Hello. Thank you so much for choosing to watch this Webinar. My name's Sarah Cay.
I'm a UK based specialist in feline medicine. And the topic for discussion in this webinar is diagnosis of weight loss. But before we talk specifically about diagnosis, I just wanted to spend a few minutes talking about weight loss in general.
And what we mean by this, it might sound obvious, but what are the criteria for concern? I guess, and how do we assess patients before focusing on, the approach to diagnosis of of causes of weight loss in cats. So weight loss, of course, is a significant abnormality in our patients.
It's non-specific. It's not a diagnosis in itself, but it definitely tells us that something significant is going on. And in cats, often they're very good at hiding illness.
But chronic illnesses and slow, insidious weight loss, often go hand in hand. And so any unintended weight loss should, in my opinion, always be a flag for concern in any feline patients that you're seeing. There are a huge number of differential diagnoses, some of which will be obvious on clinical examination or may appear obvious on clinical examination, some of which may not be.
We may need to do further diagnostics. Some of these, of course, might be more straightforward than others to make a diagnosis. And so this webinar we're going to really focus on what to do when our clinical examination doesn't give us clues what to do.
Perhaps when our laboratory examination doesn't give us many clues. But before we go into that anymore, just wanted to spend a moment talking about the significance of weight loss as in When do we When should we be concerned about this? My advice to you in terms of when to worry about weight loss, is whenever you can see that there is a downward trend in weight.
So even if that downward trend appears very, very gentle, if each reading you take is lower than the last one that was taken for that patient and weight loss has not been actively sought as in. This is not an overweight catch that you're trying to gently reduce its weight over a period of time. If that's not the case, then really, it should be cause for concern, even if it appears quite gentle and gradual in nature.
Of course, if it is more severe, and certainly if there's any loss of muscle mass, then that also should be a big red flag of concern. And I'm going to talk in a few moments about, percentage weight changes because I find that helpful when assessing patients that come into the clinic. So I'll explain more about what I mean by that in just a moment we are nowadays, I think, much better at having cat friendly scales in our consulting rooms.
And therefore we're much more familiar with getting a weight record every time the patient comes in, whether it's for a routine elective, booster vaccination or nail trim, or whether the cat is unwell. But we should certainly always, have that very much in our mind as as important on our to do list of any patient coming into the clinic. Whatever the reason, and ideally alongside the body weight assessment, if we can do a body condition, score, muscle condition, score that's helpful corroboration of the the healthy nature of that patient's weight.
Of course, a healthy Maine coon, should weigh an awful lot more than a healthy singapura cat, for example. And as I mentioned, we'll talk more about percentage weight changes in just a couple of moments. So ideally, any patient then when it comes in unwell.
We have something to compare to, and not either an empty file, which occasionally not very often but occasionally happens. Still, I find, or a file that maybe has only one or two previous weight records at all. That makes it harder for us to understand, particularly if those readings for a long time ago, whether any changes today have been recent or perhaps more long standing.
And it's much easier if we have this sort of depth and breadth of data. So this is a patient from years ago of mine called cherub, and the owner was very devoted. She came in quite regularly, So we've got a tonne of weight records, which is absolutely brilliant, and this is the sort of example of of how our practise management system also can help to to graphically illustrate weight loss.
So in this older cat, you can see that just over a period of time again, this is actually a few years that are represented in this chart, but the weight has been notching down each time. And a common cause of weight loss, certainly in older cats is often chronic kidney disease. And that can cause quite a sort of gradual, insidious weight loss which may not be noticed by owners.
This is, a screenshot of a paper, which I'm I think is just a really superb illustration of the diagnostic utility of just a simple weight check. So in this paper, which is a 2016 paper, the authors reported data from over 500 cats diagnosed with chronic kidney disease from six American vet practises. And they found that in the year preceding the diagnosis of chronic kidney disease, the cats in this study had lost a median of 8.9% of their body weight, which, as you'll come on to see in the next slide is is a lot of weight.
But in fact, weight loss in these cats was already present three years before diagnosis. So those sort of gentle weight loss that's sort of just drifting down over that period of time. Don't ignore it.
And also what came out of this study was that the cats with a lower body weight at the time of diagnosis, had a shorter survival time compared to those cats with a a sort of healthier body weight. Now, of course, this is, you know, all cats included some cats. Their healthy body weight is less than 4.2 kg.
