Cats purr when they are happy, but they can also purr when sick or injured. The latter is not well known among cat caregivers. The  misconception that a purr always signals contentment could lead to a delay in medical care needed to alleviate the cat’s pain. We want to study if purrs from distressed cats are different from happy purrs.

It is generally assumed that cats who purr are content. However, limited evidence and anecdotes suggest cats may also purr when they solicit attention or food, and even when a cat is fearful, ill, or dying. Surprisingly, much is unknown about the function of the purr. The common claim that sick cats purr to heal themselves lacks evidence. This misbelief may result in cat guardians avoiding or postponing medical care for their feline companion, potentially not realizing the cat may be sending signals of distress. Misinterpretation of the feline purr may thus result in unnecessary suffering. These concerns illustrate the paucity of knowledge about the feline purr and stress the need for and importance of in-depth studies.

Here, we propose to analyse feline purr acoustics to determine the degree of variation in the purr within and between domestic cats, but also to identify possible differences in purrs in different contexts (i.e., happy and distressed). The long-term goal of this research is to generate data that will enable the development of a free app that would allow cat guardians to record and help interpret the purr of their cat.