How to Tell Male Ferrets From Females

Ferrets are known as jacks or jills, depending on sex. If you're purchasing a ferret from a pet store, don't assume the animal's indicated gender is correct. Generally, male ferrets are larger and more muscular than females, with bigger heads. Jills have a more delicate appearance, with thinner noses.

While basic physical appearance gives you clues, there's no substitute for the nitty-gritty of examining the ferret's abdomen, where you can make a definite call. You'll have to place the ferret on its back to get a good look, which can result in an angry animal. You might require an assistant to hold the ferret's upper body so you can hold the back legs and see clearly. If she is a jill, her abdomen is smooth, with no protuberance. With the jack, you might spot his testicles more easily than his penis. They're encased in a furry scrotum beneath his anus. His penis is inside his prepuce, a bump located on his abdomen's midline. You might notice urine stains in the area.

At approximately 6 months of age, jills mature sexually. Once female ferrets go into heat, their bodies produce very high levels of estrogen. Her genitals become very swollen. Until she breeds, the ferret remains in heat. A ferret remaining in heat for a month without breeding may develop bone marrow suppression and a marked anemia, which can kill her if heat isn't suppressed. Most jill de-sexing consists of spaying. However, if you plan to breed your pet in the future, your vet might be able to administer hormone injections to keep her from going into heat.

While the decision to neuter a male ferret doesn't have potentially deadly consequences of not de-sexing the female, it's still a very good idea unless you're a ferret breeder. Put bluntly, intact male ferrets literally stink. They're also more likely to become aggressive, attacking their owner or other members of the household. Your ferret's vet can neuter your pet when the animal is about 6 months old.