So perhaps take that actual number with a little bit of a pinch of salt. But it's a hint here. I think that the earlier we can make the diagnosis of chronic kidney disease that the likelihood is that we're going to have a better outcome.
So we want to recognise, weight loss at the earliest possible opportunity so that we can be proactive, do the diagnostics and provide the appropriate interventions. So that paper mentions, percentage weight changes, and I've already mentioned percentage weight changes. So, firstly, how do we calculate a percentage weight change?
Well, that's shown at the bottom of this slide. It's the difference in weight. So today's compared to last time weight divided by the original weight, last time's weight and then multiplied by 100%.
And I think if you are, for example, seeing a cat, and it's It's perhaps not been in for six months, perhaps 12 months. It's just coming in for its its routine booster vaccination that if it's lost more than 5% body weight, that is a significant amount of weight. So for 4 kg Cat, if it's lost 200 grammes or more, I would definitely be concerned about that.
And it's not, unfortunately, that unusual to have cats coming in where perhaps they've not been seen for a year. They're just coming in for their annual vaccinations, and they've lost more than 10% of their body weight. And yet their owner may not have even appreciated that the cat has lost weight.
Cats are very, very good at hiding weight loss. If you're looking at these numbers and thinking, well, you know, what is the impact of, you know, full stomach, empty stomach, full bladder, empty bladder, day to day variation 200 grammes doesn't sound very much. All those sorts of questions perhaps buzzing in your mind.
I would say, firstly, that I find it helpful to compare to to a person in this situation just looking at percentage changes so an approximately 10 stone person, which is approximately 65 kg. That same 5% is half a stone over 3 kg. It's the sort of weight change which we don't have day to day.
And generally, if we've lost half a stone, it's either because we've been trying very hard to lose weight, or because we're unwell. And over the years that I've worked as a free clinician, I feel that, these figures very much make sense as well. So that 5% cut off is generally what I would use, for those cats that haven't been weighed recently.
And you're wondering if that weight change is is significant. If they have lost a little bit of weight under 5% and there are any concerns, then obviously that's a cat that should have more frequent monitoring. Don't leave it another 612 months before it has another weight check if there are any concerns.
And weight loss is especially common in older cats. Of course, there are a number of common old cat illnesses which can cause weight loss. But there are also some physiological contributing factors, so older cats tend to not have as good a sense of and taste so they can become a bit fussier.
Also, their digestive, function tends to not be as good, so their their caloric needs actually do go up. And most cats will compensate by by eating more. They may also compensate by training their owners to select more premium cat foods as they get older, getting a little bit finicky and and the owner sort of responding by going off to get the more gourmet cat foods.
But if that older cat is in a busy multi Catt household, and perhaps there are other cats that you are going to eat up all the food, they can be a bit vulnerable to weight loss. So look at the household setup as well, when considering that older cat and perhaps that older cat needs a little bit more support around mealtime. So let's move on to talk about diagnosis of weight loss.
So, of course, with anything medical, the history of the physical exam absolutely crucial. So we'll talk a bit about that. We also need to consider Well, what is the cat eating?
Has it got a normal appetite or has appetite changed. How much is it eating? What food is it eating?
Do we think that the amount that's being consumed is appropriate or is it just not eating enough? And that's why it's losing weight. So a starting point certainly is to look at that cat's nutritional status and from a a caloric needs perspective.
Resting energy requirements. R ER are a starting point for, how many calories that cat needs to consume in a day. The R ER is the energy requirements of a cat at rest in a therone neutral environment, so it very much is a starting point.
If you've got a very active cat, it's going to need more than the R ER. But if you are thinking again of a relatively inactive older cat, it's a good starting point. And as you can see on this slide, there are a few different equations for calculating R ER.
The one that's thought to be most accurate is the one in the middle. The body weight to the power 0.75 times 70.
But a really handy one. Just to remember in the clinic I find is this bottom one R ER approximately 50 calories per kilo per day. So that's just a handy one to remember when you're thinking of, calculating tube feeding needs for a patient or working out whether, a patient's, food consumption is likely to be adequate.
And it's not too far off, actually. So the the estimate R ER shown in the right hand column here, the accurate one in the middle, you can see the numbers are fairly similar. A bit of divergence as the cats, get bigger.
But, you know, for the 4 kg cat, it's pretty much identical. So that can be a useful starting point. And many, brands of cat food.
