Other health problems

Skin Tumors on Dogs

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. Updated: September 27, 2017
Skin Tumors on Dogs

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Skin tumors are among the most common skin diseases in dogs. Skin tumors that occur in the skin itself (in the epidermis or the dermis) and are called subcutaneous tumors and develop just under the skin.

Strictly speaking, a tumor is a prominent, hard and well-defined lesion. On the other hand, a neoplasm is tissue overgrowth, which does not match the growth of other body tissues. However, in practice both terms are used interchangeably.

In this AnimalWised article we will explain the different types of skin tumors on dogs that exist, what the symptoms are and the most common treatments. Keep reading:

  1. Types of skin tumours on dogs
  2. Causes and risk factors
  3. Symptoms
  4. Diagnosis
  5. Treatment
  6. Prevention

Types of skin tumours on dogs

Malignant skin tumors grow quickly and can spread to other parts of the body (a process known as metastasis), damaging other organs and even killing the dog. Instead, benign tumors can cause some discomfort but usually do not cause serious damage.

There are many forms of tumors and skin tumors in dogs, but some of the most common are:

  • Perianal adenoma
  • Haemangioma
  • Haemangiosarcoma
  • Lymphoma
  • Lipoma
  • Melanoma
  • Papilloma
  • Basal cell tumour
  • Apocrine gland tumour of the anal sac
  • Canine transmissible venereal tumour

Causes and risk factors

The causes are varied. Skin tumors can be caused by infections, cancer or simply by the accumulation and compaction of fat masses under the skin.

Environmental factors may play a role in tumor development, but genetic factors also play a fundamental role. Many dog breeds are prone to develop skin tumors and skin malignancies. These breeds include:

Skin Tumors on Dogs - Causes and risk factors


The symptoms vary depending on the type of tumor, but in general they will cause prominent masses of tissue such as protruding lumps you can feel from touching the dog or noticeable to the naked eye. Common symptoms of skin tumors are:

  • Nodules, whether rounded or cauliflower-shaped.
  • Pedunculated masses pushing on the skin (i.e. they have a stem).
  • Lumps covered with scaly skin, or on bare skin.
  • Bleeding or ulcerated nodules or bumps.


The diagnosis is established through cytology and histopathology tests on a sample of the tumor.

The sample can be taken through a fine-needle aspiration (using a syringe) through a slide (only in some tumors) or through a biopsy.

Although the veterinarian may be very experienced, it is necessary to perform laboratory studies to confirm or rule out the presence of a tumor or neoplasm, and to know for certain if it is a malignant or benign formation.

Only the veterinarian is trained to properly diagnose a tumor.

Skin Tumors on Dogs - Diagnosis


Treatment will depend on each individual case and will be carried out according to the particular type of tumor and conditions of the sick dog.

  • Benign tumors usually do not need to be treated because they do not cause any major problems. We only proceed to remove it with surgery if there risks or it is causing the dog discomfort.
  • Malignant tumors are usually removed by surgery, but radiation therapy, cryotherapy and chemotherapy may be used in some cases as alternatives to surgery and as complementary treatments in others.

The prognosis is variable but most skin tumors in dogs can be cured if treated early. Logically malignant tumors in advanced stages have a poorer outcome, but when caught early can be treated effectively.


There is no way to prevent skin tumors in dogs. However, it is advisable not to expose dogs with mostly white fur and hairless dogs to sunlight for a long time, especially around noon.

Good nutrition and proper exercise will certainly help to give them a healthier body, a very important factor but not one that will definitely prevent it. Going to the vet regularly will help us detect the appearance of a tumor as soon as possible. Thanks to early detection we can get a better diagnosis and better treatment. Do not forget it!

Skin Tumors on Dogs - Prevention

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Skin Tumors on Dogs, we recommend you visit our Other health problems category.

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What did you think of this article?
evan dallow
I would really like to be able to save my dog hes not even a year old and i belvie he has this
Any idea what this is. It’s cold but keeps growing it’s on my staffy s neck under her jaw
Administrador AnimalWised
Hi Gemma,

It could be a number of things, but only a veterinarian will be able to diagnose effectively.
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Skin Tumors on Dogs