What do humans, a tiny primate, and a type of dolphin have in common that is not shared by almost all other female mammals? I am sure you guessed correct when you said menopause. Females of these species, prior to the biological end of their lives, become sterile; they are "biologically spayed." This is a unique phenomenon in mammals; there are many instances where only a single female in the group will come into heat, but only in these few instances does the reproductive system actually "shut-down" (I have placed shut-down in quotes because that is not what actually happens, but in a general way, the usage is correct). Aside from the way the female was spayed (surgical v. genetic), the effects on the body are essentially the same. After menopause (or spaying), some minor masculation occurs, such as growing facial and body hair. Osteoporosis can occur, and there is usually some muscle loss. Early spaying has an insignificant impact on the final size of the female ferret, although other problems might be associated with the practice. While males of most species can undergo decreases in hormone production, none ever approach the finality of menopause. In most species, the male reproductive system works just fine, thank you, until death. None-the-less, the effects of traumatic or cultural castration are well known; they also involve the loss of muscle mass, retarded skeletal development (if castrated prior during development), and general feminization. The younger the individual at the time of castration, the more pronounced the results. Males undergoing very early castration can mimic female body size and proportions. If done at any time prior to skeletal maturity, castration will retard the final size of the male. There is no evidence that female ferrets undergo anything remotely similar to menopause; both female and male ferrets remain sexually potent their entire lives (although some with a somewhat diminished capacity). Both males and females may, as the result of some sort of pathology, stop producing hormones and become sterile, but such instances are not typical. From a BIOLOGICAL point of view, neutering a ferret is an invasive, unnatural process. So, aside from political and ecological issues associated with any pet, why neuter a ferret? Female ferrets are primarily neutered to prevent them from going into prolonged heat. Ferrets with a long term exposure to elevated levels of sex hormones lose the ability to produce adequate numbers of red blood cells, become anemic, and can develop infections or die. The problem for female ferrets is that they evolved as solitary predators; females exclude other females from their territory. Males do the same thing, but both males and females allow the opposite sex to share territorial space. It takes a lot of work to maintain a territorial limit; you have to constantly patrol the boundaries and poop in all the "corners" so ferret passersby know someone is at home. Also, it takes a lot of energy to ovulate, and for a small predator with high metabolic needs, it would be risky to shed eggs only to find the "guys" are not knocking at the door. So, a simple solution is delayed ovulation; the female goes into heat and just stays in the condition until a male stimulates the release of the eggs through courtship and intercourse. No male; no release of eggs, no lowering of estrogen level. Spaying stops all that, protecting the female. Males are castrated for other reasons. Like females, males go into a seasonal rut and become obsessed with sex (far worse than a teenage boy addicted to internet porn). During the rut, the male ferret produces a very strong scent, secreted in urine and body odor, and is instantly recognized by other males and females. Females are attracted to this odor (and some research suggests they will go into heat faster when exposed to it), as are other males in rut. Why males? Because sometimes the best way to get a female is to steal her from another male. If you think some dominance fighting between ferrets is bad, watch two rutting males go at it. Nasty, and sometimes, quite deadly. There is no evidence a whole male is more aggressive towards their owner compared to a castrated one; having owned both, I have seen differences towards other ferrets, but none towards myself. Some data suggests males live longer if castrated because the lowered testosterone reduces physiological stress, but I do not know of such a study in the ferret. It is pretty obvious neutering a male ferret protects the furniture. And shoes. And anything else remotely resembling a female ferret (even some things that do not). The real controversy about neutering is the age at which it is done. Ferrets sold through large breeders, like Marshall Farms, are neutered before shipping to pet stores. Since these kits are marketed between 7 and 8 weeks of age, it means they are neutered prior to that time. This has at least one major (and obvious) result; early neutered male ferrets are significantly smaller than late neutered ferrets (but both are still larger than females). Neutering a male ferret during it's growth phase reduces the influence of sex hormones on the final size of the bones. Smaller, shorter bones translates as smaller, shorter males. While I have been able to statistically prove this causal link, a smaller size has no direct relationship with quality of life. The real question is, does early neutering cause other problems? Well, maybe. Maybe not. Certainly, there is a lot of evidence that suggests major physiological changes occur upon the cessation of sex hormones, and some of those CAN be bad (such as osteoporosis or some neurological changes). But are there others that can be causal-linked to early neutering? Not really. It is true that some research SUGGESTS a link between early neuters and some endocrine disorders, but that link hasn't been proven for any disease in ferrets. And while I might SUSPECT some sort of relationship between adrenal disease and early neutering, I cannot prove it it actually exists, and as far as I know, neither can anyone else. HOWEVER, neutering is certainly a source of physiological stress, so it potentially can act as a trigger for age-related environmental disease. More research is necessary. 1) Try to neuter your ferret, especially the males, AFTER reaching their adult peak. This should be about 11 to 13 months, but you can tell because they don't get LONGER or TALLER (they still can get bigger--mostly from increased muscle mass). This is NOT necessarily when they go into heat or rut for the first time; that can happen several months before or after reaching their growth peak. 2) Speak intelligently and politely to pet stores about early neutering. If you have a late neutered male, show them the difference. Suggest alternative sources for late-neutered ferrets, if you know of any. Did I say to be polite? Bob C and 16 Mo' Culturally Neutered Gingriches [Posted in FML issue 2979]