It is actually quite easy to work out the calorie content now, so you can just, you know, Google. Whatever food the cat is receiving, some brands make it very easy. I think Purina, their data, you know, often very clear so you can literally work out well, if it's having two sachets of this, you know, that means it's it's getting about 100 and 50 calories, for example, and and then work out whether that is appropriate for that particular individual cat I mentioned appetite and and the importance of looking at appetite so broadly the appetite can stay the same.
Or it may be increased or decreased in any of our patients. It's almost a a little internal, sort of gleeful moment, if you like. If an owner says, Oh, my cat is eating so much, the appetite is increased.
And the reason for that little sort of, leap of excitement, I guess, is because the differential list for increased appetite and weight loss is much more concise than the decreased appetite and weight loss, which is almost every illness that you can imagine. So common examples of polyphagia and weight loss would include things like hyperthyroidism, diabetes, malaise and enteropathy, particularly enteropathy that involve sort of large portions of the small intestine. Some less common.
Some liver diseases. Some lymphocytic cholangitis cases will be quite polyphagia. I haven't put genic on there, but obviously that would be important as well.
With any cats receiving glucocorticoid therapy or progestogen therapy. EP. I, is also, a worthwhile differential.
Although it's not an everyday diagnosis in cats and some neurological and behavioural causes of of appetite changes that we can occasionally see as well. If appetite is reported to be normal, I would include all of those possibilities. I'd also probably add in neoplasia, as as another possibility.
And then, as I've already mentioned, the decreased appetite is really anything and everything that can cause that. So that's the least helpful appetite change. Although it obviously does explain weight loss, it's not necessarily a diagnosis in itself.
So on to the history and physical exam, sorts of tips here. Well, as always, if if it's not obvious, what is the cause of of perhaps that reduced appetite or their reduced weight, depending on where we are in our, individual patient status, then taking a thorough history is always important. I put the little picture of the Siamese in here because there are some breed associated conditions.
One example would be, Siamese, are more predisposed to intestinal adenocarcinoma, which, tend to be quite small, annular masses. That can be quite difficult to palpate, but often cause a partial obstruction so sort of vomiting and weight loss would be sort of clinical signs. With that, and not always easy to palpate.
So not always easy to diagnose, particularly in the early stages. But we want to be thorough with our history. We want to be thorough with our physical exam.
Of course, in any cat with weight loss, we're going to be depending on its age, thinking about those common conditions that I've mentioned like hyperthyroidism. So is there a goitre? Is there a tachycardia?
Is there, from a more general perspective on any evidence of thickened bowel loops or abdominal masses, that would explain the weight loss, any other evidence of of ne plays or other concerns elsewhere? And at that point, obviously, we hope that there may be an obvious lead or two that we can pursue, to confirm the cause of that weight loss, whether it's some severe dental disease that needs addressing or or whether there is a palpable mass, for example. But if there's not an obvious clue, then my recommendation at this point is start with some some decent, broad, thorough blood tests where at all possible, so haematology biochemistry.
Total T four. Pretty much always worthwhile. Occasionally you will see hypothyroid cats that are very young it is rare.
But I think you know any cat with weight loss. There is a justification to including a T four in the profile. Of course, it is much more common in in cats over the age of 10.
Urinalysis, ideally as well, so that we can get information on, renal concentrating ability. But also presence of glucose, for example, that that diabetes, possibility, and depending on the prevalence of retroviruses in your area and that individual patient history, whether it's been an outdoor cat involved in fights, et cetera, et cetera, it might be appropriate to include retrovirus screening at this point as well. So let's sidestep into a case because it's always more interesting to think about problem solving when you've got, a case example in front of you.
This is a patient of mine called Spencer, who I first saw as a 15 year old male neutered domestic short hair, and the history was that he'd had a fairly routine, life, as in no, not many significant previous illnesses. He had had investigations for a heart murmur a couple of years previously, and the summary of the investigations on the slide here, but he did have some abnormalities evident on the scan, but didn't need any treatment. All of his blood work at that point was absolutely fine.
In terms of renal parameters. Glucose, thyroid levels. He'd also had a previous history of flea allergic dermatitis, which was well controlled with, rigorous flea control.
And today, the main reason his owners brought him was because they were concerned he'd lost weight. And in addition to that there, there was a recent history of vomiting. At the time of presentation, he was vomiting about once a day.
They said he was ravenously hungry. They were worried about weight loss. They also felt he was a bit lethargic.
