The effects of surgical and chemical castration on intermale aggression, sexual behaviour and play behaviour in the male ferret (Mustela putorius furo)

The ferret (Mustela putorius furo) has become an increasingly popular pet animal, yet little is known about their behaviour and welfare. Inter- and intra-specific aggression and the intense musky scent are the two main reasons why male ferrets are normally surgically castrated. However, it is this neutering that is thought to play an important role in the development of hyperadrenocorticism, a hyperfunctioning of the adrenal cortex due to neoplastic changes, a common disease in domestic ferrets. An alternative to surgical castration might be the slow releasing GnRH agonist deslorelin implant (chemical castration). The present study aimed to examine the effects of the deslorelin implant and surgical castration on the occurrence of intermale aggression, sexual behaviour and play behaviour in male ferrets. Therefore, 21 male domestic ferrets received either an implant containing deslorelin (n =7), a placebo implant (n =7), or were surgically castrated (n =7). Our data showed that: (1) chemical castration with the GnRH agonist deslorelin results in a decrease in the occurrence of aggressive behaviour between male ferrets both in the presence and absence of a receptive female. In addition, our data showed that a deslorelin castration had more effect on the reduction of aggression than surgical castration; (2) sexually motivated behavioural patterns were reduced in the deslorelin and surgical castrated group in the male-female confrontation; (3) the deslorelin group, and to a lesser extent the surgically castrated group, had a higher incidence of play behaviour in comparison to intact males in the intermale confrontation tests. Therefore, deslorelin chemical castration is a suitable alternative for surgical castration, and may even be preferred due to the serious medical problems associated with surgical castration in ferrets. Especially the increase of play behaviour might be indicative for an improved welfare of the ferrets.