Adrenal Biopsy in Dogs

The adrenal glands are responsible for regulating the production a variety of hormones in the body. These hormones are responsible for controlling blood pressure, the immune system, stress levels and general metabolism of the animal. Dogs can suffer from a variety of problems that affect the adrenal glands. Most of these problems typically take the form of growths and in order for a complete diagnosis to be made, the vet will often have to take a tissue sample (via a procedure known as a biopsy) for further testing.

Usually, the dog will first be placed under a general anaesthetic in order to prevent movement during the procedure, which could cause the adrenal gland to move and the biopsy needle to miss. Next, if it has not already been done, an imaging scan will be done either via MRI or CT machines to verify the location of the growth. Next, the vet will insert a specialized biopsy needle through the dog's skin and into the targeted mass of tissue. At this point, an experienced vet may conduct the procedure using a freehand technique, going by feel alone. More often, however, the needle will be inserted and guided to the growth using an ultrasound machine. Once the needle is removed, the insertion point is cleaned and the tissue sample is placed in a sterile container for further analysis.

Testing of the tissue removed from the dog via biopsy can commonly be expected to take up to a week. Although a biopsy can be seen as somewhat invasive, it remains one of the most powerful diagnostic tools available for identifying diseased tissues. Once the test results come back, the vet will be able to make an informed decision when moving forward to the next stage of treatment and tailor it to the specific requirements of the individual dog's case. Oftentimes, it may be possible to make an accurate diagnosis by just using the results of MRI and CT scans. However, whilst using such non-invasive imaging techniques is preferable, there is at present no method that delivers the certainty of a diagnosis reached via a biopsy.

When the dog awakens from anesthesia, they may experience a degree of stiffness around the needle's entrance point. This will fade within a couple of days, and then the dog will be back to normal (aside from the symptoms associated with their underlying condition). Once the diagnostic process is complete, the owner will be required to return the dog to the clinic in order to begin treatment of the problem that is afflicting their adrenal glands. Sometimes, this can be a simple surgical procedure to remove the growth or - as is often the case with cancer - these visits will include courses of radiotherapy or chemotherapy.

The price of an adrenal biopsy can be as high as several hundred dollars. This is because of the specialized skills and equipment required during the testing of the tissue sample as well as during the procedure itself. By way of comparison, an MRI scan will cost over $1,000 to perform. An ultrasound scan, however, can run as low as $250.

As effective as the biopsy is as a diagnostic tool, there are a couple of risk factors that owners should be aware of before they have their pet undergo the procedure. The most obvious risk lies in the use of general anesthetic; while many younger dogs can be sedated relatively safely, older animals can suffer from heart or respiratory failure. The second and less obvious risk factor is the potential for a biopsy to unintentionally spread cancerous cells through the body by puncturing the tumor. Whilst this is dependent on the type of cancer involved, it is still a risk that some owners may be adverse to.

Unfortunately, most tumors and cysts found on the adrenal glands are at present thought to be due to genetic defects and not caused by environmental factors, making them virtually impossible to prevent. However, many tumors in general are caused by the ingestion of carcinogenic substances and a sedentary lifestyle. Owners can radically shrink the risk of such cancers by staying mindful of their dog's living environment and providing a good standard of diet and exercise.