No further information, really. In terms of of any other clues, they hadn't spotted any change in thirst. He was quite a difficult patient to examine, and in in fact, I couldn't assess his blood pressure, which is pretty unusual for for me.
But he was definitely a bit unhappy about being handled. Seemed a little bit uncomfortable, in his abdomen. But other than that there and the weight loss, there wasn't a lot to report on.
So in spite of his unhappiness over blood pressure, some cats just don't like a a cuff being put on them. We did manage to collect some blood. At this point, and, the the blood work was, you know, relatively normal in many respects.
So his haematology just had a mild ears in ofilia. But other than that was normal, his biochemistry was mostly fine. His, renal parameters were on the low side, so he had lost weight.
He'd lost some muscle mass as well as creatinine was 63. His SG MA was nine. His, breast of his biochemistry was largely with phosphates.
Phosphorus, you can see is just slightly below the reference range there. And his potassium, also slightly below the reference range. His total T four was 46 which is upper reference range, but well, within the reference range.
We did do an FPL snap as well. Which was abnormal. Concerned about that recent history of vomiting.
And that was as far as we got on that first day. And that was as much as we could do without sort of further sedation in Spencer. So at this point decided to actually send him home with some symptomatic treatment for the vomiting.
So some oral Neopot and made an appointment for him to come back a week later so that I could, assess his blood pressure with some gabapentin on board. Repeat his abdominal palpation, collect a urine sample and do some imaging, and wanted to have have a look at his abdomen and see if it still seemed uncomfortable and whether there was anything that we could feel or see that gave us further clues. So he came back a week later.
He didn't did very well with the MOUN, so he hadn't actually been vomiting. And they felt his his appetite perhaps been a bit less. So was he, You know, his appetite increased before because he'd been, you know, bringing up all this food, and, or was there something else going on?
A bit unclear. His blood pressure was fine. He was super chilled with his gabapentin on board.
I couldn't feel anything on palpation of the abdomen. We got a urine sample, which was a little bit less concentrated than than a a totally healthy cat, the US G. Less than that.
1035 cut off. But otherwise was normal. We did some survey radiographs of his chest and abdomen and being an older cat.
Really? The reason for doing this is is just occult neoplasia or occult other, you know, inflammatory granulomatous disease or bony disease. That might explain, his weight loss and as well as doing an abdominal ultrasound, which I'll tell you about in just a moment.
We got some more blood for some sort of G I profiles the verdict on his ultrasound. Was that, relatively unexciting? Overall, the bowel wall thickness was was normal.
There was no loss of layering. Pancreas did look a little bit wound up. And indeed, the the FPL level was a little bit high, So consistent with some perhaps grumbling pancreatitis.
His B 12 and folate were OK. So does this explain everything in Spence Or I guess, the next thought, you know, is he just, you know, had a little bit of pancreatitis, a bit of, you know, grumbling discomfort. Does that explain this vomiting.
And this this weight loss, is it linked to an enteropathy as well? Obviously we've not done endoscopy or biopsies at this point. We've just done the ultrasound.
So, that was I guess the initial assessment and the the questions really were based on this data, whether we should look at anything else. So this is just a reminder of the clinical history and the sort of summary findings at this point. And I guess from my perspective, some of the unanswered questions or or possibilities that remained on the table were was he hyperthyroid was, that T fours upper reference range.
Obviously, he's an older cat. Is that T four Has that was that T four suppressed by presence of the pancreatitis, but he's actually got hypothyroidism. You know, should that be something that we look into in a bit more detail?
Should we look a bit more detail at his, gastrointestinal function? Although the the vomiting seemed to settle down even off the meal, were there other things we should do there? We didn't know what sort of faeces he was passing as well.
So no clues of of API. Although having said that, the the radiograph, you may remember showed, formed faeces within the colon so it didn't look like it obviously had diarrhoea. So I I decided, really, that it was worth looking at his thyroid in a bit more detail.
Certainly, this is a common diagnosis. As you'll know, hyperthyroidism, affects about 10% of of cats aged, 10% and over. And often, clinical signs make it an easy, diagnosis and and the lab testing as well.
But there are always cases that are perhaps a little bit different in their presentation. Some, some, pic pictures of examples on this slide. So myasthenia muscle weakness that vent flexion and severe tachy can be, you know, less common manifestations of hyperthyroidism that we see from time to time.
