Hi. And welcome to this Webinar where we're going to be looking at feline infectious peritonitis. So there's been loads of exciting developments, that we've had, over the past couple of years and new drugs available and a new one, actually, just this year as well.
So there's definitely a lot to talk about, kind of, treatment options and also the, current recommendation, which are updated fairly regularly as we get more experience and more knowledge of, this disease. But I think it's also important that we kind of go back a bit to the pathophysiology and the diagnosis because we can't treat these cases without us having, a good knowledge of, what can, kind of occur. And most of the these cases, we will have, you know, a lot of, information and, trying to be making a presumptive diagnosis because it's very hard to, get a definitive diagnosis.
But some cases we may need to consider a treatment trial if we're kind of hitting a brick wall with our, diagnostics. So the diagnostics definitely play quite a key role. So first of all, we need to think about What is F IP and F IP is, an enveloped RN, a virus.
So we have feline infectious peritonitis, viruses, and those are the viruses which cause, F IP. And then we have feline enteric coronaviruses. And those are the viruses which cause sometimes enteritis, But often they just show no signs of ill health.
And it's very important that we kind of, I suppose, differentiate the two because a lot of cats will be exposed to coronavirus, and they will be, positive. So, for example, if you did faecal sample for coronavirus or if you did, serology so they may have antibodies. But that does not mean that they've got F IP and those sort of, testings for the kind of just the, PC R in the faeces or for the serology for the antibodies are not useful for diagnosis.
But we'll come on to that in a bit more detail. So we know that in the General pop, cat population, about 1% will, die of, F IP. But we know that feline coronavirus.
kind of positivity. So where they have serology? We'll be thinking about, 10 to 50% in a single cat household will be positive.
When we look at kind of a multi catt household, about 80 to 90% of them will be, Freel coronavirus positive. And about 5 to 10% will die. Of F IP.
So there's different, serotypes for, F IP. So we've got, serotype one and sero type two. And type two is similar to canine coronavirus, and it's thought to have evolved by merging of feline coronavirus and canine coronavirus.
And most infections are type one and type two, we think may possibly be, a little bit more potent. So when we look at the coronavirus infections, often we don't really have any clinical signs. So in most cases, these patients are gonna be, asymptomatic when they are shedding, coronavirus.
We can get kind of low grade G I infections. They sometimes get diarrhoea and vomiting, but it's usually kind of self-limiting, and it's not something that we would go and treat. Occasionally, we might see sneezing, and we might also see, upper respiratory signs as well.
So F IP infections is different. So we've obviously got the coronavirus, but we haven't got this more kind of benign enteric coronavirus. So in this case, the coronavirus mutates, and that can happen in both type one and type two.
And this allows the virus to, leave a gut and spread through many tissues in the macrophages. And it's seen in kind of all tissues within about 14 days, and it can go anywhere. And this is really important for understanding, kind of the different, pathogenesis of the disease.
Because with F IP infections, it really can present with pretty much anything so we can see that this disease can go, for example, to the liver, spleen, lymph nodes, the CNS. So if we're thinking about an individual cat, then we may think see things, for example, like, enlarged lymph nodes. We may see things like seizures.
And we may have kind of neurological, deficits. And it all depends where the, infection is going. And it's also important to try and differentiate what sort of infection this has.
So does it have the dry form? So that's where there's no, fluid building up But we might have, for example, lymphadenopathy. Or we might have some abnormal irregular, kidneys.
Or does our patient have, neurological involvement? So, you know, with, neurological, deficits, abnormal mentation potentially, seizures. And the reason that those are important to differentiate kind of the dry form, the ocular form, the neurological form and the wet form.
So where there's effusions is because we do treat these with, different doses of the drugs. So, we need to know kind of what type of, F IP. The cat has so we can kind of substage them.
So we see coronavirus mutations, and I suppose we still don't know exactly why we, have them. So if we looked at the, percentages that we had, for example, the kind of general cat population and then single cat households and multi Catt households, we know that, feline infectious peritonitis is more common in multi catt households, and it's also more common, in certain, pure breeds as well, and in kind of breeding, colonies. So there's definitely a factor of, kind of, households where we have, increased, replication of this, virus and an increased, viral load.
So just by, simply having, more animals there. We also know that it happens particularly in, younger animals. So a lot of our animals are gonna be kind of less than a year, of age when they're affected.
And we also, think that there's a genetic predisposition. So it's definitely more common in poor breeds. And well, we definitely see it with, increased prevalence in certain breeds.
For example, the British short hair. So there probably is some, genetics, that is also, playing a role. We also know that kind of stress can definitely, cause, precipitation of, signs as well.
So, for example, if an animal has recently been rehomed or if it's just had a nutrient procedure, then, that can definitely affect it. So we think that kind of the immune status is also going to, affect whether these, mutations occur and whether F IP, does develop so as well as looking at kind of stress and surgery. We also need to think about if the patient's got different, infections concurrently, or if there's any stress, and we also know that not all of the viruses are the same.
