

We want to be performing this in the anaesthetized patients, but we can do it in an appropriately restrained bird as well, especially if the bird is maybe unfortunately too sick, to be anaesthetized. So if we're doing an anaesthetized patient, we want to be securing that airway, just to make sure that we're avoiding any risk of, of aspiration. We want to be holding the head up and holding the mouth open and carefully passing a soft plastic tube, or, I use a thin metal garbage tube as well.

We want to be extending that bird's neck to straighten that oesophagus to minimise the risk of any sort of potential, perforation of that esophageal wall. And then we want to be infusing 10 to 20 mL per kg of warm saline solution into that crop, massaging it to increase that cellular recovery, and then aspirating that fluid again. Now samples again can be taken for cytological and culture sensitivity testing, you see a little bit of a pattern here, making sure that we plug it into a plane and an EDTA tube and taking fresh smears.

Now, the normal cytology of the oral cavity, oesophagus, and crop in cytosine birds is gonna include moderate levels of gramme positive bacteria and very few to rare gram-negative bacteria. You can also concentrate your samples by centrifuging your washes and examining them while you're making the smears. And then we have sallomacentesis.

So indications for this include ascites, if you're suspicious of a peritonitis or selomitis, worried about hema peritoneum or sort of any other fluid accumulation in birds. Now many of these birds often present as dysneic, so that means that we need to be handling them with care, warning our owners that unfortunately, just handling a dyspneic bird can result in death. And this is often as a result of compression of those air sacs, which are obviously part of the the normal respiratory system in birds.

So, normal abdominal fluids, they always have a little bit of fluid moving around in there. So that's not the type of fluid that we're worried about. We're talking about excessive amounts of fluid.

Normally a little bit wet in there if you're looking around with your endoscope, and that just helps lubricate and move the organs around. But when we're talking about a proper effusion, well, obviously we've got our transiates, we've got our modified transiates, and we've got our exudates. So, pure transitates, well, they're going to result from changes of oncotic pressure associated with maybe hypoprotemias, potentially cardiac or liver disease, and they're going to be characterised by being of low cellularity.

They have specific gravities of 1020 or less, and total proteins of 3 grammes per deciliter or less. They tend to be clear to pale yellow colour. Modified transudates have an increased cellularity, so total cell cancer tend to be greater than 1000, less than 5000, and they tend to involve mononuclear sites, granulocytes, and sometimes some reactive mesothelial cells.

And to date, they tend to typically have high cellularity, so this is greater than the 5000. They have a high specific gra gravity, tend to be higher than 1020, and protein levels greater than 3 grammes per deciliter. Now the prominent predominant cell type of these exudates is going to indicate the source of where that exudate is potentially coming from or why that's forming to start with.

So whether we've got a septic exudate, for example. Now performing these, we want to be doing it midline. So your ventral mid abdomen is gonna be aseptically repaired.

You're going to be using a small gauge needle, normally around about 21 to 27 gauge depending on the size of the bird that you've got. And we're gonna be inserting that. Midline just quarter to the keel, and this is going to try and avoid the internal organs like the gizzard, for example.

That needle is then gonna be directed to the side of the body wall, and that fluid is going to be aspirated. Now, same with all of the other fluids that we talked about previously, we want to be sending that off the cytological examination and culture and sensitivity testing. And there's something a little bit more niche, admittedly, I've only ever performed this once before, but it is reported in the literature that we can perform cerebrospinal fluid taps.

Now, the avian cerebrospinal fluid analysis, we tend to consider doing this. Oh, this is a last ditch attempt, because nobody wants to be sticking a needle in the back of the head of a bird. But we can be doing it if we've got a neurological disease, if we're worried about infectious or inflammatory, or even some neoplastic disorders of the central nervous system.

Now, if done correctly, if done correctly, it does cause very, very little issue. But the lack of quad quina and the presence of the sinsacrum in birds means that a lumbar cerebrospinal fluid is a tap is not going to be possible. Therefore, you are aiming for that foramen magnum as a site of intent.

Now, that means sticking a needle in the back of the bird's head. Obviously, obviously it goes without saying that we're gonna be doing this, performing it under general anaesthesia. So in birds, the cerebrospinal fluid is collected from the 4th ventricle the subarachnoid space between the dorsal surface of the ella oblongata and the cerebellum.

Now although limited by the low fluid volume, total cell counts, cytology, total protein evaluation, and microbiology are all potentially performed from this. Now, admittedly, I have used a picture of a tiny little bird. On the left hand side, I did not perform a cerebrospinal fluid tap in this bird, it was far too small, but it just kind of like giving you the idea that if we've got a bird with a head tilt, that is something that you could consider doing.

The that patient is anaesthetized, placed in lateral recumbency, and the caudal dorsal skull is aseptically repaired. The Atlanto-occipital joint is flexed at a 30 degree angle, and an appropriately sized hypodermic needle is placed dorsal midline just cordal to the occipital protrudance at a 45 degree angle. So the horizontal axis of the head, and that needle is going to be slowly advanced rotally.

I mean, I'm talking about 1 millimetre intervals until resistance is found, and then you can aspirate 1 mL of cerebrospinal fluid per 5 kg of body weight. So now we're gonna start talking about our diagnostic imaging. So again, I'm going to assume that you guys know kind of like your basic plain radiography.

So we're just going to be touching on that very, very briefly. So obviously, there are various different imaging techniques that can be employed in general practise. Now, the most common, radiography.

So as I mentioned, we've got a plain radiography, I'm gonna assume that you guys know how to do that. But contrast radiography, as we can see in this picture on the right hand side here is really, really helpful, specifically when we're looking at gastrointestinal disease. Now contrast studies of the upper and lower gastrointestinal tracts are often indicated based on suspicion of things like space occupying lesions, for example, if we're worried about ulceration of the gastrointestinal tract, abnormalities of different sizes of the gastrointestinal tract, or even gastric foreign bodies as well.

