Hair balls in cats: a normal nuisance or a sign that something is wrong?

PRACTICAL RELEVANCE: Vomiting of hair balls is a common problem in domestic cats, to the extent that it is considered by many owners and veterinarians to be a normal feline behaviour. Whether this is ever the case remains unclear but in most shorthaired cats the frequent elimination of hair balls is an indicator of an underlying chronic disease that is causing increased ingestion of fur or altered gastrointestinal motility. Pruritic skin disease, flea infestation and/or an underlying dietary intolerance are common contributing factors that should not be overlooked. EVIDENCE BASE: Studies concerning this common problem are lacking and there are no previously published data regarding the incidence of hair balls in pet cats or potential predisposing causes. Although a range of commercial hair ball control diets are available there is no objective information in the public domain regarding their efficacy. Similarly, no studies have evaluated the success of other commonly recommended preventive strategies. CLINICAL CHALLENGES: Despite the lack of evidence-based information, veterinarians are faced with the day-to-day challenge of helping owners to limit the extent to which their cats produce hair balls. The problem is at best an unpleasant nuisance for both cat and owner, and at worst may be a cause of significant morbidity and even, in rare cases, mortality.