Can you tell if a cat is in pain by looking at him? Probably not. Fortunately, researchers are close to changing that, a development that will be helpful in animal shelters, veterinary hospitals and homes alike.
First, the bad news: Of 68 observers in a recent study, only 13% were able to tell the difference between cats in pain and cats who weren't in pain 80% of the time.
The good news is that researchers were able to quantify those differences and render them in a simple cartoon-style drawing that enabled reliable identification of painful cats:
Analysis of 78 facial landmarks and 80 distances identified six significant factors differentiating pain-free and painful faces including ear position and areas around the mouth/muzzle. Standardised mouth and ear distances when combined showed excellent discrimination properties, correctly differentiating pain-free and painful cats in 98% of cases.
More good news: the complete study can be rented for 48 hours for only $4.00 at the link below.
Holden E, Calvo G, Bell A, et al. Evaluation of facial expression in acute pain in cats. J Small Anim Pract. 2014 Dec; 55(12):615-621.