OK, thank you ever so much. I think I'll have to give you an updated, for the next one, I think, because it's a little out of date in many places that one. I'll send it along, but thank you very much indeed.

And thank you actually webinar. It's nice to have the opportunity to do some talks on some slightly more specialised area within the exotics and maybe do some more focused bits and pieces. And this is really what this is tonight.

It's, it's a very, very small area if you like, but, very important. Within the practise because we do see a lot of problems with proventricularsis or perpendiculi, however you like to pluralize it. So, what we're talking about, and obviously where this really tends to lead is to what we call proventricular dilatation disease.

This has been known by various names before, Maca wasting disease, neuropathic gastric dilatation. And it got changed from that mainly because other birds, or the parrot spec I should say, apart from the causes have always been affected. So, macaw wasting seem inappropriate, but certainly all the parrot species and cockatoo species can be affected by this.

So neuropathic gastric dilatation seems to sum it up quite well, but I think it comes down to one of these great rules about disease naming is the longer the disease name, the less we know about it. And this is certainly the case in this one. We now seem to have regarded it as being generally considered and agreed that this is actually an avian borne virus infection.

Although there is still some controversy about this, worldwide. As this very much appears to be a reaction to the, virus or to an infectious agent, and other research groups seem to be coming up with ideas that may be other infections, that may, may, may, may share, an immune reaction resulting in the lesions in the nerves, to the gut, which may cause this disease. It is A neurological disease and that's important to bear in mind.

So again, quite predation may be a misnomer here in that it is neurological. So we will see obviously gut signs where the lesions are in the nerve to gut. We may also see CNS signs in some cases and some cases are believed to show peripheral neuropathies as well, which may result in trauma to extremities, or even, potentially feather picking or or mutilation.

However, in the vast majority of cases, the marker sign is a dilated proventricular, and that's a radiographical sign rather than so you can actually directly see on examination. And here we go, you know, the time you see it, there's course a postmortem. And the, the real marker here is you get this very dilated, very thin-walled proventriculous.

And as you can see in this case, it's usually thin-walled enough you can see the seed through the wall, of, of the, of the stomach. Now here's a catch. Not all birds with a dilated perpendriculars actually have PDD.

They don't necessarily have perpendicular dilatation disease. Life would be very simple if we could take one look at the sign and say that disease it has. So actually when we see a dilated proventriculars, what we're actually diagnosing is proventricular dilatation syndrome.

Preventrictor dilatation disease is this avian-borne virus infection, in particular neuropathy, causing the lesion. So dilated perventriculis is PDS, not PDD. Did say it'd be confusing.

So preventri dilation syndrome, what are the differentials? But obviously one of them is in fact PDD or Ain-borne virus infection. Organomegaly may also cause problems where you got pressure on the stomach from, particularly spleen, possibly also liver or maybe even a tumour from the kidneys or whatever.

Hypercalcemia will also cause cause dilatation of the stomach and very important when you do investigate that to be looking at ionised calcium levels, not just total calcium. We also see dilatation of the stomach and reduced motility and heavy metal toxicity, particularly lead, but possibly also with zinc. Proventriculitis, which may occur for a variety of causes.

Bacteria, fungal, all sorts of different reasons may also result in a dilated proventricular. And we may see it with gastric ulceration, and gastric ulceration may occur, due to infection, but can also cause occur due to stress, trauma, and various things like that too. We do occasionally see foreign bodies.

Parrots obviously well known for eating all kinds of strange things, but bizarrely we very rarely swallow them, very rarely get blocked. But foreign bodies will occur, and it's another reason potentially obviously be getting blockage and problems from there. And rarely probably at all which you will see aus and the overall gut stasis and of course, the stomach is part of the gut and may be affected, within that.

It's also important is we talk about parrots, we may blithely talk about parrots. We're talking about 360 odd species, and they will all have different normals for different sizes of organ and relative size organ within there. And so cockatoos and potentially a cleus parrot often have a slightly dilated appearing stomach compared to like a grey parrot or an Amazon.

And I think it's very, very important that you do, we do actually, although we can make generalisations, for example, all mammals will get rabies, but we have to bear in mind that different mammal species will show it in different ways. And probably with these infections too, is a different bird species will show in different ways too. These are not necessarily that closely related.

