If your dog is diagnosed with canine adrenal carcinoma, he has a tumor on his adrenal gland. The tumor is also known as a pheochromocytoma. If this tumor metastasizes, or spreads, it usually moves into the kidneys, liver or pancreas. Most canine adrenal carcinomas are idiopathic, meaning they have no known cause. Canines diagnosed with Cushing's disease, or overproduction of hormones produced by the adrenal glands, are more vulnerable.
Your dog's two adrenal glands lie close to his kidneys, with the right-side adrenal gland lying next to the vena cava, the largest vein in the body. These glands control the balance of water, salt and sugar in the dog's body, along with hormones such as cortisol. They control blood pressure, sex hormones in neutered or spayed dogs, and the immune system. Tumors occurring on these glands are often benign, or noncancerous. Both benign and malignant tumors in canines are relatively rare.
Symptoms of canine adrenal carcinoma include increased thirst and urination, panting and rapid breathing, weight loss, appetite loss, vomiting and diarrhea, pacing, hair loss, abdominal pain, lethargy and shaking. These symptoms might come and go, leading you to mistakenly think your dog is improving. As the disease progresses, dogs might experience seizures or collapse. Adrenal carcinoma usually affects dogs over the age of 7.
To diagnose, your vet physically examines your dog and takes blood and urine samples for testing. While tools such as ultrasound and computerized tomography scans can show your vet the tumor's location, determining whether the mass is benign or cancerous means actually biopsying the tumor. That requires surgery.
Surgery is necessary to remove the tumor, as well as the adrenal gland on which it is located. It's not an easy surgery, so you might want to consult a specialist rather than have your own vet perform the operation. According to VeterinaryPartner.com, removing an adrenal tumor is considered one of the most difficult surgeries in veterinary medicine. During the surgery, the vet might discover that the cancer has spread to other organs. If that's the case, parts or all of those organs require removal. Dogs already debilitated from Cushing's disease can take a long time to heal. Recovering dogs require various medications, including steroids. An affected dog might also undergo a chemotherapy regimen using the drug mitotane.
If the tumor is relatively small, less than 5 centimeters, and has not metastasized, your dog's prognosis is relatively good. Dogs recovering well from the operation live an average of about three years. Dogs with larger tumors, or with those that have spread, live an average of six months.
By Jane Meggitt
petMD: Pheochromocytoma in Dogs
Veterinary Partner: Adrenal Tumor Treatment
VCA Animal Hospitals: Adrenal Cortex Tumors
Vet Surgery Central: Adrenal Gland Tumors
The Merck Veterinary Manual: Hyperadrenocorticism (Cushing's disease)
About the Author
Jane Meggitt has been a writer for more than 20 years. In addition to reporting for a major newspaper chain, she has been published in "Horse News," "Suburban Classic," "Hoof Beats," "Equine Journal" and other publications. She has a Bachelor of Arts in English from New York University and an Associate of Arts from the American Academy of Dramatics Arts, New York City.