ACTH Test for Dogs

The ACTH test is an analysis that may be used to asses the function of the adrenal glands, which are part of the endocrine system. ACTH stands for the adrenocorticotropic hormone which is normally secreted by the pituitary gland and is meant to stimulate the production of cortisol and aldosterone in the dog’s body. The test may be helpful in diagnosing diseases such as Cushing’s disease or Addison’s disease or other adrenal insufficiency diseases. The ACTH test is essential, as adrenal insufficiency diseases may be dangerous for the dog’s health.

The ACTH Test

The ACTH test is performed by injecting a reduced amount of synthetic adrenocorticotropic hormone into the dog’s body. The dog is then tested for reactions and the amount of cortisol and aldosterone produced by the body in response to the injection. After the injection, the vet will measure the amounts of cortisol and aldosterone.

The results of the test will help the vet determine if the condition of the dog is determined by an adrenal deficiency (insufficient production of cortisol and aldosterone) or the dog has a pituitary gland deficiency (a low production of adrenocorticotropic hormone).

Variations of the ACTH Test

The ACTH test may be performed in several ways including:

  • A low dose test, a short test that takes up to 1 hour
  • Normal dose short test, is similar to the low dose test, giving similar results
  • Long conventional dose test or prolonged stimulation test, can be performed throughout 24 or 48 hours and will determine the degree of adrenal insufficiency, but is less frequently performed, as the short tests may provide the necessary information to diagnose the dog

The vet will establish which variation of the test is more suitable for your pet, depending on the conditions that the vet suspects and based on the levels of hormones in the dog’s body.

How to Prepare the Dog for Testing

Before the ACTH test, the dog must fast for at least 8 hours, so that the results will be conclusive.

The dog should discontinue any corticosteroid medication or adrenal extract supplements, as these will influence the results of the test.

Interpreting the Test Results

The vet will be able to interpret the test results, based on the production of cortisol and aldosterone. The normal levels of these hormones may vary depending on the dog’s breed, age and sex.

ACTH Test Side Effects

The side effects of the ACTH tests in canines may include:

  • Nausea and vomiting
  • Elevated body temperature
  • Itchy and irritated skin
  • Irregular heart beats
  • Impaired vision
  • Sudden collapse, in rare cases
  • Breathing problems

The injection site may also get swollen and red and some more sensitive pets may develop an allergic reaction.

The side effects may be present for a few hours after the administration of the synthetic adrenocorticotropic hormone.