So what makes you think you might have proventricular disease? Usually the bird is very thin. It's gonna have real digestion problems.

And so they usually get incredibly thin. And this is a typical case here, where you can see the very, very sharp, emaciated, body condition and the keel is really standing up proud and very little muscle around it. The appetite may be normal or increased or even anorexic.

And normally, you will see a normal appetite or increased. However, in the end stage you get very weak, then we'll start seeing anorexia. Classic clinical sign this thing called ain't doing right, ADR.

The bird just isn't quite well. It's not eating correctly or it's not behaving correctly or it's a bit weak, it's a bit slow, it may stop vocalising. It just isn't its normal self, ADR.

Regurgitation has been reported, but actually it's really quite unusual in this. And normally, which kind of makes some degree of sense because regurgitation can occur due to almost increased contraction of, of, of, of stomach or whatever. And in this case, obviously, with the neuropathy, it's not turning over very much.

So unless you get passive regurgitation, it's not gonna happen too often. A really good marker sign is undigested seed in the faeces, and if you see that, then you know you've got to have proventricular disease of some kind. However, you only ever see that in well advanced disease.

It's not an early sign and it's not just because you don't see undigested seed does not rule out proventricular disease. But certainly when you see that, then be very aware this is probably what you, where, where the, where the disease is occurring. The other thing that's important too when you do see, or suspect, and digest seed of faeces is bear in mind that sometimes you got loose faeces and they're being produced on top of seed in the bottom of the cage.

So bear in mind how these things eat. If the seed is still in its hull, it's entire seed, that is not going to be eaten seeds. That's going to be seed that simply just been thrown out of out of the bowl and then defecated on top of.

If the seed has been dehulled, and he's got a kernel there, that probably is going to be seed coming through the special mixed things. And if in doubt, take the bird out of the cage, put it into somewhere clean for observation, see what's passed through there. OK, so we're suspecting, predict disease next stages we radiograph.

OK, dorsal, I mean, that should be vented dorsal. I don't know why I always put ventro dorsal lateral body view. Sometimes plane radiographs may be enough and they see these pictures here we go you see this very big characteristic bulge on the correct side of the body and we can see that that's more likely to be stomach than liver because stomach and liver sit together and create the same shadow on the radiographs and that, that, that's.

That can be enough occasion. Sometimes can be using the enlargement of shadow can be liver enlargement rather than simply perpventricular. In terms of assessing size, we obviously have to compare them to, And that can be tricky in sort of like marginal cases.

And some people are now using a relationship between the key size and the proventricular. So we're removing some of these variability in size of bird, age of bird, that type of thing. And this paper produced by Dennis and Natal, on the radiographic determination of proventriculometer birds.

It's very useful. We can see her plagiarised from the paper, where she's measuring from to, to get this assessment, produces. A ratio in there, anything over 0.52 equals dilation.

You have got to be very careful using this, and if you're going to use it, I recommend you read the full paper and see where it's produced from. And you'll be very careful about rotation and positioning of a bird in that. And it's really hard to assess rotation on a radiograph you've been supplied with.

So it's almost something you always got to take the radiograph yourself and that you visually assess the rotation, as you're taking the radiograph and and looking at it directly. It's really hard to look at a radiograph and say, OK, that's rotated. And discrepancy in this ratio occurred where there's more than 10% rotation, and that's not a lot.

So it's something to be, bear in mind it could be useful, but it's a lot of, potential problems with it. So sometimes you are just using subjective measurement. So again, are playing films enough.

Sometimes they are, but more often than they're probably not. So in those cases, we have to use contrast radio radiographs. And for this we're using barium and in this case, very easy to see, we've got this enormous great set of stomach.

Here's the proventricular. Here's the ventricular, the gizzard, just below it. And obviously, here's the crop just about there with the, with the distal oesophagus linking the two.

The liver, by the way, is the heart here and the liver sits between the heart and the, and, and the stomach. So here it's very easy you got dilated and that's where contrast really comes in useful. Now, again, back to the thing about a large perventricular, don't forget it's differentials.