So there may be different virulence in the viruses, and you may have all heard about the outbreak in Cyprus. So that was a particularly scary, variant. So usually the mutated form of coronavirus doesn't pass from, cat to cat.
But in Cyprus, it was, doing exactly that. So they had, you know, thousands of cats that were, dying, as a result of, F IP. So when we look at the, pathogenesis, we kind of the exact mechanism isn't known, but we know that there are kind of antigen, antibody complexes.
And we also have, these, infected macrophages, which will also attract the, antibodies, as well. And what this can do is this can then, lead to, complement, fixation, endothelial cell retraction and increased vascular permeability so we can get leakage of our plasma proteins. And that's where we see kind of a classic wet form where we get these effusions and the effusions, are most commonly in the abdomen, and also in the pleural cavity.
But we can see them in other, places as well. So for example, they can get kind of pericardial fusions associated. With this.
So when we look at F IP, transmission. So this is, I suppose, more coronavirus transmission rather than actual F IP. So this is the, FO oral route.
So we know that, coronavirus can shed and can persist for, many weeks. But usually we have no, of the infection, and it's readily inactivated by detergents and disinfectants. So the F IP, mutated form usually doesn't, be transmitted from one cat to another.
But the coronavirus that they will have been exposed to initially can transmit from one cat to another. So the host immune response is really important. When we're thinking about which cats, develop, F IP.
So we know that, we can have wet and dry forms, and then we also have these subsets with ocular and neurological as well, and generally, when we're looking at it, if we've got a weak cell mediated immunity, the cat's more likely to have a wet form with a partial cell mediated immunity. That's a dry form and a strong cell mediated immunity. The cat is, hopefully going to be, healthy for that.
So the immune status is definitely playing. Quite a big role for, for how these cats are, presenting. So I think, as we can see with F IP, it's definitely multifactorial.
So they obviously have to be exposed. And if they're in kind of multi catt households and breed and environments and they're much more likely, to be, exposed to the coronavirus, if they've got the right genetics, so I mean particularly certain breeds. That may be, predisposed.
Then they're also more likely to, develop if they've had a history of stress or surgery. And if they have this, kind of poorer, cell mediated immunity as well, Then that may also be playing a role. So when we look at dry F IP, this one can be particularly difficult to, diagnose.
With this one, we see development of, granulomas and overproduction of proinflammatory cytokines. So particularly, tumour necrosis factor alpha and interleukin one beta. We can get a systemic activation of neutrophils, and we can get granulomas developing throughout the body.
So why this can be more difficult to, diagnose Is that, you know, if we, for example, have this in the brain, that's causing, signs, you know, not O. All owners are gonna be able to, be thinking about doing MRI and potentially spinal taps if that is safe to do so. And there's no increased intracranial pressure.
The other problem is that we may get these granulomas presented, for example, in the kidneys. And not everybody is going to be, necessarily happy sticking a needle in the kidney to, try and diag. Nose, this as well.
And also, the diagnosis can be a bit more problematic, so we'll come on to that as well. But it's much easier if we've got kind of fluid present. So with the kind of wet forms, it's much easier for us to get a sample and do the, necessary tests on that.
So, with dry F IP, you know the clinical signs are gonna be so variable. And as we said, this infection can really happen pretty much anywhere. And the signs that we're going to, see are going to depend on the tissue affected.
So if we have particularly abdominal organs. So, you know, gastrointestinal tract liver, and things like that we might see diarrhoea and weight loss and vomiting. The eyes are really important place to look in all cats.
I think generally, in all cats, to be honest, So, but particularly in cats where you suspect to have, F IP then I'd strongly recommend doing a retinal exam and AJ good ocular, examination Things that we may see are things like uveitis we may see hyphema and we can also see See retinal detachment if the, F IP is affecting the, CNS. Then we can see ataxia seizures, behavioural changes and, neural, deficits as well. If it's affecting the liver with granulomas, then we can see jaundice and and weight loss.
And in the kidneys we can see Reno megaly and often kind of this irregular, outline to the, kidneys. And the cats may be, Aso and have renal insufficiency. As a result of that as well.
So these are just some images of a cat with, FOP, affecting the kidneys so you can see these granulomas. So you can kind of imagine that if you were to palpate this cat, it would have very regular, outline of the kidneys, and may also have Ren omega as a result of the granulomas present. So we IFI P is, seen where we get kind of that inflammation of the, blood vessels.
And we get kind of leakage of this high protein fluid in the body cavities. And this image is a cat. With, kind of typical F IP where we see this kind of yellow, fluid, being produced.
And often it can be frothy as well. Just with the high, protein content that we can see so we can see pleural effusion ascites. And we can see pericardial effusion, as well.
And when we're looking at this, under the microscope, we can see, lots of macrophages and non degenerate neutrophils, as we can see in this cytology image on the bottom, right. It's also important to recognise that although we call, you know, wet IFI P and dry F IP. The forms aren't mutually exclusive.
