Nathalie Dowgray: Hello, welcome to the May episode of Chattering with ISFM.
I'm Nathalie Dowgray, Head of ISFM and host of this month's podcast.
First up this month, Yaiza Gomez Mejias is speaking with Beatriz
Monteiro, the recent winner of the JFMS Best Resident Paper Award.
The topic is, can cat caregivers reliably assess acute pain in cats
using the Feline Grimace Scale?
We're also featuring our monthly JFMS Clinical Spotlight interview, and this
month I'm speaking with Professor Clare Rusbridge about neuropathic pain in cats.
Yaiza Gomez Mejias: So in this award winning article, you and your
team investigated if cat caregivers can reliably assess acute pain
using the feline grimace scale.
So why did you choose this particular topic and would you
like to briefly mentioned what the feline grimace scale is?
Beatriz Monteiro: Since I have this beautiful cat lover audience, I would just
like to remind us all that pain should be, and it is, the fourth vital sign.
And once we systematically assess pain in every animal, we're going
to obviously start identifying these animals and then treating them, and
hopefully correcting this issue of under treatment and under diagnosis of pain.
So this is where the whole problem started.
And then the feline grimace scale came into play.
So it is a tool where you look at the cat's face and you look at
five different characteristics, which we call action units.
So this is, for example, the position of the ears, the opening of the eyes,
the position of the head, we also look at the muzzle and the whiskers.
So we look at these five action units and we give a score of 0, 1, or 2.
0 when it's normal, 1 when it's mildly changed or we're uncertain,
and a score of 2 when it's clearly changed from the normal.
So if you have five characteristics and you can give a score of 2 for
each, the maximum score of this scale is 10, and any cat that scores four or
higher, it means that they are in pain and we need to do something about it.
So for veterinary professionals, we're going to administer analgesics.
And for cat caregivers, they should be prompted to go and
take the cat to the veterinarian.
So this is what the feline grimace scale is.
We now have eight studies published on the feline grimace scale, and
we're understanding and doing all these studies and the limitations.
And we were very curious to know, since this is a very simple and quick
to use tool where you just need to look at the cat's face, you don't
necessarily need medical training.
You're just looking at changes in the facial expressions of
the cat and giving scores.
Could cat caregivers also be able to do this?Because if they can,
that would be amazing, right?
It means that in the home environment, they can evaluate their cat and help
them make decisions if they need to bring the cat to the vet, for example.
So initially we did a study where we invited five very dedicated cat caregivers
and they evaluated 100 images of cats with different degrees of pain and
they would give feline grimace scale pain scores on these 100 images and
they did that twice a few weeks apart.
And from that study, we found that they were reliable.
So those cat owners, they could evaluate pain in cats just
like most veterinarians will.
But then the question was, these five cat caregivers are very dedicated.
What about the average cat caregiver out there in the world?
Can we really say that any cat caregiver can do that?
So that was the purpose of this study that was awarded.
It was really like going global and trying to reach the average
cat caregiver population.
So that was really what we did.
So very briefly, we selected 10 images.
So remember in the first study we had 100.
We had to make this simple, otherwise no one would participate.
So we selected 10 images of cats from all of our previous studies.
And then we invited these people to score these cats using the feline grimace scale.
But they had to read the training manual that has all the images
of cats and the different scores.
And the survey was available in English and Spanish.
And it was online and it was free for anyone that could participate.
With a couple of eligibility criteria.
So we had to be over age and it had to be a cat caregiver to participate.
So a llong response to why we came to this study, but it really was a
journey trying to help understand how we can better evaluate pain in cats.
And then how can we transport all this information that we're
developing in the veterinary medicine world to the cat caregiver world?
Yaiza Gomez Mejias: Brilliant.
Thank you.
And it's such a helpful tool as well.
I think we all were very happy to have something that we could give caregivers
for them to monitor pain at home.
And can you summarize the results?
Beatriz Monteiro: Yes, absolutely.
So we were comparing the scores from cat caregivers and the
scores from veterinarians.
One thing where we did find the statistical difference between scores was
for the muzzle, the action unit muzzle.
And that was not surprising because in all of our previous studies,
we find that the muzzle is indeed the most difficult to score.
So that was really the only difference.
But the takeaway is that the feline grimace scale total
score was not different.
There were no difference in scores between veterinarians and cat caregivers.
And the other thing that we were actually very pleased to find was
that regardless of the demographics, there were no effect on any of
the demographics that we studied.
So we looked, for example, at the age of the participant, the gender, whether
they had worked in health medicine.
And whether they have previous experiences and none of the demographic variables
that we investigated affected scores, so we were very pleased to see that as well.
And I think what this translates to is that we can really extrapolate
that pretty much any cat caregiver is able to reliably assess pain in
cats using the feline grimace scale.
So I think it speaks to the widespread global representation and that
they're generally reliable to do that.
Yaiza Gomez Mejias: Fantastic.
So what would you recommend to those vets who are listening, who have never used
the feline grimace scale and would like to implement its use in their clinics?
Beatriz Monteiro: Well, go to felinegrimacescale.com We're close to
12 languages, so hopefully we can reach many veterinarians across the globe.
And in there, we have a lot of resources.
Print those resources and do like a session where everyone is scoring
these animals together and comparing these scores because I think this
generates very good discussions.
Nathalie Dowgray: And now I'm speaking with Professor Clare Rusbridge
about neuropathic pain in cats, pathophysiology, diagnosis and management.
So thank you so much for joining us today, Clare.
And we're going to be talking about your wonderful article for our
clinical spotlight series in JFMS on neuropathic pain in cats, the
mechanisms and multimodal management.
