Perianal adenoma (growth on the anus and nearby) in Dogs
- Occurrence: common
- Location of disease: Abdomen/pelvis
When to visit the vet?
Non-urgent see a veterinarian within 2–3 days
If the condition worsens / symptoms persist, consult a veterinarian.
Definition
A perianal adenoma is a benign growth in the area of the anus or the surrounding skin in dogs. These tumors are common in older, unneutered male dogs and are related to the hormone testosterone.
BASICS/CAUSES:
Perianal adenomas develop from the sebaceous glands present in the skin around the anus. These glands are targeted by sex hormones, especially testosterone, and can grow excessively when these hormones are present in higher concentrations.
The hormonal dependence of these tumors explains why they occur more frequently in males than in females. These tumors are rare in neutered males and females, which highlights the importance of testosterone.
Genetic predisposition can also play a role, as certain dog breeds like Cocker Spaniels, Beagles, and Bulldogs have a higher predisposition for developing these tumors. This genetic component is an important consideration when it comes to breeding and selecting breeding animals.
The most important facts at a glance
Perianal adenomas in dogs are benign tumors near the anus that develop due to the influence of sex hormones, especially testosterone. They usually appear as flesh-colored, hairless swellings in the anal region and can cause itching or inflammatory conditions. Rarer symptoms include blood in the stool or weight loss. Diagnosis is made through a clinical examination, during which the vet palpates the affected region and, if necessary, takes tissue samples for microscopic examination to determine the type of tumor. Blood tests and ultrasound can also help with the evaluation. The primary treatment method is surgical removal of the tumor. For unneutered males, neutering is often recommended to lower testosterone levels and minimize the risk of recurrence. For dogs that cannot undergo surgery, drug treatments can be considered. The prognosis is generally good, especially with early detection and treatment. Neutering can significantly reduce the likelihood of recurrence. For prevention, neutering male dogs is recommended, especially if they are not intended for breeding. Regular check-ups and care of the anal region help detect changes early. Breeders should consider genetic predispositions to reduce the risk in future generations.
Causes
- Influence of sex hormones, especially testosterone
Symptoms
The most common symptoms of a perianal adenoma are visible lumps or masses around the dog’s anus. These lumps are usually round, smooth, and can vary in size from a pea to a golf ball. They are often well-defined and feel firm.
Other signs can include itching or irritation in the anal area, which can lead to the dog licking frequently or rubbing against the floor. In some cases, the tumors can ulcerate or bleed, which puts additional stress on the dog and poses a risk of infection.
Difficulty passing stool or changes in bowel movements can also occur, especially if the tumor is large and affects the anus or rectum. This can lead to constipation or pain during bowel movements.
Diagnosis
Diagnosis of a perianal adenoma usually begins with a thorough clinical examination by the veterinarian. The vet will take the dog’s medical history and examine the affected region visually and by palpation.
To confirm the type of tumor, a fine-needle aspiration or a biopsy can be performed. This involves taking cells or tissue samples from the lump and examining them under a microscope. This helps distinguish the adenoma from malignant tumors such as adenocarcinomas.
Blood tests can also be performed to assess the dog’s overall health and rule out other possible causes for the symptoms. In some cases, an abdominal ultrasound may be useful to check the internal organs.
Therapy
The primary treatment for perianal adenomas is usually surgical. Removing the tumor is the most effective method to relieve symptoms and prevent the tumor from growing further or ulcerating.
For unneutered males, neutering is often recommended, as removing the testicles lowers testosterone levels, which reduces the risk of the tumor recurring. This is especially important because the tumors are hormone-dependent.
In cases where the tumor cannot be surgically removed or the dog is not a candidate for surgery, drug treatments can be considered. Anti-androgen medications or hormone therapies can help slow tumor growth.
Prognosis and follow-up care
The prognosis for dogs with perianal adenomas is generally good, especially if the tumor is detected and treated early. Surgical removal often leads to a complete cure.
After neutering, the likelihood of the tumors recurring is significantly reduced. Even if the tumor cannot be completely removed, drug treatment can often control growth and improve the dog’s quality of life.
In rare cases, a perianal adenoma can become malignant, so regular monitoring is important. Dogs that have been affected should have regular veterinary check-ups to detect any recurrence early.
Prevention
The most effective prevention measure against perianal adenomas is neutering male dogs, especially if they are not intended for breeding. This significantly reduces testosterone levels and thus the risk of tumor development.
Regular examination and care of the anus and surrounding skin can help detect changes early. If a lump or swelling is suspected, the dog should be taken to a vet immediately.
For breeders, it is important to consider the genetic predisposition of dogs. Selecting breeding animals that have no family history of perianal adenomas can help reduce the risk in future generations.