Quirks and Quarks

Me-owch — could resting cat face tell us about kitty's pain?

Canadian scientists developed a "Feline Grimace Scale" to objectively measure acute pain in cats.

Canadian scientists developed a 'Feline Grimace Scale' to objectively measure acute pain in cats

This cat's owners suspect their cat, Marla, was crying in pain every night for over a year, until one day last fall she couldn't walk anymore and they had to put her down. (Amanda Buckiewicz)

Originally published on Feb. 1, 2020.

Assessing pain in cats is a notoriously difficult problem for vets. But if you have a cat experiencing pain, veterinarians now have a practical and scientifically validated tool that allows them to read a cat's facial expressions to understand how much pain it's in. 

"Cats when they come to the hospital they're anxious they're fearful. They tend to hide their pain-induced behaviours much differently than dogs," said Paulo Steagall, in conversation with Quirks & Quarks host Bob McDonald. Steagall is an associate professor of veterinary anesthesia and pain management at the University of Montreal.

Compared to dogs, cats are often under-treated for pain largely because previous tools developed for veterinarians to assess pain were extremely time consuming and therefore not practical.

To solve the problem, Steagall and his team developed and scientifically validated a "feline grimace scale."

Cats change their whisker position when they're feeling pain. (Paulo Steagall / University of Montreal)

Figuring out feline facial expressions of pain

The study, recently published in the journal Scientific Reports, involved video recording dozens of cats — with the owners' consent — that were brought into the University of Montreal's emergency and critical care unit of their veterinary hospital.

By comparing the video recordings taken prior to and after giving the cats pain relieving medication, scientists could measure the difference in the cats' facial expressions, which they then compared with healthy control cats, to create their new scale.

The scientists used the gold standard, yet time-consuming pain scale to assess how much pain the cats were experiencing when they were brought in, which scientists later compared to the Feline Grimace Scale. 

Steagall said they determined their new scale is "very reliable" in getting the similar results between observers, as well as compared to the gold standard assessment tool in assessing acute feline pain.

Five signs your cat may be in pain:

  • Ears rotated outward rather than forward
  • Squinted eyes
  • Muzzle tension resulting in a more elliptically-shaped face
  • Whiskers pointing toward cat rather than away
  • Head lowered below shoulders

Produced and written by Sonya Buyting