So you could have a cat, for example, with, granulomas on the kidneys, but also having ascites as well. So when we look at, F IP, it's, most common to get, effusion within the abdomen. So ascites is seen as about 62% of cases and, pleural effusion in about 17%.
And we can see both, bry effusions so effusions in the abdomen and the thorax in about 21% of, cats as well. So you can see in this, image. Here on the bottom left.
This is a cat with, pleural effusion where we're, draining, the chest and doing thoracocentesis. And then we've got a cat on the right, which has kind of marked abdominal distention. And this is a cat with, F IP.
When in the web form due to significant, abdominal effusion. As I said, we can also occasionally see fluid, around the heart as well. And it's important to recognise that you kind of with cats with effusions about less than 50% have F IP so we definitely need to have it on our diagnostic list.
But we need to not remember about other things that can cause effusion. So, for example, congestive heart failure, and hyper Albania and things like that that could also cause it so as a diagnosis can be, problematic, anti mortem. So when we're looking at the gold standard, that would be looking at immuno chemistry on biopsy samples.
But, you know, taking account with, F IP that's already probably very ill anaesthetizing it and doing biopsies might not be the best thing for it. So I think it's really important that we kind of don't just go down the road of, definitely wanting to get a definitive diagnosis in all of these cases. And sometimes we are going to have to make a presumptive diagnosis, and that can be made based on kind of the signal.
So, you know, if you have a young cat, particularly a purebred cat, one with a history of kind of stress surgery, multi catt household, you know, that's kind of ticking more boxes, clinical findings, which will come on to so particularly things like hyperglobulinemia hyper Albania hyperbilirubinemia and, kind of ascites and things as well. And if there's kind of analysis of effusion, then that can be really helpful. So this is, a cat where you can see again this typical straw coloured fluid.
And this is absolutely great for us to do kind of, cytology and and PC R and basically trying to rule in F IP, but also ruling out other differential, diagnoses. So history is really important. So, you know, I think, I was always taught, you know, with history and clinical exam.
That's the one bit that the owners, have already paid for. So, you know, they've already paid for your, consultation. So definitely make the most of, kind of this free, information that we may have.
So when we're looking at the history, then we may have a proceeding. Stressful offence. So the animal may have been adopted.
It may have, just been recently neutered and had surgery, but it's important to remember that these animals may have non-specific signs. And I think this is what I love about feline medicine is you know, no matter what, our cats ultimately get diagnosed with a lot of the time they'll be going off their food, and they might be more lethargic. So it's important that we, remember that, you know, kind of these vague signs should definitely not be, ignored, but it can make diagnosis a little bit more difficult.
One of the things that we do see across all of the studies is that these, cats can have a pyrexia which can be unresponsive to antibiotics and also non steroidals as well. And the pyrexia can be marked. So, you know, we can easily get pyrexes of, like, 40 degrees.
These cats can also have ocular lesions. So, you know, I'd really encourage, as many people as possible to be thinking about doing a good ocular exam. We may see things like uveitis hyphema, aqueous flare, meiosis and Katic precipitates.
So it's really important that we have kind of a thorough ocular exam. So when we're doing, kind of further investigations, we definitely want to be doing kind of our haematology and our serum biochemistry, But we're not going to be able to diagnose based on, this, but you know This is all, I suppose, with F IP. It's part of the picture of kind of a tick box exercise.
You know, Does the history fit does the signal, But does the clinical and pathological signs fit? And then if we've got the, the, benefit of having kind of fluid or cytology or biopsy, then that's, absolutely, great to try and get, a diagnosis. So haematology is obviously really important.
For this and we can see a few things, so we commonly see, lymphopenia. And we can see, anaemia as well. So lymphopenia is obviously non-specific, and it can just be seen as part of the stress response.
So it's not something that we're going to diagnose, on the basis of, of that, but it's something that we can see. Anaemia can be a bit more, significant, because although, we often see kind of a nomos of anaemia and anaemia of chronic disease. Some of these cats can get a significant, anaemia, which may be secondary to I MH a so, so these cats can get like an I MH a so kind of a new mediated hemolytic anaemia due to their, F IP.
So that is rarer, but it's something that we need to bear in mind. So with those, we, we usually get kind of a regenerative anaemia, and the anaemia can be, pretty, severe. The thing that we do need to bear in mind, though, is that often these cats are young, so, you know, often they are kittens, and we know that their hematocrit will run, lower than an adult, anyway.
So if we are comparing, their haematology to adult reference ranges, then we need to kind of, account for this and recognise that just because of their age, they might have a lower, hematocrit, so biochemistry can help us a little bit more. With this. So, a lot of these cats will have an increased level of their globulin.
So they have this profound, inflammation. And, you know, secondary to the infection and inflammation that can lead to an increase in our, globulins. If we were to do, serum protein electrophoresis.
So that basically looks at our proteins a bit more closely, and it says Is it polyclonal so due to like infection or inflammation or is it monoclonal, which is more commonly due to neoplasia, particularly lymphoma or multiple myeloma? And if we did serum protein electrophoresis, then we'd expect the vast majority of these, if not all, to have a polyclonal, goopy as well as having, a high level of globulins. We often see a low level of albumin.
