Comparative Reproductive Systems in Exotic Species

What is the reproductive strategy of Ferrets?

Monoestrous reflex ovulators → egg released upon act of mating.
Ferrets come into season in response to increasing daylength (long-day breeders)

Failure of jill to mate can result in?

1. Prolonged production/secretion of oestrogen

2. Bone marrow suppression and subsequent anaemia

3. Death

Ferret must be mated or sham mated or given chemical oestrus suppression drugs (GnRH Agonists)

Describe the reproductive anatomy of the Hob/Male Ferret

Similar to the dog, major difference is J shaped os-penis. Testes small relative to body size. They are larger in size to females to avoid competing for resources.

Are ferret kittens born altricial or precocial?

Altricial

What is the reproductive strategy of a Myomorph rodent?

Large litter size, short gestation period and Altricial young

What is the reproductive strategy of a Hystricomorph rodent?

Small litter size, long gestation period, and precocial young

Compare the two types of female reproductive systems and label the relevent species

Bicornuate - Dogs, cats, Ferrets and Guinea Pigs

Duplex - Rabbits + the rest of rodents (single vagina with two cervixes that lead to separate uterine horns)

What types of ovulators are rodents?

They are all Poly seasonal, spontaneous ovulators, EXCEPT the Chinchilla which is only Poly seasonal (111 d length gestation and only two young per litter)

Describe the Accessory sex glands of the rodent penis

• Seminal Vesicles

• Prostate

• Coagulating gland

• Bublourethral gland

• Preputial Gland

In addition to Os penis

What is the most reliable form of sexing rodents?

Measuring anogenital distance. Testes can be retracted abdominally due to an open inguinal canal. Other differences include:

• Gerbil: Ventral scent gland more obvious in males with large testes

• Rats: Large testes - but can be neutered

• Guinea pigs: penis can be everted from prepuce

• Chinchilla: testes are often inguinal as no true scotum in male

• Mice: Only female mice have nipples

Describe how you would take a cytology sample of

• Flush vagina with 100μl of distilled water

• Air dry slide

• Stain (crystal violet/meth blue/diff quick)

• Count lymphocytes

• Count epithelial cells – do they have nuclei?

What is the Copulatory plug

Found following copulation in most female rodent
species. Thought to be congealed sperm, mucus and
accessory ejaculatory fluids, which harden within
the cervix

• Remains in place for 8-12 hours

• Often found on cage floor rather than in vagina!

What age are rodents typically sexually mature?

6-8 weeks, guinea pigs are 4-6 weeks.

How long is gestation typically in rodents?

Mice: 19-21

Rats: 21 -23

Hamsters: 15 - 18

Gerbils: 23 - 26

Guinea Pigs: 59 - 72

Chichillas: 111d