[00:00:02] Introduction: Welcome to All Cats Considered, a podcast from the Feline Veterinary Medical Association.
Here we interview professionals from across the veterinary world and take deep dives into the latest evidence-based research, developments, studies and guidelines that improve feline health and well-being.
We are the home for veterinary professionals seeking to enhance the care of cats through high standards of practice, continuing education and evidence-based medicine. In each episode you'll hear interviews with a variety of experts in our field covering a wide range of topics and the latest developments in feline health. We'll share the key points you need to know to improve your patients care.
Let's dive in and listen to this week's experts.
[00:00:44] Gómez‑Mejías: So welcome to another episode of chattering with iCare. I'm Yaiza Gómez‑Mejías, iCare Veterinary Community Coordinator and today we are diving into epileptic seizures in cats. Identifying the underlying cause of feline seizures is often a challenge. The range of differential diagnosis is incredibly broad and it can be very difficult to identify.
Joining us today is Dr. Mark Lowrie, co-author of the recent Clinical Spotlight review in the Journal of Feline Medicine and Surgery. He will help us navigate the diagnostic approach to ensure that we don't miss anything important.
So hi Mark, and thanks for joining us today.
[00:01:23] Lowrie: Yeah, hi guys. So nice to have me. Thank you. And thank you for your time and everything today. I look forward to the podcast ahead.
[00:01:30] Gómez‑Mejías: I really look forward to this conversation as well. Seizures are such a fascinating thing to talk about. So in the review, you highlight that the cat signalment is a major diagnostic clue. How should the patient's age or breed influence our list of differentials?
[00:01:50] Lowrie: Yeah, well, I suppose I'd start by saying signalment is really important in cats with seizures and age is probably the biggest part of that. So if I'm seeing a young cat, maybe sort of let's say under five years old, with a normal interictal neurological exam and normal screening blood work, then I would say idiopathic epilepsy becomes just that bit more plausible.
I'm still careful in cats because idiopathic epilepsy is definitely less common than it is in dogs. But that age group does make it a lot more realistic.
As you move through to cats into middle age, that balance shifts quite quickly. So older cats are much more likely to have structural epilepsy or reactive seizures.
So my list of differential diagnoses leans heavily towards things like neoplasia, vascular disease, inflammatory or infectious encephalitis, and maybe some metabolic causes.
And then the other side of signalment, of course is with breed. I mean, breed does matter as well, particularly in pedigrees because there are some syndromes where the signalment is almost part of the diagnosis.
A classic example is feline audiogenic reflex seizures and in that scenario it's often an older cat. And among pedigrees I suppose the Burman is overrepresented. So an older Burman with sound triggered shock-like jerks, sort of a myoclonus immediately moves that syndrome right up the differential diagnosis list to the top.
So signalment doesn't give you the answer, but it absolutely changes the weighting of your differential diagnoses before you've even started the workup.
[00:03:32] Gómez‑Mejías: Is there any known cause for this increased predisposition in Birman cats to audiogenic seizures?
[00:03:39] Lowrie: That's a really great question. And you know what, the Birman cat is so overrepresented it really makes you think there has to be some clear genetic cause there. Now we've, we've looked into it, we've had a little bit of look to see whether there could be an underlying genetic mutation or some kind of tendency towards it and we haven't found this. And I think it's more important to say that what we haven't yet been able to do is find what the pathology is of these cats because they are older cats, they, they're aging, they've got cognitive decline as well as the myoclonic seizures.
We haven't been able to find pathology associated with that, which suggests it's kind of much more at the cellular level I suppose is what I'd say.
So a very. My quick answer is no. But the longer answer would be there is bound to be something there. I mean any cat can be affected with feline audiogenic reflex seizures, but the fact Birmans jump out, it's obviously a slightly more unusual breed.
And the fact they were overrepresented in this sample is really quite significant.
[00:04:42] Gómez‑Mejías: Getting back to the neurological examination, you emphasized the need to repeat it once the postictal phase has resolved. Why is that? Are there any transient changes likely to mislead us when we examine the cat just after having a seizure?
[00:04:57] Lowrie: Yeah, I mean that's a really practical pitfall. The postictal period can produce these transient neurological abnormalities that look exactly like structural forebrain disease. Cats can be disorientated, they pace, appear centrally blind, they seem behavioral abnormal and they can even look a little bit weak and ataxic. So if you examine them right then it's very easy to over interpret that and conclude there must be a structural lesion.
