SCIENCE AND RESEARCH
Recognizing and managing acute pain with the Feline Grimace Scale©
We strongly advocate for feline welfare. Pain can only be treated if it is recognized. Over the past 10 years, we have worked on the development and validation of the Feline Grimace Scale©. We now have a strong body of evidence supporting the use of the FGS© by veterinary professionals and cat owners
The FGS© was carefully developed using robust methods and involving video recordings and image analysis of naturally painful and non-painful cats*. We measured specific angles and distances of key facial expressions as shown in the figures above.
* Cat owners signed an informed consent. Veterinary care was provided using cat-friendly techniques. None of the manipulations induced pain or harm to the cats.
​
Next Steps
Images of painful and pain-free cats were compared and five features were identified to be different between these cats. These features, called action units, include:
Ear position
Orbital tightening
Muzzle tension
Whiskers position
Head position
Validation
Rigorous scientific methods were applied to ensure that the Feline Grimace Scale© is valid for acute pain assessment
Acute pain
Measures what it is intended to be measured – in this case ‘acute pain’
Discrimination
Discriminates between different conditions (painful vs pain-free cats or before and after administration of painkillers)
Reliable today
Is reliable among different evaluators (similar total scores are given by different observers when scoring an image)
Correlation
Correlates with other similar valid pain scoring systems
Reliable also tomorrow
Is reliable over time (similar total scores are given by the same observer independently of the moment; for example today or next month)
Responsive
Detects response to treatment; scores reduce after analgesia
