Evaluation of collars and microchips for visual and permanent identification of pet cats.

To determine the percentage of pet cats still wearing collars and having functional microchips 6 months after application. Randomized controlled clinical trial. 538 client-owned cats. Cats were randomly assigned to wear 1 of 3 types of collars: plastic buckle, breakaway plastic buckle safety, and elastic stretch safety. Each cat was fitted with the assigned collar, and a microchip was inserted SC between the scapulae. Owners completed questionnaires about their experiences and expectations of collars at enrollment and at the conclusion of the study. 391 of the 538 (72.7%) cats successfully wore their collars for the entire 6-month study period. Owners' initial expectations of the cats' tolerance of the collar and the number of times the collar was reapplied on the cats' necks were the most important factors predicting success. Type of collar likely influenced how often collars needed to be reapplied. Eighteen (3.3%) cats caught a forelimb in their collar or caught their collar on an object or in their mouth. Of the 478 microchips that were scanned at the conclusion of the study, 477 (99.8%) were functional. Most cats successfully wore their collars. Because even house cats can become lost, veterinarians should recommend that all cats wear identification collars since they are the most obvious means of identifying an owned pet. For some cats, collars may frequently come off and become lost; therefore, microchips are an important form of backup identification. Owners should select a collar that their cat will tolerate and should check it often to ensure a proper fit.