So we always recommend repeating the neuro exam once the cat is clearly back to normal.
The other reason is that owners may describe odd behavior between seizures, but sometimes what they're actually describing is a prolonged postictal change rather than a true interictal abnormality. And I think it's really important to separate those two things out because it makes a big difference to your diagnostic reasoning.
And I suppose there's one really important caveat here.
Severe violent seizures can cause real injury.
And by that I mean particularly excitotoxic injury in the NMDA receptor-rich areas like the hippocampus.
In those cases, deficits may persist beyond the postictal period.
But in the average case, repeating the exam once the postictal phase is resolved prevents you being led down the wrong path. And usually I'd say a 24 to 48 hour period following the seizure is a reasonable timeframe to wait to repeat that examination.
[00:06:28] Gómez‑Mejías: I was going to ask you that. I made me giggle how you talk about the areas in the brain as you were talking about the living room in your house. It was such a.
[00:06:38] Lowrie: It's true that, you know, I like that. I like that analogy. No, that you're right.
It's the best way to think about the brain. It's so easy to think of it as a black box, but yeah, think of like, you know, there's certain parts of your house that are really important. So the kitchen, you know, is where you prepare food and things and that's where all the organization of things goes, you know, and then the corridors, if you like, or hallways where things run. So that can be the thalamus, where it's sort of allowing things to go down to things like the brainstem. The brainstem's so crucial for everything, you know. And then you can sort of think of the brainstem as being more like the places like the living room where it's just a vital place where you need to hang out and enjoy and sort of relax and does things that our mind maybe isn't completely aware of. So. Love that analogy.
[00:07:23] Gómez‑Mejías: I'm glad I came completely randomly. But yeah, I think we need that sort of thing to learn about neurology because it's. So many vets get stuck in that. I got stuck for ages, particularly while studying for, for the, for the last exam.
You and your proceedings helped me so much. You know, all the articles you've written? It's a, It's a pleasure to. And an honor to be speaking with you today. Could you clarify the fundamental differences between reactive seizure structural epilepsy and idiopathic epilepsy in cats?
[00:08:02] Lowrie: Yeah, I mean, absolutely. I think I would think of it as three different buckets or baskets. You know, each bucket has a different implication.
Reactive seizures are where the brain is structurally normal, but it's reacting to a systemic problem. That could be something like, well, metabolic disease, like hypoglycemia.
Other ones to mention, I suppose, in cats would be hepatic encephalopathy, electrolyte disturbances.
Really, key one is severe hypertension. Hypertension is so important in cats.
Uremia. Obviously we see uremia a lot and of course, always toxins. They're always on the list as causing metabolic disease. But the key idea is fix that systemic trigger and the seizures should resolve. That's reactive seizures, as I say, in one of the buckets.
Then we move to structural epilepsy. So that means there's a lesion within the brain itself that could be. Well, the one owners worry about is neoplasia. Of course, inflammation or infection, vascular disease, malformation.
And people refer to trauma. I don't like saying trauma. Trauma's not great. But, you know, when I say trauma, I mean something that's caused significant damage to the brain, whether it be a fracture, causing depression or contusion of the brain, parenchyma itself.
But these are all things that would result in structural epilepsy.
The important thing here is these cats have interictal neurological abnormalities, although not always. I mean, especially early in the disease, they might not show problems. And another time when we may not see signs in between the seizures would be if they have a lesion in a silent area of the brain.
So a common part would be the olfactory lobe. I'm already thinking back to what we said. You know, what would the olfactory lobe be in the house? I've not come up with that yet. Maybe the attic. It's a part that doesn't matter too much. It's just got some storage space there.
But I say it doesn't matter too much. It's vital for pets, you know, dogs, cats, Cats, it's so important. They've got their sense of smell. So I think in cats it's far more important than it is in ourselves.
It's a lobe in cats, it's a nerve in ourselves. The other third aspect to talk about is idiopathic epilepsy, and it's a diagnosis of exclusion. So recurrent seizures, a normal interictal period, and no evidence of toxic, metabolic, or structural intracranial disease after appropriate investigation would really lead you down the path to saying this is idiopathic epilepsy.