And when we do the ratio of the albumin to globulin ratio, if it's less than 0.4 then that can definitely raise our suspicion. Of F IP.
We can also see high levels of, bilirubin, so you can see this cat on the right. That is icterus. So this is a jaundice cat, and we think that can be due to increased, tumour necrosis factor alpha.
So these proinflammatory cytokines. And it could also be secondary to, hepatic granulomas, but particularly if we see you know no signs of kind of liver disease or liver involvement. If we see this hyper Albania in a cat, we do need to be thinking about F IP as well as other differentials such as sepsis as well.
So alpha one glycoprotein can, be something else that can be, useful to measure. So some of the kind of F IP profiles, laboratories will include this, in there. So this is an acute face, protein.
So this is just measured on, serum. So if we have a high pre-test probability so a cat that is fit in the clinical sign. So, you know, we've got a British short hair.
It's a young cat in a multi catt household. It's icterus. It's got oar, signs.
So, like a U Vitis, then, an a GP of 1.5 to 2 MiGs. Per mil is kind of supportive if we've got a lower pret test probability.
So, you know, an older cat not showing all of the typical signs, Then more than three MiGs per mil is going to be supportive. So, again, this none of this is going to diagnose, F IP for sure. But with these changes on the kind of clinical exam, history, signal and biochemistry, we can be putting together quite a nice picture.
To see what? What, disease may be, occurring. So if we've got an effusion.
We definitely wanna take a sample, and we don't really need to take that much of it. We just need to have enough to, do cytology and potentially PC R. And if there's any concerns about sepsis, then we want to also be doing, culture to rule that out.
And the reason that we also, you know, definitely want all of these, tests on effusions is because they have a much higher diagnostic, value. So when we're looking at the effusions, we often get this kind of yellow sticky, fluid with a high protein, content so usually more than 35 grammes per litre and a low cellular contact, content. So less than 5000 cells.
And when we're doing cytology, the typical one we see is, this image on the right. So it's P graeters inflammation. So we get macrophages and non degenerate neutrophils and a few lymphocytes.
So if you're presented, you know a cat with an abdominal effusion. You know your main things for that is the main differentials is does this cat have hyperemia, which you would be able to see on? Your, blood work.
You know, in typically it has to be kind of less than 15 grammes per litre for that to be causing the, effusion does it? Congestive heart failure. So, you know, a quick, T fast and doing the left, atrium to aortic ratio will help with that.
Does this cat have, lymphoma? So cytology would be able to hopefully rule that out? Does it have a septic effusion?
And again, cytology Would, rule that out? Or could it be, for example, portal hypertension, which you would need to have more imaging for? But just having this analysis on the effusion, not only can this help us to, diagnose, F IP, but it can also rule out other differentials.
So, you know, particularly with progest of heart failure, it's usually a kind of a trans date and the same with hyper Albania. So that would make it less likely if we're not seeing degenerate, neutrophils with inter cellar bacteria. There's no evidence of sepsis.
I mean, if we're not seeing lymphoblasts, then there's no evidence of lymphoma, so definitely if you've got any effusion, have a look at it, and send it off for analysis. And there's also other tests we can do on the effusion which will come on to with, PC RS. So valta test is kind of quite a crude, test And I have to say it's something that I used to do more, when I was working at a university setting with, students rather than in in practise.
But really, what it's looking at is, kind of seeing with the, effusion kind of the looking at the protein content in it in particular. So the sensitivity is about 91% but it's not great specificity. So, you know, with this, we can also see an increased in septic persis and lymphoma, which are gonna be two of our main differentials.
So it's definitely something that we can easily do in practise. So we just have seven mils of distilled water into a plastic test tube and add one drop of 100% acetic acid and then place one drop of, effusion, and it's positive if the drop stays attached to the surface, retains shape or slowly floats to the bottom. But you know as it with these kind of false, positives.
We wouldn't want to rely just on this. We would definitely want to do cytology over a revolta test. So I think it's important that we look at kind of the feline coronavirus antibodies because this is something that is commonly measured, and all it's showing is, exposure.
So for me, measurement is not helpful. Most cats will have antibodies present because coronavirus is so prevalent in the environment. And when we look at previous studies, there's no difference in the median tighter concentration in our healthy versus our F IP cats.
And it's also important to remember that if we don't have antibodies, that doesn't exclude the disease. So about 10% will be negative. And this is especially more in kind of end stage disease and in the wet form where we've got large amounts of virus binding the antibodies and where antibodies can be lost into the effusion.
So although it can be helpful, so so so for most cases, it is not helpful. So with freelance, coronavirus antibodies, it's something that, personally I just do not measure. So what can be more specific is looking at immuno histochemistry, immunofluorescence and Immunocytochemistry.
So immuno histochemistry is doing to detect the Phelan coronavirus antigen in macrophages in tissue. So that obviously needs biopsies. Or we can be looking at in fluid or on, Cytology.
