Perianal Adenoma in Dogs: Causes, Symptoms, and Treatment

A perianal adenoma in dogs is a relatively common tumor, particularly in middle-aged or older dogs. “Perianal” refers to the area immediately surrounding the anus or termination of the digestive tract. Adenoma refers to a tumor that is not cancer. It starts in gland-like cells of the epithelial tissue (a thin layer of tissue that covers organs, glands, and other structures within the body). Perianal adenomas often occur in the sweat glands in this region. We also find these tumors on the foreskin, base of the tail, and groin. This condition primarily affects male dogs that have not been neutered, although female dogs can also develop perianal adenomas. As a responsible pet owner, it’s crucial to understand the causes, symptoms, and available treatment options for this condition to ensure your furry friend’s health and well-being.

Causes of Perianal Adenoma in Dogs

A perianal adenoma develops due to hormonal imbalances in dogs. Specifically, the presence of testosterone stimulates the growth of perianal gland cells, leading to the formation of benign tumors. For this reason, intact (unneutered) male dogs are more prone to developing perianal adenomas. However, it’s important to note that neutering does not guarantee complete prevention, as hormonal imbalances can still occur in neutered or female dogs.

Symptoms of Perianal Adenoma to Look For

Identifying perianal adenoma in dogs is relatively straightforward once you know what to look for. Common symptoms include one or more raised, rounded, and firm masses around the anus. These masses can range in size from small nodules (a growth of abnormal tissue) to larger tumors. They may be pigmented or ulcerated. An ulcerated cancer wound is when a cancer that is growing under the skin breaks through the skin and creates a wound. In some cases, perianal adenomas can cause discomfort or pain, leading to excessive licking, scooting, or difficulty with defecation.

Perianal Adenoma Complications

Although perianal adenomas are typically benign, they can occasionally lead to complications. The tumors may become ulcerated or infected, causing discomfort and potential secondary infections. Additionally, perianal adenomas can sometimes progress to perianal adenocarcinoma, a malignant form of the tumor. Therefore, promptly seeking veterinary attention is essential if you notice suspicious growths around your dog’s anus.

Treatment for Perianal Adenoma

The primary treatment for perianal adenoma in dogs is surgically removing the tumor(s). We typically perform this procedure under general anesthesia and remove the masses while preserving the normal anal tissue. In cases where the tumors are extensive or have become malignant, a more aggressive surgical approach or additional therapies such as radiation may be necessary.

Neutering, particularly in intact male dogs, is also recommended as it reduces testosterone levels and helps prevent the recurrence of perianal adenomas. Regular monitoring and follow-up visits with your veterinarian are essential to detect any recurrence or signs of malignancy.


A perianal adenoma is a common benign tumor that can affect both male and female dogs, although intact males are at higher risk. Here are some key points to remember:

  • While checking the perianal area of your dog may not be the most pleasant aspect of basic dog care, it is a necessary one. Identifying the characteristic raised masses around the anus is crucial for early detection and timely treatment.
  • Surgical removal, accompanied by neutering, remains the primary treatment option. 
  • By staying vigilant and seeking veterinary care, you can ensure your dog’s well-being and minimize the potential complications associated with perianal adenoma. 

We are passionate about helping you have a great and long relationship with your pet. Please don’t hesitate to visit our website for more educational information about pet care. Or call us to set an appointment for your furry loved one. 

Dr. Kim Stewart
College Hills Veterinary Hospital

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