Was Spencer in that category, or perhaps that sick ey category I referred to as well, he didn't have a an obvious goitre, but it's not always easy to to feel for a goitre. It's definitely worth feeling for a goitre because if you do feel one and you have compatible clinical signs, it raises the possibility of of, that diagnosis, being more likely. Of course, we still need to confirm it with our laboratory tests.
Some cats do have quite small goitres, or they're just difficult to examine which sense it could be. Sometimes the thy tissue is just not palpable because it's ectopic. It's within the chest, or it has arisen in the neck but just slid down with gravity.
As shown in the video. Sometimes it can be helpful to alter the the head position, turn the head to one side. It then makes it easier to feel small goitres on the other side.
So if the cat's head is turning, in this example, the cat's turning to their left, then small nodules on the right hand side can be a little bit easier to feel. But irrespective of whether or not we feel a goer, we do need some lab tests to confirm hypothyroidism, and the screening test that we typically use is our total T four test. And we use this because it does in general have a high sensitivity and specificity for diagnosis of hypothyroidism.
So very often it's all we need to do to confirm our diagnosis. Always worth mentioning that test are not always perfect. Just just because it comes with a print out doesn't mean that necessarily.
It's always correct. So if in doubt, if we get discordant results, I would always question the results rather than our clinical hunch. So certainly if you do feel that you know, your gut feeling is you're dealing with a hypothyroid cap, but you get a normal result then then one of the things to do is question the methodology.
And if you've perhaps done that test in house, which many of us do, then perhaps consider sending a sample to an external diagnostic lab and the lab that, I would often consider to be the best for hormone assays is nationwide specialist labs, the one that that changes its name every 5 to 10 years. So the hormone lab and, Cambridge Specialist Labs, is also the same place. So why might we see a normal, totally foreign a cat that has got hyperthyroidism and obviously thinking of Spence?
So this was one possibility going through our mind. Well, is it because of the pancreatitis suppressing his total T four. What we call the sick E thyroid phenomenon.
Or could it be because he has early, thyroid disease? And it's just that the levels are fluctuating in and out of the the reference range, and they're just not dramatic to identify. Could it be a bad lab result?
So those are the sorts of possibilities. Generally, if the total T four is in the lower half of the reference range, then hypothyroidism is unlikely, but not impossible. But it probably the main times I've seen that have been caps with very significant concurrent disease.
And really, that's the thing that needs the management rather than the hypothyroidism in some situations. Particularly the cats that are, you know, relatively well, then one option if we've had that normal result and we're just not quite sure whether or not to completely believe it, I guess, would be to just monitor the cat, monitor its weight watch and wait for other signs of hypothyroidism, and potentially repeat that T four at a later date. But obviously, if there is more of a pressing concern over weight loss, then probably we're going to want to do things a little bit sooner, and that's where reference laboratory and other tests might come in.
And I just wanted to very briefly divert into, some of the published data. Looking at some thyroid tests in Cats and Mark Peterson is someone who's done a huge amount to advance our knowledge of hypothyroidism. He was, in fact, the person who discovered hypothyroidism in Cats in the late 19 seventies and continues to publish many studies looking at, many aspects of hypothyroidism, including diagnostic utility of different tests.
And this is one study where he had, a A population of cats in total, over 1000 cats that were presented to his clinic, where hypothyroidism was suspected because of compatible clinical signs. But ultimately, hypothyroidism was confirmed in only 917 of those cats the the rest of the cats, 221 cats actually had other causes of their weight loss. And so he then, showed in a table, which I've, put on this slide.
The different lab results for these two, groups of cats. So the hyperthyroid cats confirmed cases in the left hand column. The cats that had signs consistent with hypothyroidism but were diagnosed with other non thyroidal disease in the right hand column.
And then you can see the free T four Total T four and total T three lab results shown, and subdivided according to whether they were high, normal or low. So there's a lot of numbers, a lot of mess on the slide. But essentially, if we look at the total T four results, you'll see that the hyperthyroid cats well, 91% of them had a high total T four in 9% it was normal.
So the sensitivity of this test was 91%. The specificity of the total T four in this study was 100%. There were no false positives.
So that's why it's a good screening test. You can see the total T three in the the rows below is not a good screening test just because, the sensitivity is so poor. Only two thirds of cats in this study had a high total T three.
So total T four good screening test For those reasons, Why not the free T four? Well, it is very sensitive 98.5% of the hypothyroid cats had a high free T four.
But there were some false positives in this study. 6% of cats with non thyroidal disease had an increased free T four. So this is why the total T four is still suggested as a good screening test.
