Breeds that are more likely to get this type of skin cancer include Keeshonds, Standard Schnauzers, Basset Hounds, Collies, Dalmatians, Bull Terriers, and Beagles. In general, dogs with short coats (especially those with light skin) are more prone to squamous cell carcinomas.

 

 

Malignant Melanoma
This type of cancer affects pigmented cells in the skin known as melanocytes. While many tumors that develop in these cells are benign, others grow quickly and metastasize to other areas of the body like the liver and/or lungs.  Benign melanomas, known as melanocytomas, are typically found on areas of the dog’s skin that have hair, whereas most malignant melanomas occur on or in the mouth. Trauma and compulsive licking may contribute to the rapid cell growth that causes melanomas, but genetics also seems to play a role.

Squamous Cell Carcinoma

 

These malignant tumors usually appear as raised white lumps on the skin, in the nail beds or the mouth. They’re often caused by sun exposure, but they may also be connected to the papillomavirus in certain dogs.  Although squamous cell cancers do not spread to surrounding lymph nodes, they are aggressive and may require large surgical margins to remove.

 

 

 

These are the most common dog skin cancers. The exact cause of mast cell tumors is unknown, but they have been linked to inflammation, irritants on the skin, and genetic factors. The hormones estrogen and progesterone may also affect tumor growth.  A mast cell is a type of white blood cell that is found in many tissues of the body. Mast cells are allergy cells and play a role in the allergic response. When exposed to allergens (substances that stimulate allergies), mast cells release chemicals and compounds, a process called degranulation. One of these compounds is histamine. Histamine is most commonly known for causing itchiness, sneezing, and runny eyes and nose – the common symptoms of allergies. But when histamine (and the other compounds) are released in excessive amounts (with mass degranulation), they can cause  full-body effects, including anaphylaxis, a serious, life-threatening allergic reaction.