A ferret being seen by a specialist vet
Breeding ferrets is a demanding undertaking and must be followed with the greatest care. It should be left to experienced or well-supported keepers, and never treated as a bit of fun. When something goes wrong, the speed at which the mother’s and/or the foetuses’ vital functions deteriorate is startling.
A female ferret (a jill) comes into season in the spring following the year of her birth. The month varies with light exposure. While most jills come into season in March–April, some can start much earlier, as soon as Christmas!
A markedly swollen vulva — about the size of a human little finger — together with a clear discharge are strongly suggestive signs of oestrus.
Mating
Mating is best done with an experienced male, especially for a first-time jill. It takes place 10 to 14 days after the signs of season appear. To improve the chances of conception, the pair can be left together for several days if need be, though this makes the due date harder to pin down. A first-time jill (pregnant for the first time) will give birth 41 days after mating, an experienced one 42 days. Knowing the exact due date is a real help in avoiding a prolonged pregnancy, which leads to a critical situation for the mother and the foetuses (which usually die soon after the due date passes).
After mating, the vulva should shrink and dry up within a few days. If it does not, fertilisation has not taken place. A return to season after 2 to 3 weeks points to a lost pregnancy.
Pregnancy
The smoothest possible pregnancy involves a few essential points to respect:
- Do not change the diet during pregnancy. Provide a high-quality food, rich in fat (18–20%) and good-quality protein (35–40%), before mating. The fat can be increased (up to 30%) after 3 weeks of lactation.
- Separate the male from the female. Otherwise the risk of post-partum cannibalism is very high.
- Keep an eye on the female’s health. She will gain weight and grow more tired as time goes on, but her urine should stay normal. From 1 month of pregnancy the foetuses can be palpated, which helps to tell it apart from a false pregnancy — an extremely common and very similar condition.
- Prepare the nesting box: a small nook the mother can leave (unless you are forced to keep her in with the kits) but the newborns cannot. Food and water close by. Suitable bedding that poses no risk of smothering.
Birth
The birth and the moments that follow are a delicate stage, especially if one crucial rule is broken:
Do not disturb her…! The mother tends carefully to the first newborns even before the birth is over, but will not stay put long enough to let them suckle.
Difficult births (dystocia) can happen but are rare (about 1%); most of the time the foetuses are numerous (around ten on average), and therefore small. The mother copes better if she is not disturbed while she works. Ideally, a good ferret owner does not know exactly how many babies are there in the first few days!
Dystocia is mainly a matter of passage problems, due to the size of the young or to abnormalities, of poor uterine tone, or of too few young.
It is best to watch the birth from a distance without stepping in too much (you pass on your stress and worry), to help if needed, or to ask the vet for help. A brownish discharge, a sudden halt in the middle of labour, or apathy should be counted among the warning signs.
After the birth and lactation
After the birth, the problems on the kits’ side are mainly strangulation from all the tangled cords, diarrhoea, and eyes that fail to open owing to conjunctivitis.
In the event of strangulation, one must sometimes resign oneself to sacrificing a newborn to free the others. The other problems call for a vet, and for a review of hygiene conditions.
The problems on the mother’s side are poor milk supply or a refusal to nurse (especially in first-timers), cannibalism, mastitis and metritis. Inflammation and infection require a vet’s intervention.
The quality of the food must be first-rate, and so must access to it. The male is kept away, even during pregnancy. If there are lactation problems, the kits’ best chance of survival is:
- to make the mother look after them (do not allow her out of the box). Give her privacy and quiet. If necessary, let her out to feed and then put her back with her kits. Watch the temperature — not too hot, but with a heat lamp partly covering the newborns.
- to find a foster jill (ideal in a serious crisis or if the mother dies, but very hard to arrange).
- to feed with puppy or kitten milk (3 parts) enriched with whipped cream (1 part). Before 3 weeks, the outlook for survival is extremely guarded.
Conclusion
Broadly speaking, it is impossible to spell out every last detail of this vast subject; you must do your homework thoroughly before deciding to breed from your jill.