Because whilst the free T four is more sensitive, there is a risk of false positives in cats with non thyroidal illness. More recently, Mark Peterson has also looked at TSH utility in the same situation. And in this study, he, reported TSH values as either measurable or low, low being less than 0.03 nanograms per mile.
He had the same sort of group of hypothyroid cats. But he also had, some healthy age match cats, in the right hand column. And then the middle ones are, the cats that he called in this study suspect.
But it was again these non thyroidal disease cats, cats that had clinical science compatible with hypothyroidism but ultimately were confirmed to have another illness. And what you can see is that 98% of cats with hyperthyroidism have a low TSH value. So, a low TSH is very sensitive for the diagnosis of hypothyroidism, but unfortunately, it's not a good screening test, because you can see that actually, 15% of the suspect cats and a third of the healthy cats also had a low TSH.
So it's not a good screening test on its own. It's much better if you add it to another parameter. So in, if you add it to the free T four in the suspect cats that had a high free T four, all of them had measurable TSH.
So that was, one way that hypothyroidism could be excluded. Whereas the hypothyroid cats with a high free T four none of those had, measurable TSH. So TS HR C is sensitive.
A low TSH is sensitive for the diagnosis of hypothyroidism, but but not specific because there are 30% or so false positive results. Combining it with a total or three T four gets you much better sensitivity and specificity. And if you have a high normal, total T four, or a high free T four and measurable TSH, you may be better just watching and monitoring that patient rather than leaping into treatment.
So being one of the most common diagnoses that we make in practise, I hope it's been useful just to have a bit of a refresher on those difficult hyperthyroid diagnoses. So the total T four generally is accurate, reliable. But if you get a result that doesn't agree with your patient assessment, consider repeating it.
Consider sending that sample to, a reference laboratory. The free T four, preferably equilibrium dialysis methodology, which nationwide specialist labs use is also helpful. And if you have a high free T four and upper half of reference range, total T four and compatible clinical signs, it's likely that cat has hyperthyroidism TSH, low or undetectable in cats with hyperthyroidism.
So it also can be useful in combination with the total and or free T four. And if you do all that and the results are still not really helpful a bit on the fence or equivocal type results, there are other thorough tests you can do. I very, very rarely do these anymore.
But T three suppression TRH stem tests TSH stem tests are all examples. If you have access to synth grey. That's actually a lovely way to, not only diagnose hypothyroidism, but also show you where that hyperthyroid tissue is.
So this is a a synth gra image cat on a gamma camera, having had some radioactive technetium and the head at the top there, the salivary tissue actually takes up technetium in the same way that the thyroid so you can see salivary glands within the cat's head. This is sort of like a Dorsa ventral cat, on the gamma camera, and then within the neck, you can see, a very hot thyroid on one side. So it's It's much more intense than the saliva tissue because it is hyper functional and therefore visible so it can be useful not only to diagnose the hyperthyroidism, but also in this situation to tell you whether or not you could operate on that cat.
And remove that, thyroid. So back to Spencer. What did we find?
Well, his, in-house Total T four was 46. You might remember. So I did send some blood off to nationwide specialist labs.
Their total T four was similarly within their reference range, upper reference range. The free T four, however, was elevated, and the TSH was low, so consistent with hyperthyroidism. So we did start Spencer with treatment.
This is actually now, 18 months ago, I guess. And, he's done very, very well, actually. Saw him, just a week or two ago, recording this end of April 2024.
And he's still doing extremely well. He has had occasional flare ups of his pancreatitis, which respond typically just to a few days of me. But generally is is doing very, very well.
So what about other situations where, you know, we've done perhaps the the Spencer approach? We're still struggling to make a diagnosis. Well, often, the gastrointestinal tract is the next place to really focus on.
Sometimes owners don't know what faeces the cat is passing whether or not they're normal or the cat has diarrhoea. But certainly any insight on that can be helpful. Potentially looking at bile acids might be helpful as well.
The more G I, blood profiles as well. So B, 12 folate, for example, FPL for pancreatitis or PL. I, or and the TL I trips in, like, immuno activity, useful for a diagnosis of exo pancreatic insufficiency.
And I've already mentioned retrovirus testing, but that again would be the sort of thing. If we're not already done at this point, I would I would include it. So another little case vignette just to, introduce, some of those, possibilities here.
This is, zisa, a five year old female, neutered British short hair. And her presenting problem was weight loss in spite of a normal appetite. Ona definitely was aware of diarrhoea in her as well.
