Testosterone may be analysed in
a single sample if the prescence of a whole testicle is suspected.
Where testicular reminants or incomplete castration may have
occured it is better to do the HCG stimulation test (listed
below).
HCG Stimulation
test
The hCG stimulation test may be
used to identify cryptorchidism or testicular function in virtually
any species.
The following procedure may be used as a guideline, the product
data sheet should be consulted for the exact dose required (*).
1. Take basal blood sample
2. Inject hCG i/v (Chorulon, Intervet) according to species:
3. Take a second blood sample 30 minutes to 2 hours later.
4. Label both samples clearly and request testosterone.
Interpretation
Animals who are castrated properly have low basal levels of
testosterone which show little or no increase in testosterone
levels following the administration of hCG.
Cryptorchids show increased basal levels of testosterone which
usually increase following the administration of hCG.
Animals with normal testicular function should have basal testosterone
levels within the relevant normal range and stimulate adequately
post injection of hCG.
Oestrone Sulphate
Test for equine cryptorchidism
(Rig Test).
Rig is a behavioural term used to describe a castrated animal
showing unexpected male behaviour. A true rig is an animal whose
unexpected male behaviour is confirmed to be due to testicular
tissue. A false rig is an animal whose unexpected male behaviour
is confirmed not due to testicular tissue.
Oestrone Sulphate is a single sample test to distinguish between
cryptorchids, true and false rigs. The Oestrone Sulphate test
is very accurate but any borderline results will need to be
confirmed using the hCG stimulation test.
NOTE:The
Oestrone Sulphate test must not be used in donkeys or animals
under three years old.
Oestrone Sulphate and the hCG stimulation
test should be used on any animals likely to be the subject
of any dispute or court case.
