Is it true that ferrets get ill if they don’t have sex?

Strange as it sounds, yes it is! Or at least, it is true for jills (girl ferrets); the hobs (boys) don’t have the same problem. Until recently, if you kept ferrets you had two options – lots and lots of babies or no ferrets at all!

Unlike humans (or dogs or horses), ferrets are induced ovulators. This means that they won’t ovulate (release eggs from their ovaries) until they’re mated. The trigger for ovulation in ferrets is physical trauma to the neck (from the hob’s teeth where he bites her while mating) and the vagina (caused by the sharp barbs on his penis). In fact, the more trauma inflicted, the more eggs she releases, so the more kits (babies) she has.

The trouble is that (unlike cats and rabbits, who are also induced ovulators), if she doesn’t ovulate, her season won’t end on its own. It keeps going, and the longer it goes on for, the more oestrogen is released into the bloodstream.

Now, oestrogen is a great hormone, and is responsible for many female sexual characteristics as well as preparing the reproductive tract for fertilisation. However, in excess it’s really bad for a jill (or indeed any mammal), and can suppress the bone marrow, preventing it from making blood cells.

An unmated jill is sometimes described as having hyperoestrogenism. The symptoms are:

Constant oestrus behaviour – typically a swollen vulva and reduced appetite

Anaemia – insufficient red blood cells. The symptoms are: Pale gums Reduced ability to exercise or work Shortness of breath Lethargy

Panleukopenia – insufficient white blood cells, causing increased susceptibility to infection.

Thrombocytopenia – insufficient platelets (the cells that allow the blood to clot). This may result in: Blood in the droppings Bruising under the skin (visible as a rash) Internal bleeding

Baldness, as oestrogen at high levels stops the hair from growing.

What can be done to treat it?

The simplest solution is to allow her to be mated! There are also some medications that can chemically trigger ovulation, ending the season.

Yes, fortunately! There are five different options available for prevention of hyperoestrogenism in jills:

Allow her to be mated by a hob every season. Only go down this road if you can find homes for lots and lots of kits…

Allow her to be mated, but have the hob vasectomised. This is a simple operation where we cut the ducts that lead from his testicles, so although he can still mate her, he cannot get her pregnant.

Use a “Jill Jab”, an injection of devosterone that tricks her body into thinking it’s pregnant. The jab lasts about 4-6 months, but does have side effects (such as weight gain and sometimes loss of “work-ethic”).

Have her spayed – we do an operation and remove the jill’s uterus and ovaries. Obviously, she can never breed or come into season again. However, it does increase the risk of her developing other hormonal disorders (adrenal disease, or hyperadrenocorticism, which causes hair loss, rat tail, increased susceptibility to infection and alterations to thirst and urination).

Use the contraceptive implant (deslorelin). This essentially spays her medically for 18-24 months, without causing adrenal disease. As a result, it is now the most popular option!

If you want to talk about oestrus control or any aspect of ferret health, give us a call and talk to one of our vets.