Soft to liquid stools and borba me very gurgly guts. And also, quite voluminous faeces. So they typically, were were soft.
Sometimes formed, sometimes more liquid, but quite often pale and very long. So passing 15 centimetre long faeces twice a day. Often, she had poor coat condition.
An inflammatory enteropathy had been suspected. But she'd not responded to any dietary trials. She'd not responded to antibiotics.
I have a feeling also that they had used some, glucocorticoids in her and she'd not responded to that either. So certainly my thoughts at this point were, well, the pale and voluminous stool definitely raised my concerns over EP I as a possibility. And so that was something that hadn't been looked at so far.
And indeed, she hadn't had, B. 12 folate tests done either. So, I made that recommendation.
And this was her results. We also did a PL I in her, and you can see that her TL i levels were low. Consistent with ex pancreatic insufficiency.
B 12. Also very low. Which is quite common in cats with this condition.
But this is a condition that whilst it can be a bit challenging, sometimes with acceptance of supplements, can often produce good results. And happy to say that for her B 12, and, pancreatic enzyme supplements, have been extremely effective. EP I is probably still under diagnosed, in practise.
It's not an everyday every week diagnosis, but it probably is relatively underdiagnosed. I think. This case series not too long ago had a large number of cases reported, so probably a useful just summary of sort of things to keep our eyes out for you'll see that a huge range of age is reported from the very young to the very old.
Lots of cats are relatively young when diagnosed with this condition. There are some breeds that are overrepresented, including the British short hair, which CSA was but also Siamese rag doll Maine coon, slightly overrepresented. Also male cats, and quite common to have concurrent disease, particularly gastrointestinal and pancreatic.
So, pancreatitis, Diabetes being very much amongst those and clinical signs typically do include weight loss. 91 per cent of patients, often in combination with unformed faeces, and then a range of other abnormalities, including the the coat changes that were present in ziza and sometimes appetite changes, sometimes reduced, sometimes increased from this study again. It's a large number of cases.
About a third of the cats had weight loss, unformed faeces and an increased appetite. Just over half the cats had weight loss and unformed faeces, so weight loss and unformed faeces should certainly raise your awareness. If there's an increased appetite there as well.
Then that that helps add to, the limit. And typically the faeces are voluminous and pale. That, that is, is relatively common, sometimes greasy as well.
And sometimes the coat can be quite greasy as well. Many of these cats have very low B 12 levels and often need lifelong supplementation with B 12, treatment. Not always straightforward.
In this, case series, 60% were reported to have a good response to treatment. So, what else can we do in those undiagnosed, weight loss cases? Just to to finish off the the sort of diagnostics.
Really? Well, survey radiography. I talked about a bit with spencer already, but certainly survey imaging can be helpful.
CT, if you have that available obviously is is fantastic at finding abnormalities as well. I guess the main challenge can be sometimes interpreting the significance of that. But if funds are available for that sort of fine tooth comb approach, and nothing else has has yielded in sight.
Then that would be an appropriate place to go. Older cats have already mentioned I think pulmonary neoplasia being a consideration. That's a reason for including the chest X rays and a weight loss case.
Abdominal ultrasound. Of course, we've already touched on a bit there, symptomatic or trial treatments where we could for those less urgent cases, consider po potential diet trials. If perhaps there's not funds to go for the sort of investigations we might want to do.
Endoscopy and biopsy if there are more funds, laparotomy and biopsy. also, of course, on the list, because G I disease is is a common but can be quite hard to, confirm the diagnosis as a cause of weight loss and just a graphic illustration of of, how good cats are at hiding. Illness.
This this elderly cat came in with really primarily a sore toe. No. Other, clinical signs of concern were reported by the owner, although the cat had obviously lost weight according to the practise management system.
But having radiograph at the toe, one of my colleagues, wanted to do further survey radiographs, and you can just see there's a huge amount of pathology, within the chest. No respiratory signs at all, high index of suspicion of of neoplasia, with this cat. And, and yet, not making it very easy for us to make that diagnosis.
So finally, what about managing? Undiagnosed weight loss. What can we do to, support these patients, that have weight loss.
And, perhaps even if we haven't got to the bottom of the the cause of that weight loss. Or perhaps if we have but just are needing, you know, as much support as we can lay our hands on. Well, from a diagnosis perspective, often it is that repeat monitoring, repeat assessment, which ultimately gives us the answer.
