Behavioural indicators for cats’ perception of food: A novel tool for development of veterinary pharmaceuticals

Administering oral medication to cats isoften challenging to owners. Cats have a strong aversion to swallowing objects theyperceive as non-food, and voluntary consumption of veterinary tablets by catsis typically below 50%. The pharmaceutical industry has recognised the need to developveterinary pharmaceuticals with a more acceptable smell, taste, size and consistency,but development is hindered by lack of research methods capable of detectingsubtle differences in cats’ perceptions. Such methods are needed to determine whichof the formulations under development are less aversive than others, so thatthey can be selected for further improvement. Existing palatability tests are basedon the less informative dichotomous measure of whether the cat eats a tablet ornot and on assessments by cat owners, which are subject to bias. Behaviouralindicators offer a promising window to more detailed information on cats’perceptions. A set of behavioural indicators has previously been determined fortwo degrees of palatability of cat foods. The aim of this study was to identifyan expanded set of behavioural indicators to measure subtle vs. substantial degreesof palatability. A total of 34 pet cats were used in the study. The cats werepresented with three types of edible items, one at a time: favoured food (FF),favoured food with a placebo mini-tablet (TFF) and non-favoured food (NFF). Theitems were presented in a pseudo-randomized sequence, six trials per item, 18trials per cat, over a period of two days. Behaviour of cats before, during andafter eating or refusing to eat was recorded on video. Two trained observersindependently determined the prevalence of 16 behavioural patterns on the videorecordings, blinded to the types of edible items. The data were analysed with amixed logistic regression model. The following behavioural patterns were found tobe more prevalent with NFF than with FF: a rapid ear flick backward (OR 12.6, P<0.001),a lick on the nose after not eating the item (OR 80.2, P<0.001), flicking ofthe tail (OR 7.3, P<0.001) and grooming of the body (OR 1.8, P<0.05). Forthe subtle difference between TFF and FF, the most promising indicator was the moreprevalent dropping of food from the mouth while eating TFF (OR 2.0, P<0.001). These findings provide evidence of new behavioural indicators forobjective assessment of food perception in cats. They have practicalapplicability in designing a novel palatability test for developing veterinarypharmaceuticals with improved palatability for cats.