And in cats, I mean, it is much less common in dogs. We do tend to be slightly more cautious about playing sort of applying that label without thorough exclusion of other causes. So we definitely see it, but I think it's fair to say we don't have a strong handle on it in quite the same way we do in dogs. And we are a little bit more hesitant with how we label cats as idiopathic epileptics.
[00:11:05] Gómez‑Mejías: Oh, that's such a clarifying answers. Thank you so much. Why don't you like to use the word trauma?
[00:11:13] Lowrie: Well, simply because trauma. So trauma isn't really a disease, I suppose, is what I'm coming to. Trauma may well be the inciting reason why we've had a problem in the brain. So definitely you can have trauma to the head, you can be run over by a car, whatever it might be for cats. But I, I think the important thing is why is the cat seizuring? It won't be the trauma, it'll be the result of the trauma. So then you've got many results of the trauma causing seizures. So, you know, I could break. As I say, you can get a depressed skull fracture. So you've got compression of the brain.
You might have contusion of the brain. So actual swelling and bruising of the brain. You might have concussion. I mean, concussion's a really important one.
We see a lot of cats following trauma where they have got some kind of brain or spinal cord concussion.
And the way we know it's concussion is we do advanced imaging. So an MRI scan. If I had a cat with concussion, this cat can be showing quite obvious neurological abnormalities. I'll do an MRI scan of the cat.
I might find bruising in the.. well, you don't get much muscle in a cat, but you might find bruising or something in the soft tissues around the head. But the brain itself will look completely normal. And you've sort of. Then, I mean, I remember this caught me out years ago. I was sort of like, well, I've got this cat with very obvious signs, but everything about the brain is normal. How can it possibly be showing having four brain signs when the brain's in normal? And it's quite simply the concussion is a change very much at the cellular level. So there are definite problems within the brain. There's abnormalities, but they're not macroscopic changes, they're microscopic. And what we tend to find with concussion is it's something that improves with time. And of course we get it. You know, if we're, if we're involved in some kind of severe trauma, car accidents, things that involved head trauma, you will have people that have quite severe concussion. They're really not with it at all. But give that brain time and it will repair itself.
Rugby would be a good example. Rugby players, you know, they're playing rugby, they're having concussion all the time now. They get used to it. And these professionals are going around with concussion a lot of the time, but they manage, you know, they do okay. But over time, repeated concussion is a problem. And that's why obviously we see problems with rugby players developing brain injury years and years later.
[00:13:33] Gómez‑Mejías: I was going to say when you said they get used to it, I was wondering up to what extent they get used to something like that.
[00:13:38] Lowrie: Well, it's a short term, short term coping strategy. These young professionals, they're fine, you know, they go out every day and play their rugby, they do the practice. But you're absolutely right. The long-term problem with it is it leads to, it leads to serious issues.
[00:13:52] Gómez‑Mejías: Wow, I did that. So. Yeah. Surprising. I didn't know. I mean, I didn't know about the. Yeah, but it's. Yeah, it's interesting.
[00:14:03] Lowrie: So that's where trauma comes from. You know, that trauma can. I'm happy for trauma to be a cause, but I want, I'd like to be a lot more specific about why.
[00:14:10] Gómez‑Mejías: Specific. Yeah, we are, we shall be specific. That's, that's super, super helpful. Thanks so much. Getting back to the article again, you describe owner recorded videos as invaluable. So what specific behaviors or signs should we look for in these videos to distinguish a true seizure from other problems like syncope or Paroxysmal dyskinesia
[00:14:35] Lowrie: Oh, you've got my favorite topic now. You won't shut me up now because videos are genuinely one of the most useful tests.
I mean, honestly, every time I have any patient come in, it's really helpful to get a video of what the owners are seeing at home. And cats are the poster child, if you like, of this, where cats won't walk around, consult rooms, all this sort of thing. And if an owner can bring a video of the behavior they're seeing at home, it really helps. Clearly, for seizures it's more important again because seizures are discrete episodes.
As vets, we're fairly fortunate that it's rare we see them. It is the owners that suffer them at home. So I like them to capture a video of the seizure. And what I'm looking for, I mean, I'm looking for a paroxysmal onset and end, a kind of stereotyped pattern between the episodes.
Involuntary motor activity, that's really important. It can be hard to know if it's involuntary, but obvious paddling of the legs is clearly an involuntary reaction and ideally some evidence of altered awareness.