So if we if you're struggling, know that you you know, you're not alone. Some of these cases are really difficult cases to diagnose, But as time goes by, they tend to make, the the pathology tends to make itself more evident. And all you can do in that period in terms of diagnosis is just repeat your history.
Repeat your physical exam. Repeat some of your, tests as well. Your diagnostic tests non-specific support that you might want to would include support for appetite where appropriate, high calorie recovery, convalescent type diets, potentially B 12 supplementation.
For if you are concerned about G, I disease and maybe funds don't exist to to, pursue that a little bit further. Anti-nausea, treatment trials, analgesic treatment trials can all be considered. And we'll just finish off with one last sort of case Where really support is the emphasis.
But this is, Leo, a 13 year old male, neutered domestic short hair. So has a diagnosis of chronic kidney disease. Prior to when I first met him.
He'd, had that diagnosis for some time, I think about 18 months or so. His most recent check was four months before I met him. And at that point, his own told me.
Well, his appetite seemed Seemed fine, she said, but he just isn't really keen on the renal foods. He's eating other foods. Absolutely fine, but I think he has lost some weight.
And indeed, on assessment, he'd lost a huge amount of weight. He previously weighed 3.5 kg and now is 2.7 kg.
So he'd lost 0.85 kg, which equate equated to 24% of his body weight. An absolutely massive amount of weight.
He was a little bit dehydrated, so some of that that weight loss. Potentially a little bit of it was fluids, but, you know, largely I think he he'd lost a lot of condition. Him just a silent video for you, but just showing him sitting very, very meekly in his carrier.
We collected some blood and urine from him so we could assess his renal status and work out where we could support him best. And his azotemia was very much worse. Some of this most definitely an acute on chronic.
So some dehydration on top of the CKD, which needed correcting. But beyond that wanted to look at how best we could support him. I was suspicious.
His appetite wasn't as good as his owner felt. Because whilst she said he was eating these other foods, fine, I Yeah, I was. I was a little bit more sceptical.
We'll come on to some of the data collecting in just a moment from that perspective. But general tips for CKD and appetite and weight support on this slide Really? It's all about, in my view, finding fixable issues which undoubtedly will help things like dehydration, electrolyte imbalances.
If we diagnose those and can treat those that undoubtedly is going to help support appetite. But beyond that, we might also need to consider appetite, stimulants and other medications as appropriate for that individual. In Leo's case, we did correct a dehydration.
I actually recommended that he, in view of the severity of his renal disease, had some sub cutt fluid. Support continued at home, which his owner was happy to do. And I asked her to keep a food diary of what Leo was eating and let him eat whatever wanted initially.
And so she did keep a very good diary. He was eating 200 to 280 grammes of wet food a day at home, and she told me the foods he was eating, I was able to look up the calorie content. It was mainly eating gourmet pearl and Felix soup and calculated, his daily calorie intake was between 100 and 30 100 and 80 calories.
So, is he eating? Enough is I, I guess. The the next question.
And, I'll remind you as well that he had weighed 3.5 kg. He now weighed 2.7 kg, so eating 100 and 30 to 100 and 80 kg calories.
Is that enough? Well, 100 and 30 calories is is not enough. It's 100 and 80 calories.
Well, it's, you know, putting them in this sort of range of of calorie consumption, which is perhaps OK for a cat with a body weight of 3.5 kg on those good days. But, thinking of of his, perhaps healthy, ideal body weight I, I felt that was that was not enough calories.
So and particularly on the bad days when only consuming 130 kg calories. So, and just for comparison, some calorie dense renal diets, shown here the number of calories per 100 grammes is very much higher than many of these delicious gourmet foods, that are available in the supermarket. So we we spent some time working on Leo's appetite and added, some meta to support that which which definitely, helped to improve his body weight significantly.
So I hope that's been, a useful session to discuss weight loss in cats in general. When to view it as significant, what sort of approach I find helpful for problem solving these cases and also some of the tips for supporting cats with weight loss. Particularly if appetite is poor.
Please do also feel free to visit my website vet Professionals.com, where you'll find, under the helpful info section. There's a lot of free to access resources.
The video tutorials include some webinars, some for vets, some for owners. And, I hope that overall, this has been a worthwhile use of your time so that the next cat or cats you see with weight loss, you feel perhaps more, confident or inspired in in terms of how to assess and how to manage them. Thank you very, very much again for choosing to watch this webinar.