So, for example, of FNAs of the kidneys where we're doing like immunocytochemistry so immuno to chemistry can definitely confirm the diagnosis with immunofluorescence and immunocytochemistry, we can get false negatives. So particularly if there's low cellularity then we have, then it can be negative and the antigen can also be masked by the antibodies. We can also see false positives.
So, although, it's not as common. There are studies which have shown that we can see it both with immunofluorescence and immunocyte to chemistry. So we can also do RT PC R and that's looking at the coronavirus kind of like DNA, which can be performed on fluids or FN a of the affected organs.
It's not something I would do on the blood. We can also do quantitative. So where we get AC T value and that will be helpful as higher viral loads are gonna be more suggestive of F IP.
So when we're looking at tissue samples, about 90% of F IP cats are positive, but we can also see some false positive. So about 7.8 in non F IP cases, effusion samples can also be used, and they have a high sensitivity and specificity.
So when we're looking at effusions, about 72 to 100% of effusions from cats with F IP are gonna be RT PC R positive, and we get a low number of false positives. So when we looked at, lymph node aspirates from cats with dry F IP, 90% of these were positive and there was one false positive CS F, can also be good, but, it has a lower, sensitivity. So anywhere between about 21 to 86% of those were positive, and we can see that it's got a good specificity because it was negative in all control.
Cats in one study, looking at detection of aqueous free and coronavirus and aqueous humour with F IP is poor. So although we can do kind of, I suppose, at specialist level doing aqueous Andes, we know that in these cases, we may have, cases which are just gonna be falsely negative. So, with these ones, we're only gonna detect it in about 25% of, cases we can do PC R on, faeces.
And that's only really useful to detect shedders. And it's not gonna help with diagnosis. So it's just like with the antibodies.
So with the antibodies, we can see that, you know, they have exposure to it, and we know that a lot of cats can shed F IP. Sorry can shed coronavirus, but that does not equate to, F IP. So, with this, you know, I wouldn't even do a faecal test.
For coronavirus, PC R in a cat that I suspected to have F IP so quantitative. PC R can be, really, helpful. And usually what that's documented is AC T.
So the cycle, threshold and a low CT is gonna mean a higher number of the virus. So, with, infection with coronavirus, most cats will develop a, via even if they have kind of a normal coronavirus. So it is possible that cats without F IP can have detectable virus within blood effusions and tissues.
And that's why we see the false positives in some of these, cases. But, usually they're at a lower level. So that's where the quantitative, PC RS can, definitely, be helpful.
So if you haven't already, had a look at, the ABC D. So this is the advisory board on cat diseases website, then definitely. Take a look.
For, F IP. So they've got lots of these kind of diagnostic. Approaches.
So this is kind of for the, wet form and the the dry form. So again, it's doing exactly what we've kind of discussed. So if you've got the effusion, think about the RT PC R and potentially immunocyte chemistry.
And if it's positive, then obviously, it's going to be, very likely. And the reason they don't say it's completely confirmed is just because we know that there can be a small numbers of, false positives, but they have nice algorithms of what to do next. If, you know that that's not, positive.
And, you know, if we're still suspicious, then, for example, sampling, accessible, organs. So now we can come on to kind of the treatment. And, when we're looking at kind of historical, treatment for F IP.
We know that previously it was a univers fatal disease. So in studies where the cats definitely had F IP so where they could completely confirm it, Then the median survival was about nine days. One cat did survive 200 days, and what we knew previously is a kind of prog negative prognostic.
Indicators were kind of poor body condition, low platelet counts, low lymphocyte counts, high levels of bilirubin and larger fusion. So if we look at some of the oldest, studies as well, you know, they were looking at things like feline interfere on, Omega. And with these cats, you know, they just found absolutely no effect on, survival time or quality of life.
So this was the, groups where they were either given a placebo or given feline interferon, and we can see that the survival is pretty awful. So there was one cat that survived 200 days, but This was a study where the median survival time was eight days. So it was really, you know, quite, a horrific disease for both vets owners and their, cats as well.
There was also studies looking at, propylene. So, to see whether this could, particularly, help. And again, there wasn't really any effect on their survival, quality of life or clinical or lab features with this feline.
polyopia immunos stimulant. Kind of had the longest reported survival time of, cats with F IP. And, in this study, they were looking at cats with, Tri F IP.
And they found that, eight cats survived over 200 days, and four of them survived over, 300 days. So this was kind of the longest, time that we, had, so this one was showing some, improvement. But then we came on to kind of newer treatment options, and these were some of the first studies looking at, GS 441524.
So this is an antiviral, drug, which works against RN A viruses. And it's a pro drug for Rem Devi, which is GS 5734. And it works by inhibiting virus replication by acting as an alternative substitute and RN a chain terminator of the viral RN a polymerase.
So basically what it does is it interferes with the coronavirus, replication. So in the, first, study, that was, looking at this. They had 26 cats with the wet form and five with the dry form, and they were treating them with 2 to 4 megs per kig, once a day for at least 12 weeks.