That can be really hard to get on a video. And so that's where I'd really be sort of pressing the owner for their view on things. Be careful because if you say, is your cat aware? They'll often say yes because the cat's eyes are open.
And we know from seizures, all seizures, cat's eyes will be open. So it's really important to say, can your cat respond to you? Is what I'd look at.
Another really important thing is autonomic signs really helpful. Hypersalivation is a big one in cats.
So frothing at the mouth we might see or just excess saliva. And I suppose urination and defecation can be supportive.
Another thing we need to differentiate from is syncope. And syncope tends to look different.
It's usually a sudden collapse with a loss of tone. So flaccid, rather than increased tone.
And recovery is often rapid. And I'd describe it as clean, really, with little or no post event confusion, cats snap right back out of it.
Also, syncope is more likely to be triggered by exertion or excitement.
Whereas many epileptic seizures occur when a cat is resting or relaxed.
You may, I suppose the one thing I'd say with syncope is syncope. Generally, you know, we're thinking cardiovascular or cardiorespiratory problems.
Syncope is something that is very much cardiovascular or cardiorespiratory.
We do get syncopal-like episodes in neurology. And the main one I'd think of would be cataplexy or narcolepsy.
Now that often comes on with excitement, exertion and feeding. Feeding is a common one. But there's, I mean, you'll often see cats can have that. Well, I say often. It's a very rare diagnosis. But I have seen videos of cats that have cataplexy where they're ready to kind of, they're kind of creeping up on their prey, maybe about to catch a mouse or a bird outside, and they're, they're ready to go. As they start running, that exertion is enough to trigger an episode and they just completely collapse.
So that's the one neurological time we will see decreased tone. If we see it at any other time. That for me is syncope. And that's why I bring that up and mention it.
Paroxysmal dyskinesia. So a sort of movement disorder. They're getting more and more common now. And we do see them in Sphynx cats. We see them in other breeds too, but the Sphynx is the one that we've kind of recognized that the first, if you like.
But they can look really dramatic. The cat's typically conscious throughout, so he's able to respond to an owner. But the episodes can last much, much longer than a seizure. And there's no real postictal period. I mean, these episodes can go on for 10, 20 minutes.
And if you have a cat suffering a generalized tonic-clonic seizure for 10 to 20 minutes, you would fully expect a long postictal phase.
But with the paroxysmal dyskinesia again, they come straight back out of it and come back to normal. But the movements in dyskinesia can be sustained, sort of twisting, flailing, almost dance, like in the legs as well, with how they're moving the legs, rather than the more classic tonic-clonic pattern where you've got quite violent paddling movements.
So the summary for me is the video lets you slow it down and ask, is this stereotyped? You know, is this the same sort of episode each time? Is there altered awareness? Are there autonomic signs? And how does the cat recover after the event?
[00:19:22] Gómez‑Mejías: Thank you. And that summary helped as well. Just one little thing about the response. How should we advise the owner to evaluate whether the cat is responsive? Because in that moment, the situation is quite stressful and is there any tip you can share?
[00:19:42] Lowrie: So first time round, forget it. I think when you see your cat have one of these episodes, whether it be a dyskinesia, a seizure, or a syncopal event, very, very stressful. So I think as time goes on, if you can offer reassurance, I mean, as cat has these episodes, usually they're a minute or two, maybe up to 10 minutes, they're going to happen. The cat hopefully will return back to normal or have a period of normality before having another event. So owners will become more familiar with them, is the word I'd use. I don't want to say they cope with them better, they're more familiar with them.
So by the sort of second, third, fourth time, they will start to see a pattern. And I think that allows us to reassure and say, well, look, you know, each time this happens, if this is a seizure event, sudden death from seizures is exceptionally unusual. I'll never say it doesn't happen, but is exceptionally unusual.
Things like dyskinesias, they're benign. Benign in terms of life is what I mean. You know, I mean, there's plenty of problems and comorbidities they might be associated with, but actually for the cat itself, it's a completely benign procedure, other than the discomfort, if you like, of the episode itself.
