The short answer is that we recommend neutering (castration for a hob and spay for a jill). Ferrets should be at least six months old before neutering so ideally wait until their first season to ensure that they are fully mature. The breeding season is roughly March to September. It is when the daylight hours increase and the temperature starts to rise. Hobs will come into season earlier, around December.
As a rescue we are only too aware of the large number of ferrets in rescues and therefore surgically neuter our ferrets before rehoming. This makes them better pets and prevents more unwanted ferrets being born and finding their way into rescue. Most ferrets coming into rescue are entire; either they have become unbearable to live with or they have escaped looking for a mate.
Leaving hobs entire: Hobs develop testicles, have a pungent smell, an oily coat and a keen desire to fight or mate other ferrets. This is particularly apparent during the breeding season. Other ferrets will be grabbed around the neck by the entire ferret who will be very determined to either fight off rivals or force themselves upon the other ferret. This means that they often have to be kept alone.
Leaving jills entire: Entire jills during the breeding season can be identified by the enlargement of the vulva. Jills remain in season until they are taken out by some method. Repeated seasons without being brought out by some method, if not immediately fatal, will have a drastic impact on life expectancy. This is because ferrets are induced ovulators and when in season hormones begin to build in the system. The oestrogen levels increase, affecting the bone marrow and a potentially fatal condition called aplastic anaemia can develop.
Breeding: There is no need for a ferret to have a litter prior to neutering. Anyone considering breeding their ferret needs to consider emergency vet costs, an increased food bill, more poop, a potentially large litter, nip training, being able to find reliable suitable permanent homes and much more. Mating is particularly rough in ferrets. The pregnant jill will need to be housed separately somewhere safe for the kits and you need to be prepared in case you have to hand rear. Litter size varies; the average is eight but we are aware of litters sizes ranging from one up to 21 kits. It is essential that ferrets are not bred from if you do not know if there are hereditary conditions which may be passed on.
Surgical neutering – castration (hobs): Neutering ferrets dramatically reduces the strong odour, the greasy coat and the desire to fight or try to mate other ferrets, whether in season or not. Before neutering wait until their testicles have descended as this makes operation easier. Castration removes the risk of testicular cancer and without the high hormone levels hobs are able to live with a group of ferrets all year round. In some hobs one or both testicles may fail to descend. It is thought to be a hereditary condition and therefore it is vital that these hobs are not bred from. Retained testicles have a high risk of becoming cancerous and so castration is essential. Castration is a one off procedure done under anaesthetic. It is easier during the summer as in winter the testicles are retracted back into the body. It is possible to start to see a change in behaviour after only one or two weeks, but allow four weeks before introducing to entire jills.
Surgical neutering – spaying (jills): The risks of leaving jills in season as already mentioned can lead to aplastic anaemia. Other common complications from not spaying a jill can be pyometra and ovarian cancers. Spaying is a one off procedure done under anaesthetic. Inexperienced vets may be unwilling to spay jills while in season whilst some will not neuter due to the perceived risk of adrenal disease. They may offer alternative options to neutering as mentioned below.
Vasectomy (hobs): A vasectomised hob is not neutered but has had the “snip” and can be used to bring a jill out of season through the act of mating. This is rough on the jill and may bring on a phantom pregnancy. Fully intact and vasectomised males both act and smell the same so will most likely need to be separated from other ferrets unless using to bring a jill out of season. A vasectomy is a one off procedure done under anaesthetic. Before a newly vasectomised hob can be used to bring a jill out of season, it must be confirmed that the vasectomy was successful. It has been known for vasectomies to fail or reverse, resulting in unwanted kits. A vasectomy must not be considered if the jills are related to the hob.
Jill jab: There is the option of a jill jab; a hormone injection given to an entire jill while she is in season. Understandably it can make her extremely hormonal and she may suffer from a phantom pregnancy. The jill jab needs to be given each breeding season however it is common for it to wear off, needing repeated injections during the year. The cost of the jill jab is getting increasingly more expensive so this needs to be taken into account. The jill jab does not remove the risk of pyometra or ovarian cancers.
Implant: It is possible to use a contraceptive implant (Suprelorin) as a chemical form of neutering. It is also used to treat the symptoms of adrenal disease should they occur (see below). An implant can be given alongside surgical neutering but it is effective on its own. The implant is expensive and takes six to eight weeks to work. The procedure is similar to injecting a microchip. Some vets may choose to give an anaesthetic. It can be given to both hobs and jills. Further implants will be needed if the ferret shows signs of coming into season, approximately every 12 to 24 months.
Adrenal disease: We do recognise that there is research, mostly conducted in the USA, concerning the link between neutering ferrets and the development of adrenal disease later in life. However this is based on American ferrets; they have very poor genetics due to mass breeding, are neutered at six to eight weeks old and mostly kept as indoor pets. Here at the rescue we do not neuter ferrets until they are fully mature (between six and nine months old) and have entered their first season to avoid the likelihood of adrenal disease.
As there is evidence to suggest artificial light cycles are a contributing factor, all of our ferrets are housed outside. some indoor ferret owners choose to implant. It is worth bearing in mind that implanting only helps with the symptoms of adrenal; it does not prevent it. Even entire (non neutered) ferrets can develop adrenal disease.
If you are still concerned about the risks of neutering please feel free to discuss it with us further. Whichever method you choose, please ensure that if your ferret is undergoing an anaesthetic that you do not starve your ferret beforehand.
All ferrets rehomed from the rescue that are old enough will be neutered. Young ferrets, not yet old enough to be neutered, will only be rehomed to experienced owners that we already know and will bring them back to us for neutering when they reach maturity.