I was really keen to discuss why you think it's important that we
separately define nociception from pain itself and the experience of pain.
Clare Rusbridge: Thank you very much for having me.
So nociception is the process by which painful information is conveyed through
nociceptors, the receptors going up through the nerve into the spinal cord
and then conveyed up to the brain.
But the perception of pain is the brain responding to that information
and making cognitive decisions about it, having an emotional response to
it and perceiving that noxious insult.
So the two are really quite different.
You can have, for example, a withdrawal reflex, just a reflex,
after a painful insult to the foot.
So if we clamp artery forceps over a toe, that's the usual way of assessing that.
The foot can rreflexly withdraw even if the spinal cord is severed.
But pain perception is that information getting all the way to the brain and the
animal dealing with that information.
Nathalie Dowgray: Cool.
Now that's, I think, a really important definition to have, that
difference between the experience of pain versus the nociceptive response.
And sometimes I guess there's a neuropathic component within
a wider chronic pain issue.
How common is that to see in cats?
Clare Rusbridge: Very common.
We really have two terms I'd like to introduce, the first is nociplastic
pain and then we have neuropathic pain.
And the nociplastic is something that people possibly won't
have come across before.
And it's really to take into account how you can have altered nociception.
So altered pain information without any actual clear evidence of actual damage to
the nervous system or to the, the organ.
So a classic example of that in cats is cystitis, which I think
would actually be usefully called feline bladder pain syndrome.
So in this, we assume that there has been changes to the function of the
nervous system that is making this chronic pain syndrome much amplified.
So it's kind of central sensitization going on through the nervous system.
Another example, of course, is osteoarthritis, where the pain in that
condition is amplified by having different function to the nervous system through
the peripheral nerve, the dorsal nerve root ganglion and the spinal cord.
And that is distinguished from true neuropathic pain where there is
actually damage to the peripheral or the central nervous system.
So an example of neuropathic pain in the cat would be if they had orthopaedic
surgery and the surgeon retracted the sciatic nerve and kept that retraction
on for a long time and, give the sciatic nerve a little bit of a break if you
have to retract it and not leave it retracted over a long period of time.
So damage to that sciatic nerve can leave to postoperative neuropathic pain.
We know there's actually damage to that nerve going on rather than
a kind of theoretical concept.
The other term that we often use is maladaptive pain and that
really is another term for really describing nociplastic pain as well.
Nathalie Dowgray: Oh, that's fantastic and I haven't come across the nociplastic
pain definition really before, but actually, especially when I think about
osteoarthritis in cats, that makes a lot of sense that you've got the actual
joint pain, but often you've got this wider syndrome of other things going on.
And it does make sense to think about it in that way.
In terms of our diagnosis, how do we determine if a cat is
experiencing neuropathic pain?
Clare Rusbridge: We can really pinpoint it as having three
kind of arms for the diagnosis.
First of all, we need to show that there is a lesion or disease
affecting the peripheral nervous system or the central nervous system.
It's pretty easy if we have a good history.
So if we know that the cat had orthopaedic surgery and retraction of the sciatic
nerve, if we know that the cat was involved in a road traffic accident and
damaged the nerve roots going to the brachial plexus, then that's quite easy.
However, there are neuropathic pain syndromes, like, for example, feline
hyperesthesia syndrome, where if you did MRI, you would find nothing to
help you do those diagnostic tests.
So, that's just to say diagnosis can be very confusing in some cases.
So, the other sort of arm is, that's the first thing actually demonstrating
there is a lesion, the second thing is finding evidence of abnormal sensation.
So what that implies is there is an abnormal functioning in your system.
For example, in the cat with a damaged sciatic nerve due to orthopaedic
surgery, you may find that if you touch that area, they react really over
the top, or they may have numbness.
So it's one of the big ironies of neuropathic pain is that they
may have less sensation, but be experiencing abnormal sensation.
That would be one important facet.
And going back to that really challenging to diagnose case, the feline hyperesthesia
syndrome, those cats behave as if they're experiencing abnormal sensation.
Now, obviously that's trying to make a subjective assessment of a cat's
behaviour, which is very unreliable.
And then we have our diagnostic tests like MRI and electrophysiology.
Those may help, help confirm.
But of course, especially in this time of economic downturn and crisis where
people are managing cases on a budget or referral for those sorts of expensive
diagnostic tests isn't an option then I think it's reasonable to add in there
a positive response to trial treatment.
So if you have a high index of suspicion, perhaps a two week
course of trial treatment to see if there is a positive response.
Now, the negative side of that is that many of these drugs that we use
will affect the cat's emotional state.
And we've already talked about the connection between
the emotional state and pain.
And you could argue that in some of these cases, like feline hyperesthesia
syndrome, where a lot of the cats are dealing with anxiety issues, and
you think, are these signs related to stress rather than abnormal sensations?
And they make a response to a drug.
And you think, was that just them being more relaxed in their environment?
We don't know.
And some people would argue, does it matter?
We've got a happier cat, so maybe we've achieved the end
without actually knowing the why.
Nathalie Dowgray: I think that's a really good point and, and that role of, of
sort of the treatment trial, I think for a lot of us in general practice, when
maybe there aren't the funds available for, for some of the, the more extensive
diagnostics, it's nice to know that is also an option for us to be able
to take that route.And as I mentioned earlier, you had some really nice case
examples within this paper, which I
found, for me, really helpful to just interpret the text of what
you're saying and then how we would apply that into practice.
So, thank you so much for your time today, Clare.
Clare Rusbridge: Thank you very much.
Thank you very much for having me.
Nathalie Dowgray: Thanks for listening everyone.
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