Hello and welcome. Today we will discuss about chronic enteropathies in dog, and we will try to go together through a stepwise approach in order to better understand and remember how to investigate these cases. First, we have to remember the definition of a chronic enteropathy, and that means that there are chronic or recurrent signs that have been occurring for over 3 weeks.
And that these signs obviously are related to the gastrointestinal tract. It's usually associated with evidence of inflammation on histopathology. But before we reach that diagnosis, we need to exclude all of the other causes.
So as you can see on this diagram, these dogs can present with diarrhoea, vomiting, weight loss. The list of clinical sign is actually quite long and also includes changes in appetite, hematochezia, which is the presence of blood in the faeces, presence of melena, which is digested blood. Also, anomalies at emitting faeces such as dyskesia or tenismus, as well as constipation, which is an infrequent or difficult evacuation of dry and hard faeces.
We can have the presence of flatulence, boring me, abdominal discomfort, or ascites, and all of these clinical signs or any of these clinical signs should make you suspect that there is a gastrointestinal disease in your patient. The clinical history is also very important to obtain and obviously related to the reasons for the presentation to your practise, and that will include the actual description of the clinical signs by the owners associated with their duration, trying to determine if it's an acute onset or more of a chronic occurrence. It's important to ask questions about a pattern.
Is it associated with meals? Is it not associated with meals? It's very important to obtain a dietary history as well, and to know the dietary history of your patients, such as their habits around scavenging.
Are they given human food, table food, all of these details are very, very important for gastrointestinal disease investigations. Finally, it's important to also know the infectious risks to which your patients are exposed, such as worms, for example, so always asking the worming status of the patient, exposition to other dogs or to wildlife is also quite important. When discussing patients with diarrhoea or constipation, the Bristol stool chart is always very useful to help you and the owners finding an agreement on what they describe, so that you know exactly what you're dealing with.
That, chart will rank the consistency of faeces from 1 to 7, knowing that 3 and 4 are usually considered as normal. As a reminder, diarrhoea is caused by an excess of faecal water, and that will decrease intestinal absorption and stimulate more intestinal secretion, leading to abnormal timing for emission of faeces and increased volume, often associated with that. We try to differentiate between small and large bowel diarrhoea to try to locate the disease a bit more precisely when our patients have this clinical signs.
Here you have a table where we have summarised most of the changes associated with a small or large bowel. And you can see that in a lot of instances, it kind of overlap. So, in some patients, you will not be able to determine if the bowel, if the diarrhoea is originating from the small or the large bowel, and it is possible that it's originating from both, in which case it would be called mixed diarrhoea.
Some of the important differentiation that we have to do are differentiation between melina and hematochezia. So the melina is a very dark colour, stool, and it's associated with the presence of hematin, which is an oxidised form of haemoglobin. So it's a direct indication of an active bleeding high enough in the GI tract that the haemoglobin has time to be oxidated and that the blood is digested.
Therefore, you have to consider an origin for the blood to be either the GI tract. The oral cavity, the oesophagus, the stomach, or the small bowel, but also the upper and lower respiratory tract because if there is a bleeding in the nasal cavity and the patient is swallowing the blood, then it can have a presence of melena. Similarly, if the patient is coughing up blood and swallowing it, there could be melena emitted in his faeces.
And it's important to differentiate Milena from hematochezia. So hematochezia is a bright red colour, . Presence of blood mixed with faeces.
So it's fresh blood and that often indicates a bleeding from the colon or from the rectum. It can be very transient and very acute, and it's something that we observe fairly frequently in patients that are hospitalised for 24, 48 hours, you know, in a new environment and associated with stress. It doesn't rule out completely, a bleeding a little bit higher up because sometimes the peristalsis could be increased and therefore the blood would be not as digested as you would expect from coming from the upper GI tract.
Another important distinction to do is a vomiting versus regurgitation. Vomiting implies the active contraction of the abdomen to push back up and out the content of the stomach, whereas regurgitation are non-controlled emission of water or food content that was either sitting in the oesophagus or in the stomach without any Conscience or any involvement of the abdominal contraction. Looking at differentials for vomiting, we can have upper gastrointestinal disease involving the stomach or the duodenum or both.
