FERRET – JILL (FEMALE)

OESTRUS CONTROL

Jills are induced-ovulators. This means that they must mate before the eggs are released from the ovary.  This is quite unusual in the domestic animal.  Normally eggs are released regardless whether mating has taken place and these would only be fertilised and develop into a foetus post-mating..

Jills therefore have their own set of problems!  If they are not mated they can remain in oestrus (in season) for 4 – 6 months.  This invites a lot of trouble.  Apart from the vulva becoming traumatised, they lose a lot of weight.  More importantly the female hormone oestrogen, which is produced by the ovary while the Jill is in season, is a bone marrow suppressor.  Bone marrow produces blood cells so  Jills remaining in oestrus throughout the breeding season run a very severe risk of becoming anaemic - which could result in death.

OPTIONS:

There are a number of ways of preventing prolonged oestrus in the Jill;

·        Allow the Jill to mate and produce a litter;

·        Mate her with a vasectomised hob;

·        Give her a ‘Jill jab’. This is an injection of Delvosterone that will bring her out of oestrus for 5-6 months.  This is usually given near the beginning of her mating season and normally repeated annually;

·        Have her speyed. 

·        Give her a slow release hormone implant called Suprelorin every 2 years. This is now thought to be the best option.

SPEYING:

Performing an Ovario-hysterectomy means removal of both ovaries and uterus under a general anaesthetic.  This can be done in any Jill over three months old. However just before she is due her first season in spring, is better.  It does not matter what time of the year the operation

is carried out. Normally, this only involves the ferret spending a day at the surgery.  Although the initial outlay is more expensive than the ‘Jill jab’ or Suprelorin implant,  it is a one-off procedure.

Speying is an irreversible operation.  It will prevent her from accidental pregnancies and uterine infections.  [This is quite a common problem with older ferrets].

Speying can increase the risk of hyperadrenocorticism [adrenal disease] causing  the so called ‘rat tail’ and body-balding in older ferrets.

SUPRELORIN IMPLANTS :

Suprelorin is an implant licensed in the UK for use in male dogs. It has been used extensively in ferrets in Europe.

Suprelorin contains deslorin. This is a synthetic GnRH implant that binds to receptors in the pituitary gland, reduces the production of hormones that affect the adrenal gland and in turn the ovaries and testicles. Effectively this speys or castrates the ferret. It lasts for 18-24 months in ferrets.

Suprelorin is injected under the skin at the scruff of the neck. It has a wide-bore needle [like a microchip] and this is often performed more easily under brief gaseous anaesthesia while you wait at the surgery.

Nowadays Suprelorin is thought to be a better option than speying or castration, as neutering young ferrets will often cause an increase in adrenal activity.

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