Which of these animals is most likely to have a 'trichobezoar '?

A trichobezoar is a bezoar (a mass found trapped in the gastrointestinal system) formed from the ingestion of hair. Trichobezoars are often associated with trichotillomania (compulsive hair pulling). Trichobezoars are rare, but can be fatal if undetected. Surgical intervention is often required.

A hairball is a small collection of hair or fur formed in the stomach of animals, and uncommonly in humans, that is occasionally vomited up when it becomes too big. Hairballs are primarily a tight elongated cylinder of packed fur, but may include bits of other elements such as swallowed food. Animals with hairballs are sometimes mistaken as having other conditions of the stomach such as lymphosarcoma, tuberculosis, and tumor of the spleen.

Cats are especially prone to hairball formation since they groom themselves by licking their fur, and thereby ingest it. Rabbits are also prone to hairballs because they groom themselves in the same fashion as cats, but hairballs are especially dangerous for rabbits because they cannot regurgitate them. Due to the digestive systems of rabbits being very fragile, hairballs in rabbits must be treated immediately or they may cause the animal to stop feeding and ultimately die due to dehydration. Cattle are also known to accumulate hairballs but, as they do not vomit, these are found usually after death and can be quite large.