Now there's two types of contrast that we can use, barium, approximately 25 mL per kg can be given by garage tube into the crop, we've got Ihexo as well, given at 240 milligrammes of iodine per mL, and we tend to dilute this one on one with tap water before we use it. Now the use of IEexo is gonna result in significantly decreased gastrointestinal time in comparison to barium. So with variant It takes approximately 3 hours to work its way through the gastrointestinal tract, the Ihexo about 1 hour.

So if you're using barium, the recommendations are to take films at 5, 30, 60, 90, 120, and 180 minutes post administration. Obviously that's a lot of anaesthetics. Slightly different schedule for the IHECO, that's gonna be 13, 1530, 60, and possibly 120 minutes are recommended.

The IHO is also eliminating the concern of contrast medium residue, so endoscopy and surgery can be performed afterwards with no worry that that's going to be contaminating the area. Or if you're worried about a perforation, I would go for the IHEexo as well. We've then got CT scanning and MRI scanning.

Now these tend to only be available at referral level centres. CT scans, they're obviously gonna provide you with cross-sectional imaging, and that's gonna be much more sensitive than the radiographs. It's gonna pick up much more intricate details as well.

Now this cross-sectional image is gonna eliminate the overlying structures and help with your interpretation. CT is gonna be best for evaluating bone and air filled structures, with a soft tissue resolation being inferior to MRI. But unfortunately, MRI does tend to be cost prohibitive in the vast majority of cases.

But it is better for your soft tissue structures, especially your central nervous system, your salamic cavities and your upper respiratory tract as well. So MRI studies, they do take longer to perform than CT scans as well, so you do have to bear that in mind when you're thinking about your anaesthetic risks. We then got ultrasound.

Now, due to the presence of the air sacs in birds, and we already know that the air and ultrasound don't really mix, and often the small size of many of our avian patients can be quite limited in comparison to our mammalian species. But there are 3 acoustic windows that you can use if you've got an avian patient that is big enough. First, you've got the cranial ventral approach on the midline caudal to the sternum.

Second, you've got the caudal ventral approach between the pubic bones, and thirdly, you've got your lateral approach. So this is the flank area directly behind that last rib on each side, kind of where we touched on, doing our air sac washes and endoscopy, which again, we'll get to in a second. That this is gonna, your approach to your ultrasound is really going to depend on, one, the size of your patient, but also the size of the transducers that you've got available.

I'm very spoiled. I've got a tiny, tiny little hockey stick probe, which is absolutely fantastic for most of our species, but I do appreciate if you're in a first opinion practise, you tend to have to kind of use your cat dog probes as well, which, unfortunately may not work particularly very well. Now we want to be fasting our patients normally around a couple of hours in let's say an African grey, for example.

We can apply acoustic coupling gel to the skin. I will probably be minimising, the amount of surgical spirit that you use just because these guys can become hypothermic really, really easily. And you can assess quite a lot of the organs, you can assess the heart, the liver, gonads, etc.

I find this really, really useful in chickens, really, really useful in chickens, especially when we're worried about our reproductive diseases. So I tend to go for ultrasonography, when I have those cases presented to me. And then we have fluoroscopy.

So I do appreciate again this does tend to be a referral level diagnostic facility. However, it is brilliant, it it is really, really good and it could be considered as an adjunct to radiography or CT scanning. It doesn't provide as much detail as radiography, but it does allow motion to be seen.

And in certain circumstances, which we will get onto a little later when we touch on proventricular dilatation disease, is so helpful. And the motion itself is actually easier for the brain to detect and then interpret. So actually your brain works better seeing the mobility that the fluoroscopy allows you to see.

Now, in contrast to radiography, denser objects are black, so obviously, opposite of radiographs. Now one of the main downsides, it's expensive, it's really, really expensive, to obviously set it up and that you're not just going to be needing the imaging heads, but also a way of recording those images and the ability to access those images. So a pack system, for example, to actually be able to read them.

Main upside is that we can do this in a completely conscious patient. Now I've done a lot of these when I've been suspicious of proventricular disease, I've just got the birds to sit on a perch, dim the lights, and it works, fantastically, especially as well if you've maybe got a secondary, effusion, for example, and that means that your, your, radiography, you just can't see anything because it's whited it out. The, you're gonna be doing.

Minimal handling because these patients are going to be inevitably dysnes, that's only added bonus. And yeah, if you're doing it consciously, dim the lights in whatever room that you're, that you're using it. And for those of you that don't have fluoroscopy, bear in mind that a lot of referral centres, such as Highcroft, we do have access to this.

So this may become a possibility from a referral level point of view if you don't have it yourself. Now, this is excellent for gastric studies, specifically looking for your metallic foreign bodies, for example, but you're also, if you're considering doing contrast radiography, this is going to be really, really helpful in you determining when your contrast is. Actually at the point that you want it to be.

So I know we, we've literally just touched on your contrast radiography and doing X amount of radiographs. Well, actually, this will minimise the amount of times that you need to do repeat GAs and positioning and therefore decrease the risk for your patient as well. And because, obviously, gastrointestinal, because general anaesthetics are not needed, you can also be giving them food items during the fluoroscopy as well.

And actually watching for functional deficits within the gastrointestinal tract. So, like I've already said, fluoroscopy for me is really, really helpful with the diagnosis of proventricular dilation disease, which we will get to in a second. Now endoscopy.

So there's gonna be various different systems that you can employ. Again, I'm pretty spoiled. I've got flexible endoscopy, I've got various different sizes of rigid endoscopy with various different degrees of of telescope.

But if you need just one, or you can only afford just one, you're only allowed to buy just one. I would strongly recommend the 2.7 millimetre telescope, the operating sheath, 2.7 millimetre telescope at the 30 degree angle one is going to be your most versatile, and the various rays of, of, of forceps of your biopsy and grasping forceps, they're probably the two that I use the most.

Now, this is going to allow laparoscopic approaches to diagnostic sampling. Gone are the days where we need to be performing exploratory surgeries. We can actually do this all via endoscopy.

So it, it also really does, minimise the, the risks associated with the anaesthesia and the surgeries themselves, but also much, much faster. And actually I find that I can convince a lot more owners to do things and, and biopsy things endoscopically than, performing, open synomic surgeries. Now it goes without saying, as with any surgery, we want to be making sure our patient is as stabilised as possible prior to the surgery.

