Adrenal Tumors In Dogs

The familiar reference to adrenaline as the “fight or flight” survival hormone is a good indicator of how important an animal’s adrenal glands are. In addition to adrenaline, these small glands near the kidneys produce steroid hormones that regulate many of a dog’s organs, body systems and functions, including blood pressure. If the adrenal glands are not functioning properly, a dog’s health can be seriously impacted. Tumors are among various issues that can harm these glands — but, fortunately, adrenal tumors in dogs are rare. Only about 1% of dogs get them, and dogs that do typically are 10 years of age or older. Further, some tumors are benign, and some dogs can do well for long periods after treatment even if a tumor is malignant.

Types Of Adrenal Tumors In Dogs 

There are two primary types: 

Adenocarcinoma: A carcinoma is a cancerous tumor that originates in the skin or the lining of glands and organs. It can metastasize (spread) to other parts of the body.  If an adrenal carcinoma metastasizes, it typically will spread to the liver, lymph nodes, lungs and even into the major blood vessel near this organ.

Pheochromocytoma: Pheochromocytoma is considered a neuroendocrine tumor, meaning it originates from neuroendocrine cells. These are the cells that release hormones in response to stimulus from nerves. If malignant, pheochromocytoma in dogs can spread to the liver, lungs, the adjacent blood vessel or to the lymph nodes in the abdominal area.

Clinical Signs To Look For

An adrenal mass in dogs can impact hormone production. Thus, some of the symptoms that a dog might display are related to hormone imbalance. Symptoms can include:

• Lethargy
• Excessive panting
• Excessing drinking/urinating
• Hypertension
• Retinal detachment (as a sign of hypertension) and blindness
• Blood in the back of the eye
• Exercise intolerance
• Collapsing episodes (like fainting)
• Fur loss

Since other ailments can also cause similar symptoms, don’t presume your dog has an adrenal tumor if he or she is displaying these signs. In fact, adrenal tumors may even be found only incidentally — such as when a veterinarian happens to be performing an abdominal ultrasound for another reason. That’s why it’s important to have your veterinarian examine your dog before you come to the conclusion that he or she has a canine adrenal tumor.

Workup & Diagnosis

Diagnosing adrenal tumors in dogs relies on many of the same procedures that a veterinarian would perform for other types of tumors. Expect a physical exam, bloodwork/CBC (complete blood count) with a blood chemistry profile, urinalysis and  an abdominal ultrasound. Chest X-rays may be ordered to look for potential spread. Endocrine-specific tests may be performed to check for Cushing’s disease or other endocrine-related issues.  Your veterinarian might recommend a CT scan to further assess the adrenal region, assess for metastatic disease and assess for the feasibility of surgery. However, the only way to truly determine  whether a tumor is benign or malignant is with histopathology (a tissue sample).

Treatment Options & Prognosis

There are risks attached to treatment for adrenal gland cancer in dogs — and even for benign tumors.

Surgery: The treatment of choice is to surgically remove the affected adrenal gland. However, due to the location of adrenal glands and the possibility of a tumor entangling itself in nearby blood vessels, surgery is not without risk. There are occasions when surgery is not an option.  With surgery, the dog’s heart rate and blood pressure must be monitored very closely throughout the procedure, as death can occur intraoperatively or even in the recovery period post-surgery.  Thankfully, this is not too common.  Removal of a benign tumor can be curative. With the removal of a malignant tumor, a dog can do well for several months or even a few years, but there’s a chance the cancer will eventually return.

Stereotactic Radiation: This innovative treatment can now be used for adrenal tumors in dogs, which is particularly positive news if surgery is too risky. There is still risk with radiation, including a chance that death could occur. The goal of Stereotactic Radiation is to significantly damage tumors while sparing adjacent tissues and organs from harm. A typical protocol calls for one to three Stereotactic Radiation treatments. The PetCure Oncology team has extensive experience at providing Stereotactic Radiation. If treatment is successful, a dog can go back to enjoying his or her life for anywhere from several months to a few years. At that point, it’s possible the cancer may return.

Delayed treatment or no treatment: If an adrenal tumor is discovered incidentally rather than due to symptoms, a pet parent and/or the veterinarian may take a watch-and-wait approach. This could involve performing periodic ultrasounds to keep tabs on the tumor — perhaps one ultrasound every three months initially, then every six months if the tumor is not progressing.

If a smaller tumor is left untreated, it won’t cause a problem if it is benign or slow-growing. If the tumor is aggressive, however, a dog could experience the many symptoms and issues addressed earlier.

Find A PetCure Oncology Location Near You

PetCure Oncology’s mission is to help you care for your dog and give him or her the best quality of life possible for as long as possible. That’s why we provide innovative treatments for adrenal tumors in dogs and many other types of tumors. You will find that we are compassionate, supportive and professional at all times. For more information about PetCure Oncology and our treatment options, find a location near you today.