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ACTH

A representation of ACTH

ACTH is the abbreviation for Adrenocorticotropic Hormone, a hormone produced by the pituitary gland. This hormone has the task of stimulating the adrenal glands to release cortisol, another hormone involved in many metabolic processes in the body.

Cortisol has many important functions, such as:

  • The regulation of blood sugar levels.
  • The support of the immune defense
  • The adaptation to stressful situations
  • The control of inflammation

When is ACTH used in dogs?

ACTH is used in dogs primarily as a diagnostic tool to determine if the adrenal glands are functioning properly. This is important to detect or rule out conditions such as Cushing's syndrome or Addison's disease.

Cushing's syndrome is a condition in which the adrenal glands produce too much cortisol. This can lead to symptoms such as:

  • Increased thirst and urine output.
  • Increased appetite and weight gain
  • Hair loss and thin skin
  • Muscle weakness and pancreatitis

Addison's disease is the opposite: the adrenal glands produce too little cortisol. This can lead to symptoms such as:

  • Decreased appetite and weight loss
  • Vomiting and diarrhea
  • Weakness and lethargy
  • Low blood pressure and shock

How is the ACTH test performed in dogs?

The ACTH test in dogs consists of two blood draws: One before and one after the administration of synthetic ACTH. The synthetic ACTH is administered either as an injection under the skin or as an infusion into the vein. The blood samples are then tested for cortisol levels.

The test is designed to show how the adrenal glands respond to the ACTH. If the adrenal glands are healthy, cortisol levels should rise significantly after ACTH is given. If the adrenal glands are overactive, as in Cushing's syndrome, the cortisol level should be very high even before ACTH is given and should barely rise. If the adrenal glands are underactive, as in Addison's disease, cortisol levels should be very low and barely rise.

What are the risks of ACTH testing in dogs?

ACTH testing in dogs is generally a safe and simple test that takes only a few minutes. Most dogs tolerate the administration of synthetic ACTH well and show no side effects. However, in rare cases, allergic reactions or infections at the injection site may occur.

The test may also give false results if the dog is taking other medications that may affect cortisol levels, such as steroids or phenobarbital. Therefore, the veterinarian should always be informed of any medications the dog is receiving.

The ACTH test is a useful tool to check the function of the adrenal glands in dogs. It can help diagnose or rule out conditions such as Cushing's syndrome or Addison's disease. The test is usually uncomplicated and safe, but in some cases can lead to complications or false results. Therefore, it should always be performed under the supervision of a veterinarian.


The authors assume that a veterinarian should be consulted if an animal is ill and that medication should only be taken after consultation with a doctor or pharmacist. Only an individual examination can lead to a diagnosis and treatment decision.

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