And these diseases can be obstructive, such as a foreign body or a mass which would create a mechanical obstruction, or they can be functional, such as an interception, for example. We also have metabolic diseases that have been reported to lead to vomiting, such as renal disease, liver disease, pancreatitis, and a few endocrine diseases as well. Regurgitation is often associated with an inflammation of the oesophagus or an anatomical anomaly such as a megaesophagus or .
A partial or a complete obstruction of the oesophagus with distension, aborally to the obstruction. Weight loss is an important clinical sign. It can be very subtle, but it's a very essential clinical sign, and it's something that you can pick up in your practise very regularly if you weigh your patient at each and every visit they do.
In some cases, it is the only clinical sign that will indicate that there is a gastrointestinal disease. So it is very, very important to monitor the weight. If you have a patient for whom the weight has been varying quite a lot, you may want to log as well as the weight, the body condition score, to try to determine if your patient is overweight, underweight, or ideal.
This chart and the one that is displayed here is from the WHAVA are available for all of the vets, and they, they are very important for you to understand and to be able to apply to your patient. It is important that if there is any weight loss, you question the owners to know if it's an unintentional or an intentional weight loss. Did they change the diet?
Did they reduce the diets, the amount per day? And it's important to, you know, determine and communicate with the owners what the maintenance body weight of your patients should be, and then readjust the nutrition based on that. The mechanism associated with weight loss increased a decrease in calorie intake, so that's why it's very important to ask about the eating habits to the owners, or an increase in metabolic demand.
There could be an accelerated energy loss. There can be an inability to utilise the ingested calories, although that is difficult to prove and quite rare. .
And it's important as well to ask about the quantity that the dog eats. Some dogs will seem interested by food, start eating and then be disinterested and not finish their meal. Assigned with the body conscious score, we want to evaluate the muscle score of the patient.
And that is also something that can be very important to record, because it's a good indicator of health and of caloric intent as well as good nutrients in tech. Cachexia, starvation, malnutrition can lead to weight loss. Achyia is a very marked activation of the inflammation cascade associated with an increase in resting energy expenditure as a consequence of an altered protein, fat, and, carbohydrate metabolism.
So it's often associated with chronic diseases such as chronic kidney disease, chronic hepatitis, and things like that. So, in summary, it's very important to have a very thorough examination of your patient, a very thorough physical examination, including a body condition score, a muscle condition score, also a rectal examination, which will allow you to assess the faeces consistency. Knowing if they are dry, if they are liquid, trying to eventually character characterise them with the brittle stool chart with the owners, and including as well an abdominal palpation to see if there is any pain, any mass, any distention, any ascites that you can pick up while starting your consultation.
Then you will want to consider the differential diagnosis for chronic GI disease. And it's easy to remember that there are two very big categories for all of the GID disease that you have to consider. One is extra gastrointestinal, and the other one is intra-gastrointestinal.
Extra gastrointestinal diseases include all of the metabolic diseases that will have an impact on the appetite, on vomiting, or on absorption of the nutrients. It's a very long list that represents this metabolic disease, but the main ones are presented on that slide. Addison's disease can lead to poor profusion of the guts and acute or kind of chronic waxing and waning clinical signs such as vomiting or diarrhoea and should be considered for any patient that will present to you with acute GI signs.
Renal disease often associated with vomiting but can lead to constipation as well, associated with the dehydration resulting from the the kidney disease, liver disease, pancreatitis, and exocrine pancreatic insufficiency have all been associated with some degree of vomiting or diarrhoea. In the intragastrointestinal diseases now, we have to consider a few subcategories and these categories are infectious, immune-mediated disease. Neoplastic disease or a foreign body.
Infection can be bacterial, viral, fungal, protozo. It will depend where you practise and so it's gonna be very important for you to know which type of pathogens are present in the area that you practise in. In Ireland, we don't have a lot of, Fancy infectious diseases that will reach the the digestive tract, but your common parasites and a few bacteria and bacterial overgrowths can be associated with that.
In terms of immune-mediated diseases, we can have a hypersensitivity or a food responsive antopathy, or we can have this big umbrella term of the inflammatory bowel diseases, and we will see that they actually encompass very various and different type of disease as we go along the presentation. Neoplasia of the GI tract in dogs, most of them are carcinomas or lymphomas. More rarely, we will find a gist, which are gastrointestinal stromal tumours, so a soft tissue sarcoma of the GI tract, and mast cell tumours as well.