So you might also obtain radiographs, be seeing things like, not just on stomach sizes, they see some of this which is splendomegaly, sitting right on top of stern and that might be causing some dilation of the ventriculars here. We may also see things, like an enlarged liver, which on the lateral views, I think is clearer than on, on the, venture dorsal. And the reason why because here we got a little bit of, grit in the in the gizzard and you see it's actually pushed much further cordially.

So that's a little bit larger we tell where it's actually had to make. And sometimes we do sampling and stuff, we may find things like this is Mecobacterium or even gastric yeast. So remember those differentials.

So this is important. So we've got dilated now we start doing rule outs and things. So we're going to take bloods.

We're going to do a full profile, we're going to look at liver, can look at kidney, we're gonna look at, calcium levels, ionised in total, can do haematology, all those kind of things. We can do electrophoresis, electrophoresis is really useful in, determining inflammatory processes and often a lot more sensitive than just looking at haematology. I can also give some more clues about what type of information we've got as well.

And probably a stage may well check metal levels. And personally, I probably tend to check lead rather than zinc, especially I've got issues with how much blood I can take and also on cost grounds, whatever. And the reason for that is that zinc is much rarer cause of disease, and also zinc blood levels correlate much more poorly with tissue levels, unlike lead.

Zinc actually does have some physiological uses. Lead that doesn't, so any lead that really can be abnormal. So that's the easy one to measure.

And of course, we have to investigate the proventricular because back to our differentials, many of those were occurring within the proventricular. So you have to do a few things. To do the proventricular investigation, we do the endoscopy if, if possible, but cytology, bacteriology, really important with the gastric wash, and we'll be using our positive contrast, not just to show the size of perventriculars, but also we'll be using it to show and outline any foreign bodies.

To do that, we need to choose the proventrius direct. Yes, you can put barium into the crop, but they certainly if you've got, one of these. Neuropathies, then the transit time may be prolonged, and you could be waiting a very, very long time for that to leave the crop and into the stomach.

And to do that, you're probably end up knocking the bird out several times, and re-adiographing and re-adiographing, and that can be difficult. And of course, every time you knock the bird out, there's a risk of passive regurgitation and potential aspiration of Mary. So we don't really want Do that.

So ideally want to achieve the pro ventricular direct. That's easier, send them easier down than you may think. So here we go.

It's a technique, it's the great power you can see, it's been anaesthetized. We've got an endotracheal tube in place. And now we're passing, this is the dog urinary catheter, reasonably wide gauge, and semi-rigid.

It's very important. It's semi-rigid. And what we're doing is passing it into the crop and then I am holding onto that tube.

We get a side view. What I'm doing is the neck held as straight as possible, and between my finger and thumb, I'm feeling the ventral processes of the spine. So in other words, I'm really locating the midline and I'm passing my tube between my finger and thumb.

So I'm keeping that tube along the midline. And then what I'm doing, once it's through my finger thumb, I'm delicately probing. The back of a crop so I can feel it enter the distal oesophagus.

You do not want to put any force on this this point here, otherwise, there is a risk of crop wall or esophageal wall rupture. And I'll show you a bit more about that later on. But you just want to just delicately poke and when you actually enter the surface, it just suddenly disappear down into, into the, into the stomach.

And it's a relatively easy technique to do. At this stage, I do a wash first of all, and that's for two reasons. One is because I want to get the wash out uncontaminated by anything else I'm doing, but also because I want to see what comes out.

And if I have got a wall rupture, what's going to happen is the saline I put down, and I'm usually using salli for grey I use about 5 mLs of saline. So I put down, it's going to just disappear into the air sacks. I may get some gurgling breathing, or I may get, when I return it, I may get some blood to come back in that case I'm in trouble.

If I put saline down there, I don't get those things, and I return it, I get lots of green fluid here, coming out of the stomach. I know pretty much I'm in the right place and that's fine. And after that, of course, I can then put my barium down much more safely because I know I'm in the right place.

I'm not going to put it in my lungs, so more on that at the moment. Now, that's, if you're just doing a wash. If you're going to be doing scoping, then do that before we do that first of all, because you don't want to do contrast before you scope, you won't see a thing.

To do that, I use a long, about 11 inch, 4 millimetre, 0 degree scope. I would stress the zero degree. The 30 degree scope we often use for endoscopy is actually quite a sharp end, much more risk of trauma.

