To Michelle concerning weight loss in breeding males:
 
>Can one of our esteemed vets tell me why whole male ferrets lose a lot of
>weight when they go into season????  Or is it just mine that do that?
>I have 5 unaltered males that will drop almost half their body weight each time
>they go into season.  One in particular goes down to almost nothing, and as
>soon as he goes out of season he'll gain it all back.
>Is there a biological reason for this? Maybe all those surging hormones? :-)
>And Is there anyway to stimulate their appetite during this time to keep
>this from happening? Any medication? An additive to their food?
 
        Michelle - the weight loss exhibited by males is not restricted to
ferrets, but occurs over a wide range of species.  Many things go into the
signalment for the beginning and end of the breeding season in animals including
the lenght of the sunlight hours, ambient temperature, etc., but by far, the
most important point, as you pointed out, is the elevated levels of ciruclating
testosterone.  the cells which produce this in the testis become very active and
increase in number during the breeding season, as does the size of the testicle
itself.  Testosterone has effects on cell sall over the body, and results in
numerous behavioral changes, including increased activity, aggression, desire to
want, and a decreased appetite.  All of these behaviors are desiigned to
increase tyhe reproductive effort of males.  A ferret that eats a lot will cover
less ground and impregnate less females.  So a key feature of testosterone is to
lessen the eating instincts.
 
        I have found that even castrated males have weight fluctuation during
the spring and summer months, although it is nowhere near as dramatic as with
intact males.
 
        As far as what you can do to increase appetite, I am somewhat at a loss.
I have yet to see anabolic steroids have much of an effect on ferrets, although
they will work in other species.  Perhaps my clincial colleague, Dr. Brown has
some comment along these lines....
       Bruce Williams, DVM                 Department of Veterinary Pathology
       [log in to unmask]         Armed Forces Institute of Pathology
       (202) 576-2453/2454                 Washington, D.C.  20306-6000
 
[Posted in FML issue 0904]