So in terms of investigations, as you know already, we, we need to collect a good history and we already went through that together. And then you will perform a thorough physical examination as we just discussed. And finally, you will want to start to investigate a bit more in depth with blood biomarkers, faecal analysis, imaging, and eventually further investigations.
In terms of blood biomarkers, we often start with a general blood profile, and that will allow us to determine the markers of any metabolic disease that could lead to gastrointestinal signs. We can also measure some GI specific markers to assess for gastrointestinal absorption, for example. When investigating the metabolic diseases, it's important to consider endocrine testing and liver function testing on top of your usual biochemistry profile.
Other things that you can consider would be a CPLI, for example, in vomiting dog, it's important to rule in or out pancreatitis. A TLI if your patient is of the right breed and the right age for exocrine pancreatic insufficiency, and if the clinical signs are matching the usual description of that disease. Binance stimulation test and ammonia levels are part of the liver function testing, and that's gonna be important for you as liver dysfunction, liver disease can lead to vomiting or diarrhoea.
Finally, from an endocrine point of view, you can measure basal cortisol or more easily perform an ACTH stimulation test to rule out Addison's disease in your patients. Finally, when looking at GI specific markers, you can measure B12 or cobalamine and B9, or folate to try to assess for the gastrointestinal tract ability to assimilate nutrients and absorb these nutrients properly. So folate or vitamin B9 represent a marker of good health of the proximal gastrointestinal tract.
They can be associated with bacterial production, and therefore their changes can be interpreted as bacterial overgrowth, and they are kind of a good surrogate for a marker of nutrient absorption from the food. Vitamin B12 is absorbed in the distal gastrointestinal tract and is a good indirect surrogate for food and nutrient absorption in the patient. When looking at anomalies that will affect folate, you could have a hypoaliteemia if you have a very severe mucosal disease, of the proximal dudenum and therefore you can't absorb your folate anymore.
Folate is very abundant in the diet. And is absorbed in the proximal duodenum and usually is present well in excess. Folate can also be produced by some bacterias that are present within the GI tract, and therefore, the change in the gastrointestinal flora may change the value of your folate, and that could lead to hyperthalitemia, for example.
Hyperthalitemia is also been associated with exocrine pancreatic insufficiency. It is essential to remember that a normal concentration of folate does not rule out a chronic antopathy and further investigations are therefore warranted. Cobalamine is a soluble vitamin that is absorbed from the diet through a complex receptor-mediated process.
So this is a figure from a paper from the vet Journal in 2013, . Where you can see that the dietary cobalamine is attached to the foods proteins, and The cobalamine is separated from these proteins and freed, where then the cobalamine is gonna bind to the R protein cobalamine, complex, and that will travel in the proximal duodenum until it reaches the. Papillae, where the pancreatic enzyme are gonna dissolve that complex, and then the cobalamine will be bound to the intrinsic factor which is also produced by the pancreas.
So here you understand why if you have a low cobalamine, you will need to test for exocrine pancreatic deficiency because the intrinsic factor is mandatory for the absorption, the proper absorption of cobalamine further down in the GI tract. And in the distal ileum, there are some specific receptors that are going to be able to receive the intrinsic factor cobalamine bound and separate them to then excrete and transport the cobalamine into the blood. So disease disease that can affect cobalaine dietary deficiency is very rare, so very low value of cobalamine probably represents a very chronic state of malabsorption.
It is possible that there are diseases that will impair the expression of the cubalaine intrinsic factor receptors in the ilium, and that has been shown to be secondary to inflammation of the mucosa or bacterial overgrowth, with bacteria that will compete, and use the cobalamine, preventing it to be available for the patient to absorb. And that is just a consequence of these biases. Hypercoallainemia has been associated with extreme parental administration, high dietary content, but also some cholestatic liver disease.
Again, a normal concentration of cobalamine does not rule out a chronic enteropathy, and therefore, further investigations are still warranted. When we are looking at our diagnostic approach, we have these symptoms of chronic enteropathy. We have ruled out our systemic disease with our biochemistry profile.
