Risks for Anal Gland Cancer in Dogs Age 7 & Older

Small senior terrier dog running happily through the grass

Anal gland issues affect over 3 million dogs a year, making them one of the most common pain points for dogs and pet parents. We might know what causes anal gland issues in dogs–digestive problems, allergies, obesity, and more–but what happens if we don’t get these risk factors under control?

As dogs age, it becomes more critical to actively support their anal gland health. Senior dogs are more vulnerable to advanced diseases and conditions, including anal gland cancer. We’ll explore the potential symptoms of anal gland distress, review the risk factors for anal gland cancer, and identify ways for pet parents to support their senior dog’s anal gland health. 

Anal gland cancer in senior dogs

Also known as anal sac adenocarcinomas or anal sac tumors, this type of cancer can afflict middle-aged to senior dogs. Some studies suggest that it’s more prevalent in older female dogs and that certain breeds–like the Alaskan Malamute, German Shepherd, and some Spaniels–may be more susceptible to the disease. 

In addition to being a risk factor for certain breeds, anal gland cancer can also be related to factors that include

  • Genetics
  • Parasites
  • Long-term obesity
  • A history of anal gland issues
  • Allergies (food or environmental)

Anal gland cancer is an extremely aggressive form of cancer, so early detection is essential! For senior dogs, health problems have higher stakes; if anal gland cancer isn’t diagnosed early, the prognosis can become more complicated. Tumors in one or more anal glands can be surgically removed, but if cancer has spread to lymph nodes surgery and recovery could become more difficult.

Signs of anal gland cancer in senior dogs

If you’ve seen the trademark symptoms of anal gland issues in dogs before, the symptoms will of anal gland cancer will sound familiar. If your senior dog (age 7 and above) has any of these symptoms, don’t wait––get them checked by your veterinarian! Senior dogs are at higher risk for developing serious complications if these symptoms go unchecked or untreated: 


Your senior dog will drag their butt across the floor to relieve painful pressure and itching from swollen anal glands.

Licking & Biting

Senior dogs might constantly lick the anal area in an attempt to soothe inflammation and itching. They may also appear to nip at their hindquarters or chew below the base of the tail where the pain is present.


Even if your dog isn’t prone to constipation, swollen anal glands can cause the anal cavity to narrow. This makes it more difficult for poop to pass through, leading to painful straining during bowel movements. 


If your dog is leaking poop or brown fluid between bowel movements, this could be a sign that the anal glands have become impacted. Full (impacted) anal glands will leak or ooze anal gland fluid between bowel movements if they aren’t being emptied naturally during bowel movements.

​​If your dog has any signs of bleeding or bloody discharge from their anal gland region, that could also signal a potential problem with the anal glands.


One symptom that’s more typical in anal gland cancer–as opposed to standard anal gland issues–is swelling around the anal region. In some cases, pet parents will be able to notice the swelling just by looking at their dog’s anus. 

It can be tough to identify the difference between typical anal gland issues and anal gland cancer. Because the symptoms overlap, it can feel impossible to know whether your senior dog is dealing with a typical problem or something more advanced. Only your veterinarian will know the difference!

Husky laying calmly on a clinic table as a veterinarian gives her an exam

How anal gland cancer in dogs is diagnosed 

The ‘big C’ is scary for any pet parent to hear. Early diagnosis means early treatment, and a better outlook for your dog––especially for senior dogs. So how will your vet determine if your dog’s anal gland issues are related to anal gland cancer? Here’s what to expect: 

Rectal exam

Many cases of anal gland cancer can be identified by your veterinarian through a rectal exam. They’ll gently palpate the anorectal area to feel for telltale lumps or lesions related to anal gland cancer.

Fine needle aspirate

If your vet suspects a tumor or mass is present, they’ll need to collect cells from the affected tissue. After sedating the dog, they’ll use a thin, empty needle to collect the cells. The tissue cells collected via fine needle aspiration will be processed in a lab to rule out or confirm a diagnosis of anal gland cancer. 

Additional testing

If pathogens are confirmed, your veterinarian may order additional blood work, tissue sampling (biopsy), ultrasounds, or x-rays to assess the extent of the disease. 

Oncologist referral

If anal sac cancer is confirmed, your vet will refer you to a veterinary oncologist (a veterinarian who treats diagnosed cancer in animals). A veterinary oncologist will determine the best treatment options for your dog and can connect you with resources to support you, your pet, and your family through the process.

How is anal gland cancer in dogs treated?

Most cases of anal sac cancer can be treated through surgical removal of the affected tissues, with post-surgery life expectancy lasting about 1-2 years. Additional testing from earlier in the diagnostic process will be crucial in figuring out if cancer has metastasized (spread to secondary locations) within the body. 

Pre-existing conditions or diseases can make the recovery process more difficult for senior dogs. Bradycardia (low heart rate), hypotension (low blood pressure), and hypoxemia (low blood oxygen) can all interfere with how well your senior dog handles the surgery and recovery stage. 

Even when treatment is successful, a diagnosis of anal gland cancer shortens your dog’s life expectancy. The good news? There are plenty of ways to keep your dog’s anal gland health on track throughout their life! 

Supporting your dog’s anal gland health at any age

It’s never too early to support your dog’s anal gland health! Supplementing their diet with gut-friendly ingredients, exercise, and more can all help you keep your dog’s anal gland health in check. 

Take a look at our checklist for anal gland health in dogs: 

  • Ensure your dog is getting a blend of soluble and insoluble fiber in their diet
  • Encourage regular exercise to improve digestion, regularity, and immune function
  • Always have clean, fresh drinking water available
  • Supplement with anal gland supplements for maintenance or advanced anal gland issues
  • Take your dog to the vet for manual anal gland expressions if necessary, but don’t rely on these as a ‘fix’ for underlying causes of anal gland issues
  • Identify and avoid any food or environmental allergies your dog may have
  • Treat seasonal allergy symptoms with supplements or allergy medication prescribed by your vet
  • Practice regular hygiene around the anal area 
  • Get immediate treatment for parasites
  • Report symptoms of anal gland distress or digestive irregularities to your veterinarian

There might be an expectation that advanced diseases often happen in older animals, but no pet parent is ever ready to be told that their pet has cancer. In most cases, this disease is preventable with regular veterinary check-ins, a balanced diet, and dietary supplementation when needed. Our last piece of advice? Your dog is never ‘too old’ to improve their anal gland health!