TO: The Artificial Light Group
 
Your use of artificial lights to stimulate hair growth is interesting;
however, using artificial lights is not a new concept.  During the 1930's
several studies were done using artificial light to induce estrus cycles
(heat).  During the 1950's the neuropathways of light-induced estrus were
studied.  During the 1960's, 70's, and 80's the hormones and neuropathways
involved in reproductive neuroendocrinology in ferrets were studied.  I will
try to briefly explain this sixty plus years of medical research.  The
amount of light per day (photoperiods) regulates the amount of melatonin.
During the spring/summer months the photoperiod increases (13-15 hours of
light per day) and the melatonin levels decrease.  During the fall/winter
months the photoperiod decreases (8-12 hours of light per day) and the
melatonin levels increase.  Melatonin directly and indirectly controls the
hypothalamus-pituitary-adrenal/gonadal axis.  Thus the increased melatonin
levels (8-12 hours of light) cause the seasonal weight increase ends the
estrus cycles, and stimulates the hair follicles to grow hair (ie.  putting
on their winter coat).  Conversely the decreased melatonin levels (13-15
hours of light) cause the seasonal weight loss, starts the estrus cycles,
and causes the hair follicles to shed.
 
Based on your results, I suspect you are using a short photoperiod (8-11
hours) to increase the melatonin levels which is causing the hair growth and
weight gains.  However you are not actually curing these ferrets.  When you
increase the photoperiod (13-15 hours) estrus signs and hair loss will
re-occur and become progressively worse.  This same phenomenon occurs in
ferrets with early mild adrenal disease.  The use of artificial lights
(short photoperiod) or melatonin supplements to stimulate hair growth would
be best used 1) after adrenal surgery 2) when surgery is too risky (ie.
heart disease, lymphoma, etc.) 3) when the owner can not afford surgery , or
4) when the left adrenal gland has been removed and the right adrenal gland
has been debulked by capsular incision.
 
One last thing, the new canine drug Anipryl will not help adrenal disease in
ferrets.
 
Thank you
Jerry Murray, DVM
Animal Clinic of Farmers Branch
Farmers Branch,  Tx.
[Posted in FML issue 2107]