The active period for the implant is from 8 mths to 4 years (Reported
in Australia).
Baldness is the least of the problems that may occur, it is known that
the hormones (estrogens/testosterone) can be can be elevated without
external symptoms and that when the disease does recur it often comes
back very quickly with the consequent risk of hyperplasia/neoplasia.
The general opinion seems to be to re-implant at 12 mths regardless. I
personally keep a close eye on my two for any signs at all from 8 mths
and have a new implant at 12 months, It is not expensive and even if
the original implant is still active no harm will be done with a second
implant (up to 10 times correct dose has been given to dogs with no
harmful effects).
Tony (not a vet), Sugar and Suki.
In memory of Sally and Sue.
[Posted in FML 6606]