Adrenocortical Disease in Ferrets

Animal-Medicine

11401 NE 195th St. Bothell, WA  98011

(425) 486-9000 PHONE  (425) 486-9002 fax

www.theexoticvet.com

Adrenocortical disease is one of the most common health problems found in domestic ferrets in the United States. Affected ferrets develop nodular hyperplasia, adenomas, or adenocarcinomas in their adrenal gland(s). This abnormal adrenal tissue produces steroid sex hormones such as estradiol, androstendione, dihydroepiandrosterone, as well as their metabolites. An overproduction of these hormones leads to the common clinical signs of hair loss, itchiness, anemia, immunosuppression, muscle atrophy, hind limb weakness, insulin dysregulation, increased aggression, vulvar swelling (females), and prostatic enlargement (males). These symptoms can cause a significant decrease in the affected ferret’s quality of life. There are a number of potentially fatal health problems that can develop as a result of this disease, including urethral obstruction, bone marrow suppression, and tumor metastasis.

Affected animals are most commonly neutered, middle-aged to older ferrets. The prevalence of this disease in the American population of ferrets vs. the European population of ferrets has been linked to early spaying and neutering of pet ferrets in the United States. Almost all US ferrets are produced by “ferret farms,” which commonly neuter/spay all the ferrets they sell for the pet trade by the age of 6 weeks.

Any ferret suspected of having adrenocortical disease should undergo a full medical workup. This includes, but is not limited to:

  • Complete blood count to evaluate for anemia and/or bone marrow suppression
  • Serum chemistry to investigate systemic organ health
  • Steroid sex hormone assay to confirm the diagnosis of adrenal cortical disease
  • Ultrasound and radiographs to measure size of adrenal glands and examine the surrounding tissues for signs of metastatic tumors.

Ferret adrenocortical disease has been the subject of much scientific research. We have come a long way in our understanding of the disease, and there have been many recent advances in treatment. The following is a list of the best treatments currently available, as well as their pros and cons:

Melatonin

Ferrets that are treated with melatonin often regrow their hair, and show improvement in other clinical symptoms. However, studies have shown that melatonin treatment does not affect the abnormal adrenal gland tissue itself, and does not decrease the concentration of circulating steroid sex hormones. Relapse of symptoms within a few months is common in ferrets treated with melatonin alone. While melatonin treats the symptoms of adrenal cortical disease, it does not address the primary problem.

Leuprolide acetate (Lupron)

Lupron is a gonadotropin-releasing hormone (GnRH) agonist. It has been shown to eliminate or reduce the clinical signs associated with adrenal cortical disease in affected ferrets, and effectively decreases the production of steroid sex hormones. Studies have not yet proven whether or not Lupron affects the growth of adrenal tumors. Lupron is administered in the form of monthly injections. Long term studies are ongoing to determine safety of chronic Lupron administration in ferrets. At the moment, there are no reported safety concerns.

Deslorelin implants

Deslorelin is also a GnRH agonist; it works identically to Lupron. The main difference between the two drugs is dosing frequency. While Lupron requires monthly injections, Deslorelin implants have been shown to remain effective for 12-18 months, depending on the ferret. The Deslorelin implant is inserted in the subcutaneous tissues at the base of the neck, much like a microchip. Depending on the dose used and the stage of disease present, Deslorelin may affect growth of adrenal tumors. Some clinical findings suggest that ferrets receiving prophylactic, regular implantation with Deslorelin may not develop adrenal cortical disease. Further research needs to be done to evaluate long term effects of this implant. At this time, there are no reported safety concerns. Deslorelin remains one of the best treatments for adrenocortical disease to date.

Surgical removal of diseased adrenal gland tissue

Historically, this was considered the gold standard of adrenocortical disease treatment. If all of the abnormal adrenal gland tissue is surgically removed, the disease will not recur; however, this can be difficult to achieve, and requires an experienced surgeon. There are two adrenal glands, one on the left side of the body and one on the right side.   One or both glands may be affected by adrenal cortical disease. As with any surgical procedure, complications can occur. Surgical risks are minimalized with pre-surgical diagnostics and proper anesthesia monitoring.

Other medical treatments

Preliminary studies of GnRH vaccinations, which induce the body to produce antibodies against its own GnRH, have shown promise. This may eventually be used as a prophylactive treatment for adrenocortical disease. A GnRH vaccination has not yet been labeled as safe for use in ferrets.

Additional medications may be necessary to combat the side effects of adrenocortical disease.

 

March 30, 2015

Content of this Care Sheet Courtesy of:

The Center for Bird and Exotic Animal Medicine 

11401 NE 195th St. Bothell, WA  98011

(425) 486-9000 PHONE  (425) 486-9002 fax

www.theexoticvet.com