And we want to be making sure that they are fasted. So I just wanted to touch briefly on some just some rough timings of how long we want fast our patients beforehand. But essentially, the smaller the bird, the shorter the fasting.

Raptors are going to be the ones that you can actually fast the longest. I tend to not get the owners to do this. I tend to do this myself and just schedule my day around the fasting.

So, again, the smaller the bird, the shorter the fasting time, the larger the bird, the longer the fasting time. Now, because birds are also incredibly delicate, endoscopy can sometimes require two people to help. I, I can manage to do it a lot, and I guess that's because I've, I've become very, practised in kind of doing multiple things with different fingers on one hand, for example.

But you do, as a, as a standard, and this is one thing that, Steve's divers taught me when we were doing his endoscopic CPD. Is that always control the base of your telescope, the eyepiece, and the camera with your dominant hand. So for me, that's my right hand with the terminal end, so the end of it held by your inferior hand.

Sometimes you just need an extra pair of hands. So sometimes you just can't do it all at one by yourself. So what I'll do is get a nurse, for example, or sometimes a vet student.

To actually do the biopsying for me obviously under strict guidance. So I'll be holding the telescope in place, and they'll be doing the biopsy forceps for me and and taking those samples. It just minimises the amount of trauma that we might rogenically cause to that bird during that procedure.

So next, I wanted to briefly touch on some of the areas that we can actually be performing our endoscopy. So starting with tracheoscopy, this is gonna be one of the most straightforward ones. Obviously our bird is anaesthetized and we want a surgical plane to stop them from one biting down on your telescope, because it genuinely will make you cry if they break it.

But also to stop, traumatising themselves, the last thing that we want to do is be scoping the trachea and actually cause a tracheal stricture because we've been too rough. We want our patient anaesthetized, surgical plane and have them placed in dorsal or ventral recumbency with the head and neck extended. Now, in a lot of birds, actually, I tend to do this unsheathed purely because, the telescope and the sheath just doesn't fit down a lot of tracheas.

So, again, because it's unsheathed, we want to be protecting our equipment, and depending on the size of birds, you can mostly get either a 1.9 or a 2.7 millimetre telescope down there.

You can still take your biopsies and you can still take your samples by actually inserting the forceps alongside that telescope. You don't actually have to just poke them down the the operating sheath. If you haven't got it, you can actually use them side by side.

But we do want to be really, really careful not to damage the bird, but also not to damage our equipment. Now we can be assessing the all the way down to the the Sire sometimes in the bigger birds we can actually go a little bit further and find our proximal primary bonky as well. But sometimes the Shaquille diameter really does limit how far we can go, and that is really going to depend on the size of the bird.

The main reason that we'll probably be going down here is if we're suspicious of an aspergilloma. Now, obviously, I've just told you we're shoving a a gently shoving a endoscope down the trachea of a bird, and I've told you that it needs to be anaesthetized. So this is the reason why a little later on, I'll be taking you through air sac placement, air sac tube placement so we can keep that patient anaesthetized and completely bypass the trachea because we're canulating the air sac.

So we will get to that a little while later. Next, we have luoscopy and gastroscopy. This is actually what I was doing in this duck here.

I was using a flexible endoscope to retrieve a little plastic soldier that they that they can eaten. So we can actually examine, while, while we're putting our scope into the mouth, really take advantage of assessing the whole mouth completely as well, and, and looking up inside that cloa. We can assess the oesophagus, crop proventriculous and ventriculous in most birds, round about the 400 to 500 gramme mark.

Using our, 2.7 millimetre rigid endoscope with that 4.8 millimetre operating sheath via that oral approach.

However, in larger birds, we may need to use the flex flexible endoscope, which obviously you can, you can see here. But also, you can sometimes perform a temporaryingluviotomy. So actually insert the scope through the side of the neck into the crop and down that way, that kind of bypasses a good couple of inches of the neck.

Now, gas insulation works well, but personally I tend to use warm saline irrigation. And that is gonna be giving us better mucosal detail, but because of that, we want to be securing our airway and making sure that we don't have any risk of aspiration. We then got colonoscopy, so, putting the camera at the back end of the bird.

Again, we want to be using a warm saline irrigation in that instance, it's gonna give you really, really good mucosal detail. And the specific reasons that we might be doing this, well, called papilloma in our Amazon species, you can also be assessing the coproderm, the Euroderm, the birth of Fabricius in some instances, and also the Proctoderm as well. Now, patient can be anaesthetized, or should be, in my opinion, anaesthetized for this because looking at the literature, there's actually reports of excessive cloacal fluid administration, resulting in oral regurgitation.

So we want to be making sure that one, we're not irrigating too much. But also that we're securing that airway, which personally speaking, if you've got an anaesthetized bird anyway, you should be securing the airway regardless, so you can actually appropriately ventilate your patient. But just in this instance, it has been reported that yes, excessive fluid administration has caused oral regurgitation.

And then we've got our ceoscopy. So this is gonna be by far one of the main reasons that we're gonna be doing this. And there are various different approaches, which is gonna depend on the size of your patient, your target organ, which hopefully you'll have figured out beforehand during the advanced imaging that we've talked about previously, but also, it's gonna depend on whether or not we've got a fusion or not, which I'll get to in a little second.

So starting with your left lateral approach, personally, I think this is probably the most common approach that that I do. Bird is gonna be positioned in right lateral recumbency with the wing secured and the left limb pulled back and out of the way. The entry site is located immediately behind the last rib, just ventral to the lexochialis mediaalis muscle as it courses from the caudal stihom to the is.

Now you can pluck a few feathers in that area, you can tape them out of the way and aseptically prepare that area, incise the skin, 15 blades, absolutely fine. And with a pair of straight hemostats, literally just push through that muscle and you will go straight into, straight into the air sacs. Now we want to be pushing through in a cranial dorsal direction.