And 26 of the, 31 cats completed the 12 weeks of treatment. So with this, they, had or they tried to make it kind of as robust as possible in this study. So these cats were diagnosed, based on RT PC R or immuno histochemistry.
Ideally, but they wasn't essential for inclusion. And I think that's also reflecting the way that we have to do this in practise because we're not always gonna be able to try and get a definitive, diagnosis in this initial study. They didn't do, any counts with obvious ole or neurological signs because they were concerned about the ability of the antiviral drugs to penetrate the blood brain barrier.
But we know now that we can use these at higher doses for those, signs. So this was the, first study that was published in 2019 by, Nils Petersen. And this was a kind of like, absolutely amazing, results.
So this had 25 kind of long term, survivors in this, study. So out of the 26 cats, that kind of, completed the 12 weeks 25 were then long term survivors, and one of them, was then, successfully treated, but died of an unrelated heart disease. And 24 of them remained healthy, for months down the line.
So this was kind of a total game changer, in F IP, treatment. So they found that the pexy resolved really quickly. So usually within a day, appetite, activity and weight improved, and the abdominal and thoracic effusions disappeared, and icterus and ocular signs resolved, and they found that two after two weeks, the cats appeared normal with 25 out of 26 having a sustained remission.
So they then went on to do another study, looking at it in neurological, disease as well. And in their studies, they had, four cats which were treated for, at least, 12 weeks. So, these again showed that, they had long term resolution.
So one of the cats were euthanized after 200 16, days after they had, relapse. And, one case had resolution, of the, disease, which they could confirm on MRI and, CS F. For those.
So there's also studies looking at, suspected, F IP. And, with, cases which were being treated with, GS 441524 or GC 376 and out of 30 cats treated, 29 of them were clinically cured. So, you know, there's lots of, information that was coming out.
We know that there are also, black market drugs. And I think it's important to mention these, we're seeing less and less cats, owners, using this, But there are still some that will, be seeking out, drugs from online forums. And there is kind of this large online market, thankfully, not so much in the UK because we have these licenced products.
But there are still countries where they are, able to, import these, drugs. It's illegal for both owners and vets to obtain these medications. And it's unknown what these medications contain.
And there's been reports of, contamination. So, you know, we really don't want to be using these, medications. And there's no reason at all, really, for, for using it in the UK.
It's also expensive, and we know that the treatment for F IP is expensive. Anyway, but these, drugs, you know, have the same sort of, prices. So there have been studies which have shown that these unlicensed, drugs can be, effective.
But I think one of the things that was particularly scary in this, study was only 8.7% of owners reported receiving significant help from their vets. And it's very difficult for vets because, obviously, you know, we can't be, advocating or, advocating any of this, use.
So it's very difficult for us, to be involved. But it does mean that, you know, you've got potentially very sick cats where owners are getting their information online. So there are some, studies, which we're looking at kind of these, analogues as well.
So this was, one, which was min so one of the more common, kind of illegal drugs, which shows that it it definitely, can work, in these cases, but it's definitely not one that we would recommend. The other thing to bear in mind is that this was a study. That was done in 2024 where they were looking at the unlicensed anti viral products.
Which owners were, procuring, online. And then if you look at this as well, they So they had 30 of the most popular brands. So, you know, there's so many of them just flooding, the market.
And they found that, in the injectable formulations, 95% contained more GS than expected, and the PH was well below the PH recommended for sub QE injections. So that can definitely lead to, you know, pain and, potentially irritation of the skins in the oral formulation. They found that, in some cases, 43% contained more GS than expected and 58% contained less.
So you really don't know what you are, treating with. And this was also important because there is a, a study looking at, two cats which developed Elis and they were receiving these unlicensed, GS 441524 products. And they developed Ural lists which were composed purely of this, GS, substance.
And that's not something that has been, seen with the legal products. So, I was involved in this, study, which was looking at, the, outcome of 307 cats with F IP treated with the legally sourced, products. And with this, we found that, the, outcome was exceptionally, good.
So, when we were following, these cats up 84.4% of these cats were still alive. And they, seem to be in, remission as well.
So there's lots of other studies, going on at the moment so that we can, try and look at even longer term, survival as well. Of these, cats. So in the legal, treatment options in the UK, we've got three different.
So we've got remdesivir as an injection. We've got GS 441524 both as tablets and an oral suspension. And we've got E.
I, DD 19 7, 1931 which is as an oral tablet. So Remdesivir is a pro drug of GS 441524. And, Gilead, the, initial company, who make this?
They had, remdesivir available to vets as something called vetle. And then, since August 2021 a special manufacturers in the UK have made injectable remdesivir available to vets. And this is, kind of even better than the Gilead formulation, because it's a higher concentration.
So we've got smaller volumes. It's got a preservative. So it has a longer shelf life.
And it may be, less painful. So we're legally able to treat these, cats with these, products. GS 441524 has been available since November 2021 and it's also been legally available in Australia.