0 degree is going to have much lesser risk of traumatising. The oesophagus. I use it a 4 millimetre 0 degree scape.

And again, I pass it the same way. So into the crop, feel it underneath the processes and just gently probe and it pushes through. And of course, that's nice.

I can actually see I'm in the right place. I start seeing body organs and a classic laparoscopic view, I know I really have entered the air sacks. And this is what we might see and this is a gastric ulceration, within the proventriculars.

Again, this is you tell it's a raptor we can see chick feather here. So it's not really a true parrot. So scope the proventriculars, that, that can be useful.

If you don't have endoscopy and not doing that, then you go, you start with washing and then on to, onto the contrast. And the contrast you add in last of all, because it means if you're scoping, you, you don't get obscured by by the contrast, it won't affect the cytology when you're doing aspirs and things like that too. Again, the volume is about 5 mL per 400 grammes added in after the washing stuff.

And then as soon as we put the contrast in, I'll withdraw the tube, and then I will, and then take the extra radiograph straight away. It's amazing how fast even in these low transit, gut transit can be in these birds, they can disappear quite quickly. I said, always I say I'm first.

This is a case where I didn't. This is the one where I shortcut it. I just put this, this one I was doing a repeat, contrast on and I just passed down there.

It did feel slightly strange popped through, didn't feel quite right. I put barium down there. As you can see, I have a, a disus or esophageal rupture.

I have barium entering the lungs and stuff. And although the bird recovered quite well after, the, procedure, it did die sooner. Well, about 4 weeks later.

So it's really sad case there. So do. Learn from my mistake and make sure you put that saline down first of all.

If you put saline into the lungs, yes, you're getting a reaction, you should probably get a nasty infection, but probably something you can cope with and it should be OK. If you've and amazingly the esophageal ruptures healed very well indeed. But barium in there, the lung damage is really quite extensive.

So this is what you should get. This is a classic, dilative, proventricular. We can see there's, there's filling defects from food and stuff in there.

We see just how big that proventricular is there too. And also, this is taken within 2 minutes of the, barium going down. And this is a PDD case.

But you can see it's already entering small intestine, also see how dilated that small intestine is. So, you know, you do want to do this quite quickly. Now just to throw another spanner in the works, and not all cases of PDD actually have an enlarged and ventricul proventrix so you're looking at things through there too.

Occasional plane rides, you may see this, cloal Ay, that's saying I've seen in a few cases. And the other thing too, this bird here as you can see has got a very nice normal sized proventry. But look at the size of the small intestine, and this duodenum is really, really dilated and really.

So you may see that occasionally in different parts of the gut maybe. Because transit time may be affected, some people like to use fluoroscopy, and if you have that that, capability, fluoroscopy can be done consciously you can watch that go through there and that can be very useful indeed. So, we've done our, testing, we, we, we, we've done lots of washings, we've done lots, lots of results that we've got psychological results we've got, we've seen an also maybe we got some interesting bacterial yeast growing down there.

We do actually have now decided, are those findings primary or secondary? In other words, did the ulceration infection you're finding in that proventriculars cause the me? Or is the atonic stomach actually encouraging infection and ulceration from there?

In other words, all these findings can be primary or they can be secondary. And that's really confusing and difficult because it does mean that whatever we do, you still have to either treat what you're seeing and assess the clinical effects and repeat the tests. And bear in mind that many diseases may wax and wane, and that can really throw the interpretation of clinical response out.

Or we kind of have to test for PTD anyway. So it's one of the differentials of dilated proventicular. It makes some degree of sense that we have to test for it alongside all the other differentials, so we have to test for that.

So how do we test for that? Well, OK, back to our rule out. We do have to rule out other causes perpendicular changes and treat those and see what happens.

That is part and parcel of it. The old fashioned way is to biopsy gold standard is to biopsy the proventry. And take a section there and we're looking for the nerves and the complex is there and you're gonna see what, what, what comes through that.

However, this is a typical PDD stomach. It's really thin walled. If you start to cut into it, it's going to tear and rip it and fall apart.

So biopsying a PDD case is really, I mean, biopsying the stomach anyway in a bird is, is, is quite dangerous. It's not to be undertaken lightly. Doing a PDD stomach is so thin walled, it is really dangerous and unlikely to close it, which, yes, OK, fine, may confirm your finding the time, but it's not going to be compatible with the bird surviving the test.

