Reproduction of the Female Ferret (Mustela putorius furo)

Abstract

The domestic ferret is a seasonally polyoestrous species. Females reach puberty at the age of 8-12 months. Females exhibit a constant oestrus between late March and early August if they are not bred. Increasing tumescence in the pink-coloured vulva is a sign of pro-oestrus. Oestrus can persist for up to 5 months, but once ovulation is induced, either pregnancy or pseudopregnancy ensues. Follicular development and atresia overlap in such a manner that there is a recent cohort of follicles available for ovulation whenever copulation might occur. Copulation may last from 15 min to 3 h, the average being 1 h. Ovulation is induced by pressure on the cervix associated with copulation. After sufficient LH release, the pre-ovulatory follicles mature and an average of 12 oocytes (5-13) per female are ovulated 30-40 h after copulation into the ovarian bursa. The ferret oocytes are most capable of being fertilized up to 12 h after ovulation, i.e. 42-52 h after copulation. Ferret oocytes ovulate at the metaphase of the second meiotic division (MII) embedded in three layers of corona radiata cells. Embryos enter the uterus over a period of several days starting on day 5 after mating. Between days 12 and 13 after mating, the embryos have become implanted in the endometrium. Implantation in the ferret is central with rapid invasion of the uterine epithelium by the trophoblast over a broad area that eventually becomes a zonary band of endotheliochorial placenta. Gestation length is 41 days (39-42 days). The domestic ferret gives birth to an average of eight kits (1-18 kits), which weigh 6-12 g at birth.

Basic Anatomy, Physiology, and Husbandry

“…18,23,29 If ferrets are neutered before weaning, jills tend to become comparatively larger and hobs comparatively smaller, with a range of 0.8 to 1.2 kg for the two sexes. 10,14,22,29 Hobs typically reach puberty at about 9 months of age. Ferrets tend to gain weight as winter approaches and lose weight in the spring.…”

“…Ferrets tend to gain weight as winter approaches and lose weight in the spring. 22 In both sexes, fertility increases as the days get longer. 10,15 REPRODUCTION Jills normally reach sexual maturity at 8 to 12 months of age, usually in the first spring after birth.…”

Ovariohysterectomy in a domestic ferret (Mustela putorius furo)

“…Ferrets are long-day breeders and the breeding season extends from March through August in the Northern Hemisphere. In an appropriate photoperiod, ferrets reach puberty at 4-8 months of age (2). Estrus was diagnosed by observing vulvar swelling, with a vulva diameter of 1.6 cm (Figure 1-A) and by vaginal cytological examination.…”

“…Estrus was diagnosed by observing vulvar swelling, with a vulva diameter of 1.6 cm (Figure 1-A) and by vaginal cytological examination. The vulva being insignificant during the non-breeding season becomes enormous at estrus, and is the most obvious indication that a ferret is on heat (2). In the vaginal cytology of smear, >80% of epithelial cells were superficial cells, one fifth of which were fully keratinized.…”

“…In the vaginal cytology of smear, >80% of epithelial cells were superficial cells, one fifth of which were fully keratinized. In ferrets at estrus, superficial cells make up >90% of epithelial cells and these cells fully keratinize in several days (2). Estrus was further confirmed post-operatively by histological examination of the ovarian and uterine sections stained by a modified Mallory's triple staining technique (3).…”