So when an owner's a little bit more hardened, shall we say, to these episodes, I would. I mean, simple things like name calling, getting a toy, maybe if they like playing with a toy, if it's a young cat and enjoys playing with a toy or something, maybe getting that. Just see. Is the cat able to follow it and see what's happening? Because cats are pretty tough. They like to know what's going on around them and they hide disease as best they can until the last, last moment. So these sorts of interactions, doing things, you know, your cat would normally respond to you for even stroking, you know, stroking a cat, you might find they just are trying to kind of come up and get comfort from you by knowing you're there. All these things show some form of awareness. Whereas a generalized tonic-clonic seizure with loss of awareness, I mean, in fairness, you would know because you wouldn't be able to get near the cat or dog, it would show a very different behavior. I mean, it would be. Scrabbling, potentially could hurt you, which, you know, with many cats, they would be devastated if they did that to you normally. But it shows there's an involuntary lot of awareness at doing that. So they're the sorts of things I'd be looking at. But every cat is different here and it's important for the owners to know their cat, to know what the right method is to try.
[00:22:02] Gómez‑Mejías: Thank you so much. Are there any specific clinical markers during a seizure that can point us toward either idiopathic or structural causes?
[00:22:14] Lowrie: Yeah, there are some patterns that maybe nudge you one way or the other, but nothing is absolute. For me features that increase suspicion of structural epilepsy include focal seizure types. That's always been described as something that might be more associated with structural disease.
Not always. You know, if you have a cat with partial seizures, I wouldn't be jumping and saying this must be a structural cause. Very often we can rule it out and find it is more an idiopathic event. But. But focal seizures types, behavioral or psychomotor seizures. So behavioral, I use that word because it's much easier to understand seizures that show an abnormal behavior. But psychomotor is probably a better term we use there. So tail-chasing, this kind of thing.
I mean, even intermittent, unprovoked episodic aggression. You can have a lovely, lovely cat that suddenly becomes quite aggressive and upset in an instant.
And then I suppose the other really important one that might increase structural epilepsy is seizures that change over time some way in which the character of the seizures changes.
If the episodes are becoming more complex, more frequent, or are accompanied by progressive interictal changes, those structural diseases really rise up the differential diagnoses list. And a big question I always ask my owners of cats with seizures is I kind of ask them to take a moment to forget about the seizures and tell me about their cat in between the seizures. How is their cat? Is their cat normal day to day as they've always remembered them, or has there been some change? Because actually, for me, that's far more important than the seizures themselves. It can be hard because owners obviously tunnel vision on the seizures. That's why I'm here to see you. But it's like, no, actually, the behavior around the seizures for me is far more informative than the seizures themselves.
Then I suppose, on the other hand, a cat with generalized seizures, a completely normal interictal neurological exam and behavior and no progression over time, for me, that fits really well with an idiopathic epilepsy.
But the honest answer to the question that you've asked is cats can be really deceptive. And that's why we tend to lean much more towards imaging much more readily in cats than we do in dogs. Doesn't mean to say we have to. Every cat's different. Every owner we deal with will want different outcomes. Not a different outcome, a different method of looking at what the cause is. But I do think with cats, MRI is something I'd go to much faster than I would in a dog with seizures.
[00:24:56] Gómez‑Mejías: And the MRI seems to be the modality of choice for the brain, isn't it? But still, has the CT still a role in the diagnostic approach as well?
[00:25:08] Lowrie: Yeah, no, I mean, I think, I mean, MRI really is clearly preferred. MRI is by far and away the best tool for the subtle parenchymal disease of the brain. Things like inflammation and many of the lesions that we worry about in seizure in cats.
But CT, it still has a role when MRI isn't available and when maybe cost constraints are real for an owner, or when you're particularly suspicious of things that CT is relatively good at detecting, certain mass lesions, acute hemorrhage or bony change, it's got advantages. You know, it's quicker CT is much quicker and that sometimes matters in unstable patients or where anesthetic time needs to be minimized.
But the key practical point is, if we do a CT and it's normal, it doesn't rule out significant intracranial disease in a seizure in cat.
So you just need to frame expectations appropriately with the owners. If you're going down the route of CT, I think it's important they're informed and they then make the informed decision as to whether to do CT or MRI.
[00:26:13] Gómez‑Mejías: Yeah, because if you invest the money in an MRI and then you need. Sorry, in a CT and you still need to do an MRI later on and you need to pay for it, I guess that makes a huge difference to the ownership.
