Spitz-like tail carriage in two domestic cats.

Domestic cats use visual cues to communicate with conspecifics and humans. This includes the position and movement of the tail. The tail up signal (i.e. tail held vertically with the tip curled) has been identified as a friendly greeting signal between cats and from cats to humans. We present here a report of two cats unable to display the classic tail up signal due to Spitz-like (curled) tail characteristics, a morphology not previously reported in the scientific literature. The cats, a British Shorthair (Mn, 2 y) and Domestic Longhair (Fn, 8.5 y), belonged to different households and were participants in a study of intraspecific social interactions. Video recordings show the cats displaying normal tail movements (waving, swishing, twitching) and position when the tail was hanging down. However, once the tail was raised to a vertical position, it immediately curled over the back. This Spitz-like tail posture was displayed both when greeting people and other cats. It had reportedly been present since adoption. There was no underlying medical history of injury or pain to indicate this was an acquired state. We suggest this Spitz-like tail is a spontaneously occurring anomaly, that does not seem to noticeably impair the cats' communicative abilities, as normal affiliative behaviours were observed during interactions with the cohoused cat. We discuss the significance of this finding in relation to the formation of social bonds and the signalling of affiliative intent.