For, for the same time, For sorry to proceed in a few months, for that as well. So previous research papers were primarily focused on injectable forms. And based on kind of experience, we now have, oral, protocols.
And we recommend kind of giving this on kind of an empty stomach or with a small treat. But obviously, if they're kittens and we're not going to starve them. So the new protocols which we're doing, the vast majority of, these cases will have oral GS 441524 alone.
So some cases will transition from inject four rem Devere to Oral GS. 441524 and very, very few. I mean, I can't think of any at the moment that have had the full 12 week course of injectable.
So although it's possible, we don't really do that, there's some where we need to give them injectable rem de severe at the beginning. And that's particularly for kind of severe neurological cases. If we've got severe dehydration or illness or if we've got dysphagic cats or we're unable to orally medicate them.
And as time has gone on, we have been increasing the, dosages, from, previous, recommendations. As we're having more, experience. So with the new dose in recommendations, if we have effusions but no ocular or neurological signs, then we're doing 15 megs per kig once a day or split and, twice a day for GS.
441524 if they have the dry form, with no ocular or neurological signs and it is the same If we've got ocular signs present, it doesn't matter if that's then dry or wet form. Then we're doing 15 to 20 MiGs per kig every 24 hours or split every 12 hours. And if we've got neurological signs present, then it's 10 megs per kig twice a day.
If we do need to start with remdesivir, then if we've got the, effusions so wet forms, but no ole or neurological signs and we do 10 to 15 mgs per kig once a day. If we've got, a dry form with no ocular or neurological signs, and it's 12 to 15 megs per kig once a day. Ocular signs.
We go up to 15 megs per kig once a day. And any neurological signs? We have 20 megs per kig once a day.
So as well as given, these, drugs, we may need to think about supportive, treatment. If we've already started steroids, then usually we try and taper and stop these, unless it's required for short term management of specific diseases. So things like I MH a where we use much shorter, courses than normal.
We may also need to give these patients antiemetics and appetite stimulants and fluid therapy. So they may be, dehydrated or not eaten. And we may also need to give analgesic, so, you know, if they've got, kind of neurological, granulomas or anything.
Then that can be, painful. So, we may need to think about analgesia on a case by case basis. So the duration of treatment is typically, 12 weeks.
But there are studies which are ongoing looking at much shorter courses, So ones which have been unpublished but kind of from personal communication are looking more at like six weeks duration. But at the moment we would still recommend 12 weeks, because that's what we know, has been working, and we usually try and stop at this stage if they're clinically normal. And, lab parameters have normalised.
But I will come on to a couple of lab parameters that may not completely normalise. And some of the cases may need to extend, treatment, period. So when we're looking at monitoring response, we usually see a rapid improvement.
So we usually see an improvement in the demeanour, appetite and pyrexia within the 1st 2 to 5 days. What? One thing that is important to realise is that effusions can worsen for the first couple of days.
So particularly if you have, like a pleural effusion, I would definitely want to be keeping this cat hospitalised because we may need to repeat thoracocentesis in the early days. Neuroscience can also worsen in the first few days, and they may require things like antiepileptics if seizures occur. We also note that hyperglobulinemia may worsen, and that's because, particularly, if you've got the wet form where there's a lot of, protein rich fluid as that's been reabsorbed.
Your globulins can then increase in the blood. And we also know that hyperglobulinemia may not fully normalise. So even cats are are successfully, treated.
They may have a mild hyperglobulinemia. And from our experience so far, those caps don't seem to be at increased risk of, relapse. But it's definitely something that we need more research on.
So we can also see, an increase in a LT in cats, particularly at higher doses. And that generally resolves upon, dose reduction, or when it's stopped, Lymphadenopathy, may not fully resolve. So just like with the increased globulins, if we see a mild lymphadenopathy at the end of treatment, but everything else is normal, then we may still stop.
But if we're kind of monitoring the, response and the captures aren't improving, then we may need to review our diagnosis as well. So when we're monitoring, usually we want a verbal report after about 48 hours. So these cats should be feeling better starting to eat.
And, be more, active. And we want a physical exam after two weeks, six weeks and 12 weeks. When we're checking their history.
So doing, and doing the physical exam in and the temperature, and the weight and the weight is really important because often these cats are young kittens and they should be growing anyway. And particularly once we start treating this, they can have quite a rapid weight gain. And it's important that we then ad adjust the doses of medications to account for any weight gain.
So we aren't under diagnosing them. Ideally, at the two weeks, six weeks and 12 weeks. If effusions were present, then we would want to do, like, a point of care ultrasound just to see if they're still, present and ideally, do haematology serum and serum, a GP as well.
And then four weeks after treatment, we'd want to do kind of a physical exam and ideally, an a GP, just to see whether that is normal as well. But as you can see, you know, doing all of this kind of, the Bloods and monitoring can be expensive. So where finance are more limited, we can take a more pragmatic approach.
So, you know, we might not need to do all full bloods. We might just want to check kind of a P CV total solids or globulins. And things like that as well.