You can then replace those forceps with the telescope and have a real good look around. This is also the site of air sat cannulation, which again we will get to in a second, but you can place that with endoscopic guidance as well, a really, really good way of one practising your left salamic approach from an endoscopy point of view. But also it just allows you to have a good look around before you place that air sac tube.

Now what you can do when your telescope is in there, you can actually push up gently against the membranes. They should be glistening and transparent. So you can actually see through them, see the internal structures, but actually small holes in those air sacs will actually repair themselves within 5 to 10 days.

So actually you can push through those air sacs and take your samples as well of various different organs that again, we'll have hopefully figured out where we need to go based on our previous diagnostics. And you don't actually need to close those holes afterwards, as long as they are small, they will literally heal in 5 to 10 days, just literally just a a simple simple suture just involving the skin and the underlying muscles and enough to close it once you've finished. Your right lateral slalomic approach, well, it's like the left lateral, but on the other side, so don't really need to explain that one.

But your ventral approach. This is gonna be the one that you're gonna need to really consider doing when you've got an effusion. So if we had an effusion and we did either the left or the right lateral approach, we would allow fluid to get into the air sacs and we would inadvertently drown our patient.

So we don't want to do that. We're gonna do the ventral approach, the bird is gonna be placed in dorsal recumbency, and we want to go ventral midline in and around the area that we actually mentioned previously about that salomacentesis, aseptically preparing the area, etc. Before we, insert our telescope through.

Now this is a place that, I probably do the vast majority of, of my quick liver biopsies. And in the literature as well, you've also got the clavicular approach. So pretty rare to do this, to be perfectly honest, it's quite scary because there's some pretty big, brachycephalic branches of major blood vessels in this area.

So you want to be very, very careful of those. And we tend to only really use this approach if we're going for, looking at the syringeal region, the heart, and the great vessels. But it really can help with the identification and sampling of maybe if we've got a cranial salamic mass.

So I'm gonna touch on very, very briefly about emergency medicine. So we're gonna touch on ASA tube placement, a little bit about blood transfusions, but also placing a pharyngostomy tube, because these are actually. I I think I was very daunted at doing them to start with, but they're actually very, very straightforward things to do.

So, our air sat tube, and then thank you very much for, Chrissie Green for, giving me the, the pictures of one of her air sat tube placements, for this webinar, mainly because I'm in so, so much of a rush to place an air sat cannula normally because the time is often of the essence that I always forget to take pictures. So thank you very much for allowing me to use this. .

Because bird air sacs, they connect directly to the bronchi. They actually make it, they're the reason why avian respiratory or respiration is so efficient, because they've got that conscious, allowing for that constant gaseous exchange across that air capillary system. We can use it for oxygenation, anaesthesia, obviously, we briefly touched on tracheoscopy.

We want to be placing an air sac cannula for this to actually keep your bird asleep when you're doing it. If we're performing surgeries around the head and neck, so I'm placing this if I need to perform a a tracheotomy or a tracheectomy, . But one of the most kind of main reasons that we tend to, to, to use this is actually if we have an a tracheal obstruction, and this is why I never take pictures because these are the predominant cases that we, we tend to use them in is that you, that bird is dying, if you do not get that air sac cannula in, they cannot oxygenate themselves, they are imminently about to die.

So this is a procedure that you need to be here very quick at doing. Now, it is, it is daunting, but in some instances, unfortunately, needs must. So I think the first time I ever placed an air sac cannula was when I had a full tracheal obstruction and and this bird was fading in front of me, but it resulted in us being able to diagnose it, removed the humongous aspergilloma, its syrinx on the appropriate medication, and actually it did really well.

So yes, there are various uses and they can be actually pretty easily obtained, to be perfectly honest. You can use a cut down and tube here, you can even use IV, tubing, so, your, Your fluid lines, you can actually make an air sac cannula using kind of like an intravenous fluid line as well and they actually they do sell specific air sac cannulas. They should be in 4 days is really the, the ideal length of time, but they can be placed up to 7 days.

But the longer that they are in there, the more likely they are to have secondary bacterial or fungal infections, result in actually an air sacculitis by just placing it. But also, you can potentially cause rogenic trauma to the air sacs, if that air sac is an air sac cannula has maybe been pushed in a little bit too far. We want to be, ideally beforehand, but not always possible, ensuring that we're placing that air sat cannula into a healthy air sac.

So your X-rays and advanced imaging that we've touched on previously can help you determine that. And you really do need minimal equipment. So you really only need a 15 blades, pair of straight hemostats, fine scissors, and suture material.

So I tend to prefer, monofilament and then obviously needle holders, to, to actually, hold your suture material as well, just to make your life a little bit easier. And as I've already touched on, that they're really easy to obtain, either a cut down and qui tube, old, using your, intravenous fluid lines, not old, brand new, using your intravenous fluid lines and cutting that down. We tend to do that quite a lot actually.

Have the sutures replaced and just have that sterilised ready so we've got that to be used in an emergency. You can actually use air sac cannuism and and buy them, that are designed specifically for this case. The birds should be anaesthetized, placed in lateral recumbency.

I tend to place them in right lateral recumbency and insert this on the left hand side. It's just a habit, but obviously, based that on your advanced imaging that you'll have done already. Pluck a small amount of feathers in that area, just call to that that last rib and aseptically prepare it.

Again, that entry site is the junction of the caudal edge of the last rib and that flexicuralis mediais muscle. The pubic bone, in addition, is an additional landmark, and that kind of outlines a triangular shaped region for that region for that cannula placement. Now once the skin is clean, we want to cut it, push our straight hemostats through right into that, underlying air sac.

So through the muscle into that underlying air sac. We then want to open up our hemostats and place the tube between them. So this is where I have a quick look around with my scope as well and take any sort of samples, any sort of air sac washes that we've talked about previously prior to taking that tube, if we, if we need to, allows you to have a a really there's, well, there's there's no .

Way of actually getting an idea about air saps other than the endoscopy. So make the most of that if you've got your scope to hand. We then want to, suture our tube in place, and this can either be, as you can see in this picture, just wrapped around the tube and then a couple of skin sutures placed, just to close that deficit as well.

