Can ovariectomy be justified on grounds of behaviour?

Clinical scenario

In practice, clinicians are commonly presented with mares reportedly behaving ‘badly’ either persistently or at regular or irregular intervals. This behaviour is often presumed by the owners or riders to be due to their mares being in oestrous or their reproductive hormone balance. Undesirable behaviour is varied and includes an unwillingness to respond to rider instruction or signals, bucking, rearing, overt reproductive behaviours, aggression and stallionlike behaviour [1–3]. It is assumed that when considering these behavioural problems, the behaviour in question has been confirmed by the clinician to be temporarily associated with the oestrus cycle or with ovarian pain and not musculoskeletal, soft tissue, gastric or dental pain. The question has been refined to exclude those behavioural issues experienced due to the presence of granulosa cell tumour (GCT; [3]). These criteria define the population of mares for the question, ‘can ovariectomy on grounds of behaviour be justified?’. The question is not an ethical one, rather whether or not behaviour can be improved with surgery.

Search strategy

Pubmed/Medline (www.ncbi.nlm.nih.gov/pubmed), the University of Liverpool electronic library search (www.liv.ac.uk.ezproxy.liv. ac.uk/library) and IVIS (http://www.ivis.org): ovariectomy AND mare AND behaviour. Hand searching of references in all articles identified and those within the author’s knowledge was conducted. In addition a request for references and opinions was made via a private worldwide equine reproduction e-mail network.  […]