We have ruled out our endocrine diseases with our special endocrine testing, the basal cortisol or the ACTHIM test, and we've ruled out, or we are waiting for the results of the absorption disorder investigation, with the B12 and the B9. In the meantime, I would recommend to send for a faecal analysis, and that's going to be the best way for you to assess for infectious diseases such as Campylobacter, salmonella, or clostridium if you were to investigate for bacterias, and you could for that perform a faecal culture. You can also perform a par virus snap test if you suspect that your patient has yvovirosis.
Run worm, hookworm, tapeworm, whipworm are all common in dogs GI tract, and so knowing the warming treatment that the patient has received is going to be essential to know if they might be present or not, but sending the faecal material for a faecal analysis and eventually a Burma flotation. Is important to try to show the presence or absence of these worms. And similarly, some protozoa will be picked up during the faecal analysis of the patient faeces.
Even if the sensitivity of this test is not great, at least, if you show that it's present, then you can initiate the proper treatment. And we have seen a few dogs coming with very like underwhelming clinical signs that were positive for Georgia, for example, and they live in like other areas with the dogs or they go to the dog park. So it's very important to know and very important to address.
Imaging, imaging of the abdomen seems like a logical next step once your blood and your faecal analysis haven't given you any good lead and you still don't know what is happening with your, with your patient. Radiographs of the abdomen are known for having a poor sensitivity. You have like a two dimensional projection of a 3D 3D structure, and there is obviously a lot of overlap between all of these organs, so it can be difficult sometimes to see something very clearly.
So ultrasound has been shown to be superior and more accurate for the GI tract. However, radiographs are still used for emergency assessment of an acute vomiting patient or an acute diarrhoea patient looking for an obstruction or something that would require a surgical intervention right away. There have been a few studies looking at that.
This is one of the most recent one, looking at some ratios between the size of the the the diameter of the gastrointestinal loop and the thickness of L5, and they've been able to prove that it was very unlikely that the patient would be obstructed if the small intestine maximal thickness. Divided by L5 was less than 1.4, or if the maximal thickness divided by the minimal thickness was less than 2, or if the maximal thickness divided by the average thickness was less than 1.3.
Similar ratios have been shown that they were associated with very likely obstructive patterns, if they were very increased all of the ratios, which means that basically the SI max is much distended. However, you can see that there is a grey zone where if your patient is in between the two, you actually have no idea if it's very likely or very unlikely that they are going to be obstructed. This paper also showed that there was.
A low inter-observer agreement, so the ratio between one observer to the other could change, and therefore their interpretation is a little bit subjective. So ultrasound has been the preferred mode of investigation for chronic enteropathies, because we are looking at something probably structural, pro probably happening in the in the GI wall, so in case we could see it, we use ultrasound. This image depicts the normal appearance of the gastrointestinal tract on ultrasound, and it's a multi-layered, organ wall, with a very thick mucosa, and then you have a very bright submucosa, a muscularis that is this darker line, just after, and finally, a serosa.
It's important when you look at the abdomen on ultrasound, that you are very thorough, look at all of the organs, but for the GI tract, it's important to acquire images where you can determine the the wall thickness and the wall layering to see if it's preserved through and through. You want to look at the layer ecogenicity and the layer relative thickness from one compared to the other. You want to look at the motility and be able to assess the peristalsis of the stomach during the test.
You want to look at any abnormal periintestinal exogenicity that could suggest an inflammation or an infection or a septic abdomen, for example. You want to also search for free fluid, which would be probably related to the same kind of differentials or could be associated with a very low protein level in the blood as well. You want to look at the original lymph nodes?
Are they abnormal? Are they thickened? So you need to be very thorough when you investigate and have a look at this GI tract with ultrasound.
There is a very recent study which we will go a bit more after in detail, but overall showed that ultrasonographic anomalies were only present in 37% of the cases. So that means that less than half of the cases that are presented to a referral hospital for. Suspected gastrointestinal disease.
Only 40%, let's say, of them have anomalies on their ultrasound. They also designed the study so that they could compare across the different types of disease, and for ultrasound, you can see that the changes are present across all disease type, and there is nothing that is very specific or pathognomonic or of any. This type between inflammatory diseases such as lymphoplasma cytic enteritis or reophilic enteritis to more neoplastic diseases with the lymphomas, but even some of the criteria are overlapping with the normal biopsies.
