Pain Assessment in Cats: Recognising and Responding to Feline Pain

Pain Assessment in Cats: A Critical Welfare Skill

Cats are notoriously stoic in expressing pain — an evolutionary strategy that minimises predation risk by masking vulnerability. This stoicism means feline pain is systematically underrecognised and undertreated, both in clinical settings and in the home. A growing body of research has developed validated tools for assessing pain in cats, and improving owner and clinician ability to recognise and respond to feline pain is one of the most important practical welfare advances in recent years.

Why Cats Hide Pain

Unlike dogs, who often vocalise and seek comfort when in pain, cats typically withdraw, reduce activity, and minimise conspicuous behaviour. The evolutionary logic is clear: a cat that shows pain signals is a vulnerable prey animal. This means:

Chronic pain may be present for months or years before recognition
Owners often attribute pain signs to "age" or "personality" rather than treatable conditions
Clinical examination underestimates pain when cats are anxious in the consulting room
Post-surgical pain is frequently undertreated because cats do not vocalise

Validated Pain Assessment Tools

Glasgow Composite Measure Pain Scale — Feline (CMPS-Feline)

A validated clinical tool assessing:

Vocalisation (growling, hissing, crying)
Attention to wound
Posture
Response to touch
Demeanour

Scoring enables standardised pain assessment and guides treatment decisions. A score ≥5/20 indicates the need for analgesia.

Feline Grimace Scale (FGS)

Developed at the University of Montreal — assesses pain through facial action units:

Orbital tightening: Squinting or partially closed eyes
Ear position: Ears flattened or rotated outward
Muzzle tension: Tense, rounded muzzle
Whisker position: Whiskers pulled back or bunched
Head position: Head below shoulder line

The FGS can be used from photographs — enabling remote assessment of pain for telemedicine consultations. A free app (FGS App) allows scoring with standardised guidelines.

Owner-Reported Chronic Pain Indicators

For chronic pain at home, the following signs provide important diagnostic information:

Changes in activity level — reluctance to jump, climb stairs, or access elevated areas
Changes in grooming — over-grooming a painful area, or under-grooming leading to unkempt coat
Changes in interaction — withdrawal, reduced interest in play, reduced head-bunting
Changes in litter tray use — reluctance to enter (posture pain), defaecating outside tray
Altered facial expression in resting — comparison to pre-illness photos is invaluable
Aggression when touched in specific areas — directional to pain location

Common Painful Conditions in Cats

Osteoarthritis: Affects 60–90% of cats over 10 years; primarily axial skeleton and elbows; chronically undertreated
Dental disease: Tooth resorption (idiopathic root resorption) causes severe pain; eruption of fractured teeth causes chronic oral pain
Chronic pancreatitis: Intermittent abdominal pain; often coexists with IBD and cholangiohepatitis (triaditis)
Interstitial cystitis (FIC): Severe bladder pain during flares; welfare emergency
Cancer: Many feline tumours cause pain inadequately treated in palliative care
Post-surgical pain: Castration, ovariohysterectomy, dental extractions — routinely undertreated

Pain Management Options for Cats

Meloxicam (Metacam): Licensed for cats; oral liquid; most evidence-based NSAID for feline chronic pain; requires kidney monitoring for long-term use
Robenacoxib (Onsior): Licensed for short-term pain; excellent safety profile for acute pain
Gabapentin: Neuropathic pain and anxiety; commonly used; safe at appropriate doses
Buprenorphine: Opioid; transmucosa administration; effective post-surgical analgesia
Environmental modification: Ramps, low-sided litter trays, heated beds — reduces pain from movement-related activities

Practical Guidance for Cat Owners

Learn the Feline Grimace Scale — keep a reference card or use the FGS app
Photograph your cat regularly — comparison over time detects subtle changes
If your cat seems "less like themselves" — withdraw, quieter, less active — pain is a likely explanation. Discuss with your vet
Do not give human pain medications to cats — paracetamol, ibuprofen, and aspirin are potentially fatal to cats