Surgical neutering
Ovariohysterectomy ( spay ) is a surgical procedure in which the ovaries and uterus are removed . This should ideally be performed when the ferret is not in season , as there is an increased risk of bleeding if it is performed during a season . However , the author has experienced successful surgical neutering of jills in season .
Schoemaker et al . [ 5 ] have shown that there is a correlation between surgical neutering and the development of hyperadrenocorticism . This is thought to develop when high melatonin concentrations , for more than 12 hours per day , suppress the release of GnRH . When daylight increases , this suppression is lost and GnRH is released in a pulsatile fashion , resulting in the release of LH and FSH . These then stimulate the release of oestrogen from the ovaries . These hormones apply negative feedback on the hypothalamus and pituitary gland ( Figure 2 ).
Hypothalamus
Gonadotropin-releasing hormone ( GnRH )
Pituitary
Luteinising hormone ( LH )
Follicle-stimulating hormone ( FSH )
Negative feedback to suppress secretion of GnRH , LH and FSH
veterinary surgeons ( VSs ) will wait until a ferret reaches puberty before spaying . It is interesting to note that hyperadrenocorticism was also reported in seven sexually intact ferrets [ 5 ] , which suggests that many more intact ferrets with the disease may have gone unnoticed . Owners may not be aware of behavioural signs linked to the disease , such as sexual behaviour , as they may be considered normal in intact individuals , making the disease less likely to be reported to VSs .
An artificially prolonged photoperiod experienced by indoor pet ferrets , and a possible genetic component , may also be contributing factors to the development of hyperadrenocorticism . It is therefore advisable to house ferrets under natural lighting . More studies based in the UK are required to fully understand the prevalence of the disease in UK ferrets . The risk of developing hyperadrenocorticism should be discussed with ferret owners so an informed decision can be made .
The recent cost-of-living crisis may be having an impact on owners ' treatment decisions , as neutering incurs a one-off cost to the owner . Many VSs will perform the surgery based on an increased concern for ferret welfare . If the costs of alternatives are too great , then surgical neutering can avoid illness associated with prolonged oestrus in jills and avoid inexperienced breeding and unwanted litters .
In ferrets diagnosed with adrenocortical disease ( ACD ), a GnRH agonist deslorelin implant ( Suprelorin ) can be placed to treat the disease ( Figure 3 ). Suprelorin implantation appears promising as a treatment to temporarily eliminate clinical signs and decrease plasma concentrations of steroid hormones . Suprelorin may not decrease adrenal tumour growth in some treated ferrets , but the implants may be useful in the long-term management of hormone-induced sequelae in ferrets with ACD and those that are considered at surgical or anaesthetic risk [ 6 ] . Some authors even recommend it as a standard preventive treatment after neutering , in both sexes and for every ferret over 4 years of age [ 7 ] .
Ovary
Oestradiol
Figure 2 . The negative feedback loop operating to control the levels of reproductive hormones in unneutered ferret jills .
In neutered ferrets , this negative feedback is lost , resulting in an increased release of gonadotropins , which could cause steroidogenesis and induce nonneoplastic and neoplastic adrenocortical enlargement [ 1 ] . The ferret ' s age at neutering may be connected to the age at which hyperadrenocorticism develops , as a significant linear correlation has been detected between age at neutering and age at the time of diagnosis of hyperadrenocorticism , with the median interval being 3.5 years [ 5 ] . For this reason , many
Figure 3 . A female ferret presented in early oestrus for a Suprelorin implant .
48 Veterinary Nursing Journal