[00:26:27] Lowrie: It completely does. And that's it. I mean, I have no problems with performing CT of the brain. I just really wanted to know, to understand what the limitations are and it could give them an answer. You know, there will be times with. Hindsight's a great thing, isn't it? You know, you can look back and go, well, actually, a CT would have been perfectly appropriate. But I will be honest, the same practice, it's very rare. I will look back and say I'm pleased I did a CT over an MRI I think the vast majority of cases, the MRI gave a lot more information.
[00:26:56] Gómez‑Mejías: That's very useful to know. Thank you. There are other two tests that we tend to rely on, and that's the bloods. But you said in the review that the blood test results are often unremarkable. Is that even in metabolic screening, are there any other red flags apart from the bloods, which could point to metabolic disorders that we should be vigilant for?
[00:27:22 ]Lowrie: Yeah, I mean, I suppose it's true with the role I do, I will get cats come in that usually have had some blood tests and that first round of blood work is normal, but the first thing says, remember the tests. I mean, maybe the blood tests you'd perform on a cat might be different to the blood tests I perform and what another vet might perform.
So we all have our panel of chosen tests to run and there are probably strong similarities, but there'll be the odd one there that might be slightly different. And if you miss out a particular blood test, it's easy to overlook that and think, well, I mean, packed cell volume would be a great example. I think, to be fair, that's the one that's. If you're going to perform hematology, you probably get your hematocrit, your packed cell volume, but if you don't perform that.
That might be the only test you've got there of something like polycythemia, which is a definite cause for seizures in cats.
So it's very important about dotting the I's and crossing the t's when it comes to blood work.
And that's the first thing I'd say. But let's say we've done thorough tests and, you know, the blood work is normal, there are still clues that could help you keep metabolic disease on the radar. I mean, for me, the overall pattern of a metabolic cause for seizures would be kind of waxing and waning, systemic illness. So a cat that kind of has days when it's. Well, days when it's not so well outside of the seizures is important.
They might be a bit lethargic. You might have gastrointestinal signs, generalized weight loss, polyurea, polydipsia. And the one I mentioned earlier on, but really want to emphasize again, is hypertension - such a hard diagnosis in cats.
Partly because when you've just had one or two seizures, the hypertension may be very intermittent. And so ignoring all the practicalities of blood pressure measurement, you may be testing that cat on a day when the blood pressure is normal. But it's really repeated measurements that we want to check. And I think if you've got a cat with seizures where you've not found any other cause, so I suppose those where you're thinking idiopathic epilepsy is most likely, I would be keeping a very strong monitor on that cat's blood pressure and potentially get it in every six months, every three months for blood pressure monitoring.
But those clinical features for me matter as much as any single lab value. I suppose. Another. Is that some, well, I've said that some metabolic triggers can be intermittent. I mean, another example would be hypoglycemia. I mean, that is a good example. If it's episodic, a single normal glucose doesn't rule it out.
I would say this is far more common in dogs than cats, but it's definitely something to have on your radar with cats.
And then there are much subtler lab trends rather than these dramatic abnormalities. You know, these, you can imagine we get the blood test results where we've got these borderline electrolyte changes, maybe mild azotemia, poorly controlled hypothyroidism. I haven't mentioned that yet. I think that's important to bring up a huge one in seizure in cats or anything that suggests the cat isn't physiologically stable, even if the values aren't wildly outside the reference intervals.
So the red flags are often the history and the pattern rather than one sort of headline abnormality, if you like, on a single blood panel.
[00:30:46] Gómez‑Mejías: Thank you so much. You mentioned when you were talking about the bloods, you said something really interesting is that blood test will differ, will vary depending on the practitioner. And I remember having had this in practice, like this, this issue in the, in the past where I really, really wanted to check the bile acids to rule out to shunt after reading one of the JFMS clinical reviews where he said it was really important and then, and then the cat and the needed to be transferred to another hospital and that wasn't checked in the end and the, and the cat was put to sleep. And I was really upset because then I got the results and it turned out to be a high.
And then I said, well, there could have been a shirt there and stuff. So in seizures, is there any biochemistry parameter you would emphasize that you as a practitioner, I mean as a specialist and an expert in this matter, would you emphasize in particular.
