Effects of physical characteristics, behaviour, and medical conditions on a discomfort scoring assessment in shelter cats

Identifying pain and discomfort in cats is challenging; current methods mainly focus on pure pain scales in clinical settings. However, discomfort scales could offer a broader approach and could aid cat care in shelter facilities. The aims of this study were to validate a feline discomfort scoring assessment (DSA), to test reliability of the DSA, and to assess the effects of different medical conditions, cat characteristics and postures on DSA scores in shelter cats. Images from video recorded shelter cats (n=353) were extracted for DSA scoring, which assigns a score to different facial attributes up to a maximum of 10, with face shape (dolichocephalic, brachycephalic, or mesocephalic) and body posture also recorded. Additionally, cat age, breed, sex, coat length, body condition score (BCS), and any health conditions were recorded from individual cat records. Criterion and construct validity were confirmed for DSA. A very strong correlation existed between DSA total scores and the Feline Grimace Score total scores for 154 cat images (r = 0.85, P<0.001). Healthy cats (no medical diagnosis, no medication) also had significantly lower discomfort scores than Unhealthy cats (P<0.001). A very strong intra-observer reliability was documented (r = 0.89, P<0.001). ROC curve analysis identified that discomfort scores >3 indicate that caregivers should take action to safeguard cat welfare. Cats with low BCS (<3) had significantly higher discomfort scores than cats with BCS 4-9 (P = 0.002), older cats (11+ years) had significantly higher scores than other ages (P = 0.015) and male cats had higher total scores than females (P = 0.015). Lastly, cats sitting and standing had significantly lower discomfort scores than those in lying and crouching postures (P<0.001). Overall, the DSA was found to be a valid and reliable research tool for shelter cats, able to discriminate between cats that are healthy and those that are not. DSA also highlights groups of cats that may be at increased risk for discomfort, such as older and low BCS individuals, who need closer monitoring. Cat posture also appears to be a potential indicator of discomfort. There are some practical limitations of discomfort scoring in a shelter environment with larger cat populations; however, future research into automated methods should improve DSA practicality and ability to enhance cat welfare.