And actually, it's also really advisable that once you've removed that tube, you want to culture it as well, which is a good practise to get into in case you've got any kind of like problems afterwards. And then to blood transfusions. So traumatic episodes are gonna be the most common reason for significant blood loss in birds.

Now this can be, as a result of I see a lot of owners that have left their birds unattended to cats and dogs, for example, but also damage of blood feathers. Now, birds, they tend to have a blood volume roughly between 4 and 8% of their body weight, meaning that blood loss, especially in the tiny birds, is really significant and a matter of urgency. So no matter what, these are cases that you need to get in ASAP and stabilise as quickly and efficiently as possible.

Birds are able to tolerate acute blood loss much better than mammals of a similar size, and this is because they're able to quickly mobilise immature red blood cells that we mentioned previously from that bone marrow, but they can also swiftly draw fluid from their extravascular spaces. Now personally, how are you gonna know that a bird is gonna need a blood transfusion unless you're gonna be assessing their PCB? So for most species, there should be around 35 to 55%.

If it is less than 15 to 20% in your bird, they're the ones that we're gonna be thinking, right, we potentially need to perform a blood transfusion. Blood groups are actually relatively unknown. They've actually been studied in some species, that includes chickens as well.

But it is general consensus that in an ideal world, we would take a blood sample from a donor of the same species and immediately put that into the, the recipient. But you can probably get away with taking a blood sample from ideally a closely related species. And do that once fine without any issues.

So ideally from the same species, but you'd probably be absolutely fine with taking it from a very similar species or another bird at least once. When we're performing our blood transfusion, obviously from the same species, the red blood cells do tend to last longer, but when we're actually giving the transfusions, we want to do this at a rate of 10 to 20 mL per kilo, given slowly over 10 minutes by bolus injection. Now that patient should be closely monitored during that transfusion for side effects.

Hypothermia or uharia are gonna be the main ones that we may see. Sometimes sudden death is a symptom as well, so we do have to make sure that we're making our owner aware of this, but it is very much a do or die situation. And once they have had their transfusion, we want to be making sure that we're monitoring that patient's PCB afterwards.

It's also advisable to be taking that sample from the recipient birds. We want to be putting it in either sodium citrate, heparin, or even a acid citric dextrose solution as an anticoagulant, using a blood philtre and injecting that immediately into the recipient. And then finally, I just wanted to touch on, esophagostomy tube placement.

So actually, this is really a really straightforward procedure to, to do. We tend to perform it a lot in our mammalian species, I perform a lot in tortoises and my reptile species as well. But it is really, really useful in birds too, and I do it a lot in my raptor species, specifically, or birds that really, really aren't tolerating handling very much.

Now, why might we do this? Well, there are several reasons. Essentially, anything going on with the head that is preventing them from swallowing makes sense.

So, neoplasia in the mouth, crop trauma, if we've got any sort of disease from kind of like the throat upwards, then that's when we're gonna be wanting to perform it. But also in a bird that just really isn't tolerating being hand on a regular basis, especially these kind of long term hospitalised patients. Really straightforward procedure to perform.

We want to make sure that the overlying skin, I do the right hand side of the neck, mid cervical region is plucked and aseptically prepared. We're gonna be wanting to insert a suitably sized curved set of hemostats gently into the oropharynx along the right hand side of the neck. I in hetero, we can actually obviously see the jugular, which that pitch that we had on the previous slide, and you can see the jugular really, really nicely.

Don't cut into it when you're putting your esophagostomy tube in. It's obviously, it's obviously there, so you can actually move it to one side because it's very, very mobile. We then want to find that avascular area of the skin, push up our curved hemostats and incise over the top using a 15 blade.

The jaws of that hemostat can then be pushed through. They can grab that terminal end of the tube which you should have pre-measured before placing it. So, normally want that pre-measured probably about 1/3 of the total length of the bird, make a little mark on it so you know how far you need to pull that through.

So you've grasped your terminal ends, pull that out of the bird's mouth, push the end back down, down the oesophagus, and sometimes you can just give a little tug of the tube at the level of the level of the skin, just to help that flip round. And You want to be pulling that so it's pre-made and pre-measured mark. Now sometimes you're gonna need to manipulate that a little bit, if you're wanting it to deliberately enter the proventriculous then you wanna keep pushing until you find, feel a little bit of resistance and then withdraw it ever so slightly so it's not pushed up against the end of it.

We want to be then making sure that that is in place. So before we start suturing it, do a quick radiograph, you'll be able to see that that's in place, appropriately. Suture that in place, Chinese finger trap or butterfly suture, butterfly dressing in simple interrupted suture works really, really well.

And in some cases we might need to place a little buster collar to stop them interfering with it. When we're using the tube, we wanna make sure that we are flushing it before and after, and we want to be feeding them with 3 to 5% body weight in volume of food. I really, really like the MRA, that works really, really well.

We want to be monitoring it closely for patency and subsequent sight issues and make sure you're keeping a really close eye on the neck. And we want to be removing that tube as quickly as possible, but it can actually be in there for, for weeks at a time. And when you remove it, literally snip your sutures, pull that tube, and that area is gonna heal by second intention.

So finally, I've got some examples of some specific diseases. So we're gonna go through respiratory disease, we're gonna go through reproductive disease and proventricular dilation disease as well before finally touching on, postmortems. And just specifically using this as a, as a summary.

I'm, I'm not gonna go into the specifics of respiratory disease because the, that's a webinar all in itself to be brutally honest. But we're gonna go through kind of, OK, well, these are the these are the tests that I would use in respiratory diseases and just briefly summarise everything that we have just been through. So, respiratory disease.

So, again, being an advanced avian medicine, I'm gonna assume that you know how to perform your clinical examination, what questions that you're gonna need to be asking, how to stabilise your dyspneic patient in a kind of like the standard ways by putting it in a warm oxygenated area. I'm making sure that you know that any bird in respiratory distress handling it could be sadly fatal, which is gonna mean that swift stabilisation with minimal handling and swift diagnosis is gonna be the key to a successful outcome. Now, we have touched on various different ways in it, my opinion of the more advanced diagnostics to help you determine your differential diagnosis.

