HCG Stimulation Test

• Detection of endocrine active tissue of the gonads (ovary, testis).
• Suspected ovarian remnant syndrome (dog)
• Clarification of cryptorchidism

Serum 2x 0.5 ml

Dog (male/female), male cat, stallion:

• First blood collection = baseline value (testosterone: male dog, male cat, stallion or oestradiol in female dogs)
• Injection of HCG:
  Dog/mal cat:: 500 IU of HCG/animal i.v.
  Horse: 5000–10000 IU of HCG/animal i.v.
  Donkey: 6000 IU of HCG/animal i.v.
• Second sample after 1 hour (male cat: after 2 hours) = stimulation value
• (dog: an additional blood sample may be taken after 30 minutes)

• First blood collection = baseline value (testosterone)
• Injection of 250 IU of HCG/animal i.m.
• Second sample after 1 hour = stimulation value

• First blood collection = baseline value (progesterone)
• Injection of 250 IU of HCG/animal i.m.
• Second sample after 5–7 days = stimulation value

Dog, cat, horse: testosterone (male) or oestradiol (female)
Rabbit: testosterone (male) or progesterone (female)
Horse/donkey: testosterone

Chemiluminescence assay (CLIA);
Horse, donkey, rabbit: Liquid chromatography-mass spectrometry (LCMS)

Dog, cat, rabbit, horse, donkey

Female animals:
Reporting of results on the day the sample is received (Mon–Sat),

Male animals: Dog, cat: Reporting of results on the day the sample is received (Mon–Sat);
Rabbit: 2–4 working days

• In most cases, the determination of the AMH level (see category Endocrinology / Tumour Markers) provides comparable information.
• Male dog: Post-stimulation testosterone concentrations > 1.0 ng/ml indicate that there is testicular tissue.
• Rabbit: Stimulation values of > 1 ng/ml of testosterone or > 4 ng/ml of progesterone indicate hormone-producing tissue.
• Stallion: A significant increase in testosterone would prove the presence of testosterone-producing tissue. Borderline results can be further clarified by determining the Anti-Müllerian Hormone (AMH).

• The HCG Stimulation Test (as well as the GnRH Stimulation Test with the test number 2281) can be used to detect endocrine active ovarian tissue / ovarian remnant syndrome in female dogs. It is a determination of oestardiol. The stimulation of oestradiol secretion is strongly dependent on the cycle status. Significant increases in concentration are expected in the oestrus and late anoestrus.