Recognising feline pain: it's complicated!

This month our focus is on recognising feline pain. Yaiza Gomez-Meijas is joined by Beatriz Monteiro to discuss the feline grimace scale. Clare Rusbridge then joins Nathalie Dowgray to discuss neuropathic pain in cats.

Our episode begins with Yaiza interviewing Beatriz about her findings from a large bilingual global survey assessing if cat caregivers reliably assess acute pain in cats using the Feline Grimace Scale, an innovation that led to Monteiro winning the JFMS Best Resident Paper Award. The method allows both veterinarians and cat caregivers to evaluate pain based on facial expressions, aiming to bridge the gap between professional
veterinary assessments and at-home care for felines.

Nathalie is then joined by Professor Clare Rusbridge who shares insights into her recent JFMS article on Neuropathic pain in cats: Mechanisms and multimodal management. She highlights the importance of distinguishing between nociception and pain perception and discusses diagnostic challenges and management strategies for conditions like osteoarthritis and feline hyperesthesia syndrome.

For further reading material please visit:

Can cat caregivers reliably assess acute pain in cats using the Feline Grimace Scale?

The Feline Grimace Scale Website

Neuropathic pain in cats: Mechanisms and multimodal management

AAFP and ISFM Feline Environmental Needs Guidelines

Clare's Youtube Channel

For ISFM members, full recordings of each episode of the podcast is available for you to listen to at portal.icatcare.org. To become an ISFM member, or find out more about our Cat Friendly schemes, visit icatcare.org


Host:
Nathalie Dowgray, BVSc, MANZCVS, PgDip, MRCVS, PhD, Head of ISFM, International Society of Feline Medicine, International Cat Care, Tisbury, Wiltshire, UK

Speakers:
Yaiza Gomez-Mejias, LdaVet MANZCVS (Medicine of Cats) CertAP (SAM-F) Acr AVEPA, ISFM Community Coordinator and Small Animal Clinician

Beatriz Monteiro, DVM, PhD, ISFMAdvCertFB, PgDip, Chair of the World Small Animal Veterinary Association Global Pain Council and Winner of the 2024 JFMS Resident Best Paper Award

Clare Rusbridge, BVMS PhD DipECVN FRCVS, RCVS and European Specialist in Veterinary Neurology & JFMS Author

Creators & Guests

Host

Nathalie Dowgray

What is Chattering With ISFM?

Welcome to Chattering With ISFM, the official monthly podcast of the International Society of Feline Medicine, hosted by Nathalie Dowgray (Head of ISFM). Each month, we chatter about cats and cat-friendly practices with industry experts and contributors to The Journal of Feline Medicine and Surgery. Each episode contains highlights from our longer discussions and interviews, which are accessible to ISFM members at portal.icatcare.org. If you would like access to our full episodes, would like to become an ISFM member, or find out more about our Cat-Friendly schemes, visit icatcare.org.

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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