And so that's a bad way to go. So most people who are doing biopsy will biopsy the crop, and when we take the open the crop, it's very easy surgery and gluviotomy. It's very easy to take a biopsy, it's very easy to close and survival rate is, is massive, and, and very rarely do you get complications.

When you do it, you do the opposite to what to what seems normal. You actually look for a blood vessel in the crop wall and you take a section with that because we all remember our anatomic artery vein nerve, they run together and you're looking for a nerve to see whether you got the inflammatory infiltrates within that nerve. So that's what you're trying to do.

So you take one. The only problem is with that is it's only about 2/3 diagnostic, which is not a very good success rate for a diagnostic. So what we'll probably do rather than that now is probably do ABV testing.

And for ABV testing, we do serology and PCR. The PCR is done on a combined crop and cloacal swab, swab the crop, swab of cloaca, and that combined plane swab into the lab for PCR and serology as well. And we need both because very often at the time of disease, they're not shedding virus, so PCR is often negative.

And some spec of birds don't seem to convert very well. So hopefully one or the other will come up. So you do need both tests in there.

OK. So let's say we get a positive serology. And positive serology is, especially with clinical signs, is diagnostic.

It's not just increasing this suspicion, we'd say that's diagnostic. So positive PCR or positive serology or both, then we're really diagnosing PDD, especially with, with clinical signs of fit. So what's our therapy?

Well, bear in mind that the disease is really, associated with malnutrition, so we want to change, we do some dietary stuff. We'll often be feeding, a rearing diet, which is gonna be highly digestible, often semi-liquid, which, which is going to be fed and many of these birds are hand red, so it's often easy to get into them, but a really rich, easy digestible diet makes a lot of sense. There has been a little bit of work done many years ago using Celle coxi, which is one of these, cos, sparing, anti-inflammatories, and that showed, good success rate.

It's unclear how much repeated that's been. And what is interesting is other NSAIDs do not seem to show similar effects, and studies on meloxicam really show absolutely no effect whatsoever on this. So I think the jury is out on NSAID, in my experience, it, Doesn't seem to make a lot of difference in most cases.

It might make a difference in some cases. If it increases confidence to use diet, diet and, and, and improved digestion from that, then that may be good enough. But just bear in mind, it's not the answer to everything.

There been a little bit of trial work using cyclosporin, again, patchy results, and, you know, maybe, just something to keep, keep your eye on. Cyclopor can be associated with other side effects and does seem to be highly variable in dose between different species. If you're going to use it, do check out the dose rate in that species of parrot.

And of course, if it's a really severely affected bird, this is a viral problem, this is a reaction to the virus, really, you, you may be justified, you probably will be justified offering euthanasia. And in some cases, that's absolutely essential because the bird's welfare is severely compromised. So it brings down the questions too.

If you dying from PDD, you know how infectious is it? It is an infection. It's linked to a virus.

So what are you going to do with contact birds. It's a really weird infection. A lot of clinical signs are really down to the body's response to the virus rather than the virus itself.

And there's plenty of case reports where you've got two birds living together for, for goodness how many years. One is diagnosed with borne virus and confirmed, and the other bird is coming up to every single test for it. It doesn't seem to have got that.

And that may be linked into how it appears to be transmitted. It may be linked into bodies respond to it, and some birds can kick it out and just get rid of it. And some birds, form this really weird immune response and and get neuropathy.

So we can do that in contact birds. Well, probably it'd be a sensible idea to test them. But again, Even if you get negative results, regardless potentially as having been contaminated and be very wary about mixing new birds with them, that might be quite useful.

Certainly there's no reason to do a full scale clear out of all the birds unless you may be a really weird, a situation that might be most want to consider in those cases too. And in collections. Again, it can be very odd.

We see this case with single cases and long-term cohabiting birds not affected. And yet in times, we can see PDD enter an aviary and just cause a mass mortality situation. And my experience that seems to be more coners than anything else, but that, that, that's just, you know, it's a very subjective view.

It's pretty important in a vet clinic, what you can do about wards because probably do investigation, treatment, probably been hospitalising these birds for a while. And certainly probably routine cleaning, routine disinfection will probably be sufficient, within this, but again, probably watch your space and see what's there. And certainly, if it's, you know, less, not so infectious, that might be to our advantage.