And that corroborates probably the oldest paper we had, . Looking at this, which was published in 2005 by a team from Bristol, and, they look at the thickness of the GI wall in dogs with IBD compared to dogs with presumptive IBT and compared to healthy dogs, and basically what they managed to show is that. There was a complete overlap, and you can see in these bar graphs that the white bar represents the healthy dogs, the red bar represents the suspected IBD and the blue bar represents the confirmed IBD.
And between 2 and 5 millimetre for the deanum, and between 2 and 5 again for the genome, there is the presence of the three categories. So it's very difficult to establish cutoffs, and I believe this article suggested that there would be a grey zone between 4 and 6 millimetres of thickness, and that above 6 in the duodenum and above 6 or 7, I can't remember in the genum, then we could confidently say that it's most likely to be neoplastic, to be inflammatory with IBD. So, not the best test that we can have.
We also have more and more studies and also of course an improvement in the quality of the machines that we are using. And so they have been very recent reports, for example, this report of the description of the changes that are observed with inflammatory bowel disease, and this was one of the first case series of dogs that have a relative thickness of their muscularis that is abnormal. So, The muscularists will be This Layer here.
Or this layer here, the black dark layer, and it should be just a very thin line and it's very, very significantly increased in all of these patients. So the ultrasound is not specific, it's not sensitive, but it's a bit better than radiographs. It can still give us some help, .
Although there have been two recent studies looking at what does the imaging provider based on the clinical signs for which the patients are presenting, and they've shown that for the population of those that had diarrhoea, only 55% of them were prescribed an abdominal ultrasound by their attending clinic. Both in an acute or chronic phase, and there was no anomaly affecting the, the intestine directly in 44% of the dog, . There was only 3% of patients for which abdominal ultrasound was considered to be a diagnostic without any further testing needed, and that was dogs that had a vascular anomaly such as a polysystemic shunt or that had a foreign body that needed to be removed.
Now, when looking at the population of dogs that were presented for vomiting, the radiographs were useful in 33% of the cases. Where they allowed to identify a foreign body and to send the dog for a corrective surgery. The ultrasound were helpful in 3 33% of the cases, so they were not exactly measuring the same things, .
And The ultrasound was also deemed to have only picked up on very important things such as neoplastic disease and foreign bodies again. So yes, Ultrasound of the GI tract is often unrewarding when you have an inflammatory bowel disease when you have a chronic enteropathy. However, it is important to know that ultrasound is a very good way to rule out a lot of underlying conditions that can lead to chronic enteropathies.
This is a table of the anomalies and the diseases that have been associated with them. And again you can see that there is an overlap between the first category and you have IBD, you have lymphoma, you have using enteresis, you can see also some overlap with fungal disease, for people that work in areas where this would be present with GI fungi, or the fungi, fungal disease associated with, well, overlapping in terms of changes with neoplastic changes. But the ultrasound is very good at picking up masses.
This is a very abnormal bowel. You can see that the layer is the layer organisation is lost, and we have like a thick mass and there is not a. Possibility to distinguish anything.
So the ultrasound would be very good to pick up these things even though it's more rare, and also looking at surrounding lymph nodes and other, indirect markers of maybe a neoplastic process. So in summary, you have a patient that has symptoms of chronic enteropathy. You've ruled out your systemic disease, your endocrine disease, you have ruled out your infectious diseases with a faecal analysis.
And so now you are suspecting a primary intestinal disease because your imaging didn't show anything specific. That could be sampled or a mass that would have to be removed. It's only either no changes that are visible or very diffuse changes throughout the GI tract.
At this stage, you are left with absorption disorders that you can you can evidence by measuring a B12 and B9. And all of that points towards an infiltrative disease. Even your absorption disorders are secondary to an infiltrative disease, and these infiltrative disease could be.
Oh, sorry, and these infiltrative diseases could be either inflammatory or neoplastic. So the next step is to perform biopsies, biopsies of the GI tract to try to obtain samples, which will contain these inflammatory cells or the neoplastic cells, and the less. Invasive way to perform this sampling is through an endoscopy and the gastroduodenoscopy if you go into the duodenum and the stomach, or a colonoscopy if you think that the diarrhoea is mostly large bowel and you want to sample the colon in your patient.