So again, these following slides are just gonna be a kind of like a summary of that thing. So, The worst case scenario, in my opinion, is a tracheal obstruction. And that's a worst case scenario because that bird is gonna die quickly if you do not get in your air sac cannula.

So we've already mentioned, this is going to basically allow your patient to receive oxygen whilst you're trying to figure out what on earth is going on with it, to start with. One of the most common reasons, aspergilloma at the level of the syrinx or somewhere in the upper respiratory tract that is blocking it. During this time as well, obviously we can perform endoscopy.

We're gonna be using the unsheathed 1.9 2 2.7 millimetre tube.

Using our biopsy forceps alongside that as well to remove aspergilloma. It's a fairly straightforward thing to do. But again, protect your patient, Go gentle.

We do not want to be damaging that tracheal mucosa, but also protect your equipment as well. It's, it's very expensive. We want to be making sure that we have a surgical plane of anaesthesia, so we're not coughing, and that there's damaging its own trachea with you handling the scope and it's not biting down on your telescope.

Now, obviously, once we've stabilised our patient, we're gonna be wanting to perform imaging. So we've got our radiography, we've got a CT scanner, we've got an MRI scanner. That is, again, gonna help you pinpoint your point of entry if we're gonna do any more endoscopy.

Because of the pattern of the flow through the bird's respiratory system, most aspirated material is gonna end up in the cordal thoracic or the abdominal air sacs. So these are going to be places where aspergillosis spores, for example, will be settling. Now these air sacs.

That mean that we are gonna be performing our our left lateral or right lateral solomic approaches. Now, again, because our air sacs are also linked to our bones, in some instances, you have to bear in mind that sometimes respiratory disease can actually be leading to, orthopaedic disease as well, and that's one thing that actually our radiographs can be really, really helpful in picking up too. And I cannot stress enough that if you have suspicion of an effusion, you really need to approach that salamic cavity from that ventral approach.

Effusions, if they're occurring, we're gonna compress our air seps and present as respiratory disease. So it's really, really important to remember that, one, we've got a dysneic patient, handling is a is a minimum, but you need to work out really, really quickly whether this is primary respiratory or secondary respiratory. Is this an actual respiratory tract problem, or does it have a st in a fusion that's compressed its air sacs and it just looks like it's a respiratory problem?

What we can also be doing if we are doing our left lateral salamic approach for our endoscopy, while we're in there, we're taking those air sac washes that we talked about previously, making sure that we're putting samples in plain serum tubes, ETTA tubes and taking fresh smears of the samples that we're taking as well. If we're taking samples for histopathology, we want to be making sure that one, we're protecting those samples, you can get those tiny little cassettes that you can put inside your formalin, so actually it makes the lab's life a hell of a lot easier. But we're using an appropriate formalin to tissue ratio of 1 to 10.

When we have upper respiratory tract disease, nasal flushing can be considered again. I, I only tend to do this in the, the anaesthetized, patient, and we've obviously gone through all the reasons why. We can perform in our tracheal washes at the same time, and again, I tend to do this with endoscopic guidance, so I can actually have a good look at the mucosal detail and take targeted samples.

And we want to be sending them all off for culture sensitivity testing, cytology and histopathology. We wanna be, if we've got up a respiratory tract disease, we also have to bear in mind that that can come hand in hand with with sinus disease as well. And with sinusitis, we can often get this infraorbital sinus swelling.

Often see this in, African greys, this one here actually on the right hand side, had a lot of nasal discharge. We performed a nasal flush, but unfortunately, what hasn't shown up, particularly very well, is this kind of fluctuent swelling on the side of the head that was protruding between the beak and the medial campus of the eye. So this distension, we can get this for various reasons, kind of squamous cell metaplasia as a result of hypervitaminosis.

A and kind of like blocking of all the, the kind of the, the sinuses and everything that are that are in there, but it can also be infectious or neoplastic and granulomatous in in in nature as well. Now. We can take samples consciously, but again, like I mentioned previously, I would really wouldn't advise this, especially because we're gonna be sticking a needle in between the eye and the nose, and I don't want to stab the eye, so I tend to do this in my anaesthetized patient.

And you can enter that sinus with a needle just ventral to the zygomatic arch midway between the sagittal plane of the, formed by the medial commission of the eye and the sagittal plane formed by the net. That needle is directed rostrally towards the beak through the skin at a shallow angle, or pushed immediately at a 90 degree angle to the skin. We want to do cytology, culture sensitivity testing, and even fungal cultures in these instances as well.

So next, I wanted to briefly touch on proventricular dilation disease. The reason that I mentioned this is that fluoroscopy is really, really, really helpful in these instances. So avian bornaviruses are the causative agent of proventricular dilatation disease, but this is actually probably more accurately known as avian ganglioneritis because many systems of the body can be affected by avian bornaviruses and then actually in some cases, these cases will actually lack proventricular dilation as well.

So it's a viral disease associated with the central nervous system, and clinical signs include impaired gastrointestinal motility and function. It is a progressive neurological disease that unfortunately is inevitably fatal once clinical signs develop. And the predominant clinical feature is parrots that have a dilation of the proventriculous and accumulate food within their secondary to the intestinal hypomotility.

But there are multiple genotypes available. They are avian born virus 1 to 5. And as we've mentioned, many, many clinical signs, so.

Ataxia, difficulty perching, abnormal perching. So this bird here on the left hand side was a new bird to the owners. They brought her to us because she slept funny.

Yeah, yeah, she did sleep real funny. But she was also regurgitating spectacularly as well, which they'd read online was a hormonal thing, but unfortunately, after fluoroscopy, we essentially proved that she had PDD. So they can have seizures, they can be demonstrating blindness, weight loss as well, regurgitation and proventricular intestinal dilation, but eventual death, sadly.

Now, affected birds may show neurological and or gastrointestinal signs. They can also show feather damaging behaviours, but actually the scientific evidence for the causality of this is, is actually pretty lacking. As many as 15 to 40% of normal healthy birds have also been positive for avian borna virus.