[00:31:48] Lowrie: No, there would. I mean I could probably list quite a few. I mean obviously renal parameters. So urea and creatinine, vital liver enzymes are good on there. But you know what, they're not as important as you might think. So they're good there. But for liver, I'm most interested in the things the liver produces is what I'd say. So the four things for me would be glucose, urea, cholesterol and albumin. They're the four I would be really looking at when it comes to liver function.
But alongside that, I really do want that fasted bile acid test. I'm happy with that as a screen.
So postprandial are important, don't get me wrong. But I think if you've got a fasting bile acid in the first instance, it's very easy to do because you don't have to follow up with food and run it. But, but that would be important.
I'd also be looking at electrolytes and I've mentioned hematocrit, PCV. You know, I think that's a really important one in cats because it can be something that just, it can get overlooked is what I'd say. So, you know, you can, you can do hematology, but really check that value because if that's high, that could be everything you need to know about that cat. And you may have got a metabolic cause, but they're probably the general ones I'd be really wanting to make sure have been covered. And a fasted sample is the most important thing overall, actually, it's inevitable that when you see these cats in a clinic, they've come straight in having fitted and the owner wants an answer there and then, quite understandably. But sometimes some of these tests may just be better performed when the cat's been starved for, for a 12-hour period. Most cats have probably grazed leading up to that fit, which means that it's not a proper fasted sample and I don't have a problem with doing it then. But again, it comes back to owner information where as soon as they're informed, they may then go, you're absolutely right. Let's do these tests tomorrow. I'll keep the evening meal out of the way. I'll bring my cat first thing in the morning and we'll do these tests in a proper fasted state.
[00:33:41] Gómez‑Mejías: That's right. That's very, very, very helpful. Thank you so much. There's something very scary that it's getting sampling cerebrospinal fluid because it carries risks of damage to neural structures. Are there any specific contraindications and how do you recommend practitioners weigh the diagnostic benefit against the risks?
[00:34:03] Lowrie: Well, I want to start by saying spinal fluid analysis, when done well, is incredibly safe.
I think it's fair to say over the time I've done neurology, I've always had far more concerns with anesthetic than I have with spinal fluid collection. And I put that really into context that shows that really the risks of spinal fluid are fairly low.
Having said that, we need to look at when we shouldn't be performing it. And the absolute contraindication would be increased intracranial pressure. So especially if there's a large space occupying lesion or any evidence of brain herniation.
And that's why I always say imaging should come first.
If the MRI shows a mass effect, a midline shift, herniation or anything that suggests that pressure is raised, then a spinal fluid sample just isn't appropriate. And that's what makes me say that first statement, that in our hands, spinal fluid analysis is relatively safe. Not benign, but relatively safe.
But if imaging's normal or doesn't suggest raised intracranial pressure, then really it can be extremely helpful to collect spinal fluid. I always say MRIs find. This is how I speak to an RSA. MRIs find lumps and bumps.
It's not quite as good at detecting inflammation or indeed sometimes infectious disease. And that's where spinal fluid really comes into its own, that it allows us to make sure there aren't any inflammatory or infectious diseases going on. It may not give you a complete diagnosis of them, but it will at least tell you that there is something like that present. So the way I frame it is CSF is valuable.
It's not a standalone test. I'd never do it on its own. It's safest and really most informative when it's guided by imaging and by the clinical stability of the cap. Really, that's what I'd say about spinal fluid. Overall.
[00:35:59] Gómez‑Mejías: Thank you so much. And thank you for all the clarity we've gained around this topic today. Thanks to you and the way you communicate. Thank you so much.
I think that this brings us to the end of our discussion on the complexities of feline seizures. I'd say one of my takeaways is that a systematic approach and prioritizing a thorough history and clinical judgment is very relevant for an effective management.
No, not just the advanced techniques. And if you want to see the different seizure types we have discussed today, I highly encourage you to visit the Jounral of Feline Medicine and Surgery website to view the supplementary videos provided by Dr. Lowrie and his team. Thank you for listening.
We will be back again next month with more about feline medicine and the JFMS.
[00:36:52] Conclusion: Thank you for listening to this episode of All Cats Considered. We hope you enjoyed this interview. For more information on the topics discussed in this episode, please head over to catvets.com podcasts and explore the links in the show notes. Don't forget to subscribe to this podcast on your platform of choice so you won't miss any episodes as we release them. Have thoughts or ideas about the interview you heard today? Share them with us by leaving a comment on our Facebook page or shoot us an email
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