So back to this paper, that's the, the paper that we just discussed in the ultrasound section. They were looking actually at patients that had an endoscopy and had biopsies, and they showed that. 68% of the patient had lymphoplasmatic enteritis, so the most common type of inflammatory bowel disease.
They also had 9% of the patient that had an useophilic enteritis and 5% that had a mixed enteritis, so that's when you have more than one type of cell that are infiltrating the . The mucosa and the laminna propria. Only 2% of these patients had lymphoma and obviously as you can see, there are no other .
Neoplasia that are listed there because if you identify a mass, then it's game over and your patient needs to go to surgery to have the mass removed. So obviously they could not be included in that study. It's also important to note that 16% of these patients had no histological changes.
And, and, and that is for me, the most surprising, like it's definitely something we, we see. I would not have thought it was such a high number, so I think this paper was quite interesting in in that regard. And these patients have clinical signs, but the changes on histology are not enough for the pathologist to call it anything.
That can come from the collection method and the size of the biopsies that we obtained. You can see on these pictures from a paper about endoscopic biopsies that some of the fragments can be very small, and others can be very big, so the interpretation will vary very drastically between these two types of of fragments. But when you have good biopsies, you can see that they are able to provide you with a normal like.
Architecture of the VA for you, for the pathologist to review and of thickness of the mucosa and sometimes the submucosa as well, to assess the invasion with the inflammatory cells. So good endoscopic biopsies are usually enough and of good sampling quality. Again, surgical biopsies might be indicated in a few cases we discussed about the neoplasia in the previous slides, but also if you think that you need a full thickness biopsy because you have like a thickening of the muscularis, for example, and you know that we will not be able to get the muscularis via endoscopic biopsies.
Then once you have your biopsies, you can consult with the WSAVA for their classification of inflammatory bowel disease. And that would be based on the type of cells that are infiltrating the the bowel. So as I said, lymphoplasmatic is the most common one, and then eophilic, probably the second one.
And then we have a few neutrophilic, which are always very challenging because we don't know if it's immune mediated neutrophilic or if it's infectious mediated neutrophilic. So these patients are always a bit more challenging to manage at the start, at least. We can have a mixed inflammation like we were discussing before, although in this paper they call it isocytic, and then we could have granulomatous, .
Granumatoscolitis is a very specific entity, and so we will discuss it a bit further towards the end. Once you have described the type of inflammatory cells that are present in your biopsies, you will add a qualifier based on the surrounding lesions that might have been identified at at the stage of pathology. And that includes ulcerative versus non-ulcerative disease.
And then a gradation for the severity of the disease, and that can be a little bit subjective from one institution to the to the other. So it's important for you to create your own scale and to be very well used to the pathologies that you're using, so you know how to interpret the pathologist's comments. Now, if we look at the latest update on therapies for these chronic enteropathies, because you have finally reached a diagnosis when you have acquired your biopsies, The treatments are organised as is.
Most of them will be food responsive, and it's been shown in a study that if you were young, you are more likely to be food responsive, and also that food responsive enteritis have a better prognosis for control of the clinical signs and survival at one year after the diagnosis. Traditionally, we used to have an antibiotic responsive category here, although there is very few evidence that antibiotics, unless it's in a very specific case where the infection has been shown to be there, would be indicated to be prescribed blindly. So we recommend to them if they are not food responsive, perform your biopsies and then initiate immunosuppressive treatment, to try to gain control of your IBD.
Finally, some of them will never respond to anything, neither the food nor the drugs. And so some of these patients can be very, very frustrating, but I would say that most of the patients actually do fairly well. So in terms of treatment strategy for your chronic enteropathy, you want to consider a diet trial.
And if your patient has never had a diet trial, if your patient has been exposed to people's food, or the neighbours, the cat, it's important to be sure that if you initiate it, it's going to be well done and therefore it's gonna be strict with only the food that you provide and no treat or no anything on the side. These diets are often based on novel proteins or novel carbohydrate or both. They often present with hydrolyzed proteins to try to decrease the stimulation of the immune system and increase the digestibility of it, but homemade diets can be considered using like whitefish, lamb.
Venison, things that are a little bit unusual and not used very often in pet food. The second arm is the immunosuppressive medication arm. And that usually should be performed after biopsies, because the fact that you're gonna pre-treat before the biopsies could impair the ability of the pathologist to quantify the, the severity of the inflammation.