So I think we do need to tailor it to the individual patient, so we definitely can see some, side effects. But most of them aren't, too severe at all. So if we were doing injections, then it can be painful.
So we usually recommend, giving, things like gabapentin or, buprenorphine to, help with this. After IV remdesivir, we can for a few hours see depression and nausea, so we may want to or have to give things like Neopet. We can see a mild increase in a LT in about 30% of cases.
And some of those will be given things like Sammy. There's no evidence that that necessarily, helps, but it shouldn't harm. So if the cats are amenable to medication, then it's something that I would usually start.
We can also see a mild sin ofilia and lymphocytosis. And this was a study that I was talking about earlier with these unlicensed products that there have been, it has been a case report of two cats which had, unlicensed GS 441524. Who developed?
Sis. So the other thing that we can do when we're, treating with GS 441524 is to think about doing therapeutic drug monitoring. So particularly if we have got a, cat, which is not responding as expected.
And, with this it is available through the University of Edinburgh, and we know that some cats will need higher doses and will need kind of twice daily dosing. So with this, what we recommend is doing a peak sample. So, we first of all, give them kind of 3 to 5 doses of the oral GS.
And after that, we will do a peak sample 2 to 3 hours after the dose, and then do a trough sample as well. And the results can really aid to see whether we need to adjust the dose, or the frequency of administration. If we get a relapse in this case, and we want to review the diagnosis and see whether it was as robust as it can be if they relapse during treatment.
Then we increase, by 5 to 10, megs per kig per day of the GS and, split into B ID dosing if the relapse occurs, so there should be after treatment. Then we restart the dose and increase by 5 to 10 megs per kig per day and split into B ID dosing and also consider, therapeutic drug monitoring. And if we've got these really high doses and therapeutic drug monitoring is normal, we can consider E one DD 1931.
But I'd also advise speaking to a specialist because things like, propylene, immuno, timol and feline interferon or mefloquine may also, be options. So E ID D 1931. Is being now legally available in the UK for a special manufacturer.
But there's less knowledge and experience of this drug, so it's an antiviral drug. And it's a, pro drug of the mono pyro VR. And it's dosed, generally at 15 megs per kig.
Twice a day, we can see side effects, including cytopenias, which can be pan cytopenia reduced appetite, nausea, increased a LT and renal compromise. So we'd only really consider if there was a true failure or relapse with the GS 441524 or REM Devere. So I just wanted just to briefly touch on, this paper, so this was, a paper which was looking at, using unlicensed products to reduce faecal shedding in naturally infected, cats.
And what they found is that, you know, given this, medication, for, four days did find that they, were able to, clear the virus. So a lot of breeders are now kind of jumping on this study and wanting to give their healthy, animals, GS, products. And we would strongly advise against this and also the advisory board of cat diseases are strongly advising against this as well.
Because this disease is ubiquitous, these animals are probably going to be exposed again. And the problem with giving antivirals is we're probably then more likely lead to mutations. And then, if the cat does develop F IP, we may not be able to appropriately treat it with the products that we have.
So, when we're looking at, routine treatments, you know, often these animals are kittens. And, you know, we may need to be thinking about Neutering. So ideally, we perform this a month after treatment is, completed if the cats responded.
Well, unless the UN neutered state, is resulting in stress. So, you know, if you've got, like, a female cat that's constantly crying and getting very distressed, we may need to think about having, Neutering during the treatment. And if that's the case, we would want the cat to be kind of stable for at least, a couple of weeks.
Make sure that we are, using the eye a care cat friendly, clinic, protocols and try and reduce stress as possible. We don't have any evidence, against using worm and flea treatment. So we would recommend, you know, still giving that as well.
And also give vaccines as needed according to kind of WS a VA and ABC D, guidelines. So ideally, you know, waiting. Until the cat is is, finished, treatment.
But if they absolutely need it, then that seems OK as well. If the animal is hospitalised for any reason, then we definitely want to minimise, stress and look at cat friendly clinic protocols, so the prognosis can be excellent. So, you know, case, success rates, in our study was almost 85%.
And in, some anecdotally have been kind of up to 95%. And with this, you know, we are seeing cure, which is just absolutely amazing compared to that median survival time of eight days. There's several ongoing research projects.
And I said there will be one published, hopefully short, shortly looking at shorter duration of treatment. So it's likely that, kind of both the dose and potential duration of treatment will, change. And in the future, we may have even other options with protease inhibitors and other nucleic side, analogues as well.
So, hopefully you can, see with this, You know, we have this really highly, effective and, treatment, which is now available. A definitive diagnosis can still be, problematic. So sometimes we do need to consider even a trial, treatment with these drugs with the owners.
On board. The owners do need to be, committed because, prolonged. Treatment is, needed.
And it is expensive. And we do need to think about having regular monitoring during and post treatment as well. So I'm part of the F IP advice team.
Which is, composed of five, feline, specialists. So if you've got if you need any help with clinical cases, then please feel free to contact us. And the email is F IP advice at gmail.com.
Thank you very much.