Trouble too is, of course, many of these tests take a long time to come back results, and we may have been using our, our hospitalisation facilities for other birds in the meantime. But certainly if you have a suspect case, it probably makes sense to rest the cage, to deep cleaning, and, and, and reduce a chance of contamination. There's some talk too about the fact that when they actually show clinical signs, they're less infectious than before that, which makes life even more difficult where we we're screening and clearing.

But again, I think probably subject to, a lot of opinion there as much as fact, and there's a lot of active research into that too. But again, I always considered pathophysiology is that basically this is fundamentally a disease of the immune reaction to the virus rather than just the virus itself. In terms of screening and again with an aviary and some pet boards often want to be screening for this too, .

It's a difficult one to know what to, what to recommend. We can do serology, we can do PCRs. Again, ideally, we should do both.

Obviously, for screening, that's gonna really increase expenses and not cheap tests. We are going to get false negatives and to my mind, if we're doing screening, particularly into like boarding facilities and stuff, that doesn't make this a very safe thing to do. Especially as we may be missing potential causes.

Some of these may not be borna virus and maybe other things that we as yet unknown causing this because certainly you get a lot of cases that really do appear to be PDD but come up negative to Borna, which may be a function of testing. It may be a function of what else is going on there. Certainly one thing I would recommend is that if you've got a connection, if you've got boarding, that every bird going into those should have a full clinic examination and in particular assessed body condition before you go in there.

And thin birds, should be investigated. Again, to even just do a basic proven trick to check before we go and mix other birds and see what else might be going on. Hygiene also appears to be really important, and that's because some of the latest research coming out and looking at how these birds are getting affected.

It appears to be quite hard to affect birds via the oral route. But the most convincing results so far appear to be indicating this might be due to ascending neuropathy, where viruses entering from dirty perches into foot wounds and then tracking up nerves into the central nervous system into other parts of the body. And that there's very early days, and again, this is definitely not gospel at the moment, but certainly some research seems to be indicating this can and could well do.

And that can answer a lot of questions about why. You know, neighbouring birds, cohabiting birds don't seem to get this. What it appears to be quite hard to transmit and get.

That also is very helpful. That is the case that we have a clear route of preventing spread between birds as well. The hygiene is so important too.

Nonetheless, hygiene is a great thing to do. So cleaning is, is definitely next to godliness of a veining practise. With our wards, we can keep things clean.

We can disinfect, we can remove that viral load from there, even if the next parrot into that back cage could be one who does have a foot wound. So that's really important. So in summary, PDD is probably the most common cine infection disease at present.

We certainly see far more of it than we do even of chlamydiosis. It is really hard to diagnose. I think you got that impression by now.

And this clinical signs are not pass the mnemonic. So if you do have a diary perventricular, bear in mind other things cause that rather than write this down as being a viral problem. It is also poorly understood at present.

I mean there's a lot of research going onto this. Every avian conference produces more research. We're getting better and better, but it is really poorly understood.

And certainly the treatments and management techniques are really poorly understood. And there's not much known about that and not many options there too. So the big deal is watch your space and if you're treating a lot of parrots, keep up to date with the latest research because it does, does, does, it is increasing year on year.

Thank you very much. And Everything I'll get back to watching the World Cup semifinal. Fingers crossed it's going well.

Hopefully, hopefully it is. So thank you very much, John, for that really informative talk. I'm just gonna open up, if anyone has any questions, if you can tap out, you can type it away on to the question, question and answer section, and we'll just give you a a little minute and just see if there's any questions you want to come through.

So while we're waiting for this, I'll just take this opportunity to remind everyone, not to forget to join us next Tuesday on the 9th of July at 8 o'clock. And that will be for the second webinar in this exotic series, and the next week's one is the . Teeth.

Is it worth the expense in exotics and small mammals? So it doesn't look like we've got any questions coming through at the moment, John. So what I would like to do is just thank you very thank you again for a really informative talk.

I think you probably answered everyone's questions already. So yeah, yeah, so I think we will, we can end the session here. Oh, I think, yeah, yeah, I did, very informative.

Thank you very much. Thanks.