Obviously we all had cases where we can't perform the biopsies and we have to start them. My first go to would be oral glucocorticoids because it's still the drug for which we have the most evidence that it's actually working. And finally, antimicrobials, and as I said when I was showing the pyramid, I don't think they should be your second step, but there are definitely a few cases for which antimicrobials might be necessary for people working in areas with Gastrointestinal parasites, obviously that's something important to consider but for antibiotics, I think using a faecal culture or a tissue culture is nowadays really, really recommended, and again, we will, we'll go through that together, so.
I would suggest that you save one piece of tissue in the freezer to send later for culture when you get your results, and that could be a piece of urinum or ilion or colon, depending where the lesions that you suspect are the worst are. So immunosuppressive medications, a few of them have been described in veterinary medicine, corticosteroid, as I've mentioned earlier, would be my favourite one to start with because it's the one for which we have the most evidence-based, data. It's a cost effective drug, however, it's associated with all the side effects that, you already know, such as the PUPD, the polyphagia.
The chlorobil has shown good evidence of efficacy, notably for protein within enteropathy. Side effects are rare, and the size of the tablet might be a problem for dosing in some very small sized patient, but it would be my second line of choice in most of these, gastrointestinal diseases. Cyclosporin seems to have more anecdotal evidence in the literature, and it's often known to be an expensive drug if you have a large breed dog.
However, it seems to have a good efficacy in the cases that have been described and that are available in the veterinary literature. Mycophenolate, I put mycophenolate here. It's a drug of the same family as azathioprine and azathioprine has, its place, I think, in the immunosuppressive medications that we could use for gastrointestinal disease.
But I think it's important to discuss about mycophenolate, because there is a question about the evidence, that we have about its efficacy, the, the. The efficient dose and the toxic dose being very close, there is always a difficulty in terms of dosing, and the toxic side effects of mycophenolate are gastrointestinal side effects. So I would try to stay away from it if you have a patient that already has very severe diarrhoea, for example, because it might be very difficult to monitor if you have a lack of response of your patient or if you have side effects from the drug.
Granulomatuscolitis, as I said, is very well described disease in boxers and French bulldogs. It's been characterised by a team at Cornell working with in situ hybridization where they were able to highlight the presence of the DNA of the bacteria within the within the tissue and within the cells, . It's now been described in a few other breeds.
It's been described in a few cats as well. And initially it was shown to respond to extended courses of fluroquinolone because it was an E. Coli that was growing.
So 6 to 8 weeks of E. Coli and with sequential. Biopsies, they had shown with that same team at Cornell that there was a clearance of the bacteria which was associated with resolution of the clinical signs.
However, due to the, apparition of more E. Coli that are resistant to fluoroquinolone due to the extended period of treatment, there have been new strategies that have been developed and it's now recommended to culture the tissue or culture at least the faeces of this patient to try to obtain an antimicrobial sceptability profile. And use the antibiotics that are therefore recommended by your culture.
So my last patient, for example, that I had with that disease, we went and treated that patient with doxycycline because we had a resistant, strain of E. Coli to fluoroquinolone, and so we elected to treat with doxycycline. We just performed the repeat biopsies, but from a clinical point of view, the dog is very much improved and .
And so we, we are hoping that the, the biopsies and their culture will show that we can stop the antibiotics. So the take home message of this webinar, is that chronic antopathies can have very varied ideologies, and that a detail. History and physical examination will help you a lot to organise your differential diagnosis and orientate your approach.
The diagnostic investigation should be thorough and logical to try to eliminate things one after the other before you reach to the invasive tests such as the biopsies, or the diagnosis of exclusion, such as inflammatory bowel disease. Ideally, all of these investigations should be performed before any treatment and . So, yeah, try to, to, to hold on prescribing your steroids or your immunosuppressive medication before you perform the biopsies if the owners are understanding and can afford to do the biopsies.
Finally, the treatments should be evidence-based, and will be kind of a combination of food and eventually, immunosuppressive medication. In some rare cases, antimicrobials if they have granomatoscolitis, but they should be tailored to your diagnostic findings and not just like blindly prescribed. Thank you very much for your attention once more, and I would be happy to answer any question.