So there's a lot of carriers out there, essentially, which means that it's not just a disease that plays a role in this. It's got to be host specific factors such as the species, age, level of immunosuppression that plays a role, as well as that avian bornovius genotype. Transmission is fecal-oral, but certainly in the literature, they seem to be theorising that there might be a respiratory route of infection as well.

And the diagnostics, so. In the classic form of the disease, we're gonna have decreased motility or blockage of that proventriculis that results in the dilation of the gastrointestinal tract. Subsequently, birds are gonna be beginning to regurgitate their food, pass undigested food and sadly ultimately die of starvation.

They can obviously have the neurological signs that we've mentioned previously as well. Now plane and contrast radiography are really, really helpful, but fluoroscopy really, really helps with the visualisation of the often severely dilated proventriculous. We can, see this on plane radiography and contrast radiography on the left side of the synomic cavity.

Ventriculous and intestines can also be dilated, and contrast studies often reveal prolonged transit times throughout the gastrointestinal tract. So if you're doing your serial radiographs, those timings that we discussed previously, and it's not really moving in the way that you would expect, that's a red flag for PGD. Serum chemistry and hematologies are often normal, however, we can have elevations in creatinine kinase, we can have elevations in our hedge phone numbers, we can have hyper hyperprotemias, and sometimes even a mild anaemia that non-regenive anaemia chronic disease.

Some birds can also present with gram-negative clostrilio enteritis, so in any bird is passing undigested food, we really should be performing faecal analysis as well. A differential diagnosis is often performed with histopathology of either the crop, proventriculous, ventriculous or an adrenal gland, actually. But you're gonna need a large biopsy and you're gonna need at least one viable vessel.

Send that off for histopathology, and we're gonna have characteristic mesenteric ganglionitis lesions, which this virus specifically causes a lymphoplasmacytic infiltration of that nerve ganglia supplying the musculature to the gastrointestinal tract and the central nervous system. PCRs are often available and we can do this on urine, faeces, cloacal swab, but shedding is intermittent, so we can have false negatives. If we want to be minimising the risk of these false negatives, maybe a freely pulled faecal sample is recommended.

Serology is also available, but again, not all birds that are affected. Have clinical signs. So from a positive point of view, that can help with screening and with quarantine.

Now with regards to treatment, lots of options available. Sorry, but not many, not much reported in the literature. So meloxicam is used a lot.

There's very little evidence that it actually works. But the reported doses are 0.5 to 1 mg per kg, given orally, 1 to 2 times a day.

Other NSAIDs that can be considered ruin a coccib, 2 to 10 meg given intramusculine for 4 weeks and then monthly. Or celecoxib, giving it 15 to 30 mg per kg orally twice a day, or in severe cases of neurological changes, 30 to 40 mg per kg given twice a day. Now, the effectiveness of these seems to, to, to vary, tends to be really, really linked with the onset of treatment and the stage of the disease at that onset of treatment.

Cyclosporin has been anecdotally suggested at 10mg per ki given orally twice a day, where birds have become refractory to NSAIDs, and gabapentin has been used at 10 to 25mgki given orally twice a day. There are no clinical studies proving that this works or not. It does seem to be very much anecdotal.

And alongside these medications, we want to be implementing supportive care. It's more frequent liquid diets, prokinetics such as Sisyphide or metoclopramide, and then unfortunately, antibiotics and antifungals for the inevitable secondary bacterial and fungal infections. Now this virus is, is not environmentally stable, which means that it can be destroyed with soap, bleach, inactivated by ultraviolet light and desiccation.

So hygiene in the environment as well is really, really good. But from a diagnostic point of view, fluoroscopy, really, really, really, really helpful in these cases. If you do not have it yourself, a lot of referral centres do, so get in touch with them and see if that's something that they would be able to help you with.

And then finally, before we get to our postmortems, we're gonna briefly touch on reproductive disease. So, obviously we can see this in a lot of birds, but predominantly it's gonna be our backyard poultry, specifically our expatriy hens. A wide variety of clinical signs, but they tend to be pretty non-specific, so depressed, lethargic, anorexic, fluffed up bird, essentially.

And obviously these various different types of reproductive diseases, which can include chronic egg laying, dystopia, oviductal or ovarian disease and selomitiss, as well as in the males having orchitis or even phallus prolapses, it's gonna vary the clinical signs that we specifically see. So bear in mind that reproductive disease can be non-specific. Obviously, if the bird's straining and it's got an egg stuck half out of its cloaca, it's pretty obvious what it is.

From a diagnosis point of view, your baseline bloods can be incredibly helpful. So regardless of the sex of the patient. And if we've got a chronic egg laying or dystopia, we want to be really considering doing an ionised calcium when we're taking our blood sample.

Diagnostic imaging such as radiography, both plane and contrast, CT MRI, that ultrasound that I mentioned previously could be really, really helpful in our cases of selomitis and endoscopy, all really, really helpful in these cases. Personally, any sick bird that I, I have, I tend to perform a faecal analysis on, but especially our backyard poultry to make sure that we don't have any underlying parasites that could be complicating the issue as well. Now in cases of selomitis, as we've mentioned previously, this is when we're gonna be wanting to perform our ventral midline approach for endoscopy.

This is also the area that we can be performing our sallomacentesis as well. And treatment again, it's really, really gonna be depending on, one, the, the, the underlying cause, which hopefully all your diagnostics will help you figure out, OK, what type of reproductive disease are we dealing with. But it is inevitably going to involve swift stabilisation and probably a combination of medical and surgical interventions.

And then finally, admittedly a pretty morbid way of summarising a webinar, but the reality of dealing with any sick bird is that losses are entirely possible. And this is because birds are gonna hide those clinical signs until they are literally about to drop. So, they're going to often be presented to you in a severely debilitated death state resulting in death.

And it is good practise to really know how to perform an accurate postmortem, especially if the bird that has died is one of many. It's gonna help you determine how at risk are any of the other birds, but also it's gonna provide you feedback for the way that you have managed that case as well. So postmortems should be performed as soon as possible after death.

Body should be refrigerated, never frozen, and the patient, if you're having to euthanize it rather than than it passing away by itself, you want to avoid this in certain ways to perform lesions forming in various different target organs. So the best way of doing this is an overdose of gaseous anaesthesia. Or second to that, very small amount of intravenous barbiturate.

Now because there are many, many zoonotic diseases that can affect birds, the performers should be protected, and postmortems performed in a well lit and well ventilated area, ideally under a fume hood with a performer wearing protective clothing, gloves, masks, and goggles. The area should also be able to be thoroughly disinfected. Now, prior to performing your postmortem, you want to be making sure that you have got an accurate weight for your patient and that you are assessing all external identifying factors such as feather tattoos or ring numbers.

We want to be assessing assessing the patient's body condition score, it's a tegument, it's plumage, checking through all of its orifices, checking the preen glands, and don't forget the underside of the feet as well to make sure that we haven't got any case of bumblefoot. Now there are various different steps that we're gonna go through, but we want to be making sure that regardless of the step, and regardless of the order that that you do it in, I, I'm gonna take you through the order that I was taught to to do it in, but essentially, if you're performing posts on a regular basis, get into a habit, make good recordings. And get someone to help you or or dictate your and record your findings so you're not kind of cross contaminating your notes.

So if you're taking pictures as well, make sure you're not postmortem a bird and then touching your phone or your camera or whatever reason, just from a hygiene point of view. So, we have assessed our patient externally. We then want to make an incision through the skin made midline just below the sternum, to the mandible.

We want to be assessing the underlying musculature, assessing the subcutaneous tissues, assessing the amount of, of, of fat, if any, that we have there, making sure that we're noting any sort of abnormal colour changes. Next, we want to be incising just according to the sternum, taking care not to damage that liver that sat underneath with the aim of removing the keel bones and associated pectoral muscles after you've assessed them. And you can be getting a big pair of scissors cut through the ribs, the coracoid bones and the clavicles to do so.

Once the keel bone has been removed, we then want to be assessing the air sacs and the organs in in in situ. Now, the air sacs, they should be transparent, they should be glistening. Any abnormalities to that, we need to be taking our samples, cytology, culture sensitivity testing and histopathology.

Next, I personally, I assess the heart, look at the amount of, pericardial fat, the colour of the pericardial fat, the colour of the the heart itself. And we think and then remove the heart by transecting the great vessels. The heart should be cut open, assess the lumen, the wall thickness, cut open the great vessels again, check their thickness, because, thickening of the great vessels can be associated with an atherosclerosis.

While we're in that area, we can also be assessing the thyroid and the parathyroid glands. One thing that I tend to look for in this area when I'm assessing the pericardium specifically, if we kind of have like white chalky deposits, that could be a sign that we've got a visceral gout. Next, I assess the liver, make sure that it's not swollen or discoloured, we want to be cutting that surface in a number of areas and assessing those underlying structures.

Hepatomegaly, well, why doesn't hepatomegaly occur in, in birds? So there's many reasons for, for that. But if we've got extensive necrosis, it might be a herpes virus, if we've got any discoloration such as yellowing, we could be dealing with a hepatic lippodosis.

Next, I assess the gastrointestinal tract. So we'll be assessing this in situ, and then removing that in in, in, in after we've assessed it in place, basically. Now I start the crop, and I basically snip above the crop and start, for want of a better way of putting it, peeling that gastrointestinal act and and breaking down those the, the, the attachments within that salamic cavity.

I would then line up my gastrointestinal tract, separate to the bird to avoid any sort of contamination, start opening it up and taking samples, assessing thickness, discoloration, when we're in the gizzard, assessing the coiling layer as well, making sure the size and the shape of those internal structures is as I would expect. Take any measurements as appropriate, and if I'm. Taking out some of that gastrointestinal content, I will then have somebody perform a faecal analysis on it or a microscopic analysis on that gastrointestinal content, not just a direct assessment, but also a flotation and even sometimes spinning that down and looking at the sediment from that floatation as well.

Next, I assess the spleen. So this should be assessed for size, colour and shape. It's normally small, pale and round.

If it is enlarged, well siticosis until proven otherwise, as far as I'm concerned, and, with patria's disease, it can be very small, sorry, very swollen, but it's cherry red, really, really bright red colour, so we'd be suspecting that if we're seeing any of that. Next, I assess the pancreas. Pancreatitis happens for many, many reasons.

Tends to be a lot of viral problems such as adenoviruss and polyoma, but also chlamydia and avian influenza. So worth bearing that in mind, certainly at the moment we have an avian influenza outbreak if you are performing postmortems on any wild birds, you really need to be protecting yourself and maybe considering not doing that at the moment. Next, the neurogenital tract.

Now females have only the left ovary and oviducts, males have 2 testes, and these vary massively depending on the time of year and the species. There's two little yellow blobs next to the gonads, they're the adrenals, bright, bright yellow. And then the kidneys are going to reside in the renal fossa, and there are 3 poles to the kidneys, which as you can see in this budgie here, had a nephritis.

Kidneys are humongous and discoloured, with dilated ureters, in, in this bird. They sit in the renal fossa of the sin sacrum, and enlarged hyperemic kidneys can be seen with a nephritis. Pale, swollen and friable kidneys can be associated with renal degeneration.

Next, I assess the lungs. Again, you can see these quite nicely in this picture here. I'll be taking swabs and samples of cytology and histopathology, as well as culture sensitivity testing, especially if that bird has presented with respiratory problems.

And we can be sampling any discrete lesions that might be suspicious of of aspergillosis at that time as well. And then finally, I'll be assessing the beak and the contents within, opening up the trachea all the way up to the mouth and having a look inside and taking any samples. If you can't quite look inside the beak, you can snip the beak commissions and just open that beak a little bit a bit wider and assisting the cloa and the glottis.

And then finally, the skull. We take the skin off that, look for any signs of, of injury. We can remove the bone of the skull with some rounds and then we can examine the brain.

If we had any suspicion of ophthalmic disease, we can also take the eyes, and we can send those for ophthalmic assessment as well. That's it. Thank you very much for listening.