Pets Get Skin Cancer, Too
Monday, June 29, 2015
It might not be a topic that occurs to pet owners, but skin cancer is as much of a concern for our four-legged comrades as it is for us. Not only can they develop skin cancer, but they can get various types that are only common to their species or breed. It is important when bringing a pet into your home that you know the risks about leaving your cat or dog outside all day - especially during the hot summer months.

Skin Cancer That Is Common for Pets 

The most common forms of skin cancer that are found in humans - melanoma, squamous cell carcinoma, and basal cell carcinomas - also occur in pets. However, pets are also susceptible to skin cancers that humans are not prone to getting.
Approximately, 20-40 percent of skin tumors are malignant in dogs, and 50-65 percent are malignant in cats. It is important to note, however, that skin cancer is much rarer in cats than in dogs.
Basal cell carcinoma, which occurs most frequently in humans, is the most common type of skin cancer in cats - primarily Siamese and domestic longhairs. It occurs as small nodular growths beneath the skin, often appearing next to each other to form solid sheets of bumps. Usually they will appear on the chest and upper back, but tend to show up on the heads of older cats as one single growth. 
Normally, basal cell carcinoma is benign. However, pet owners of longhairs should be the most alert about the presence of these nodules, as they appear malignant more regularly in these type of cats. 

Most common skin cancers in cats include:

  • Basal Cell Tumor
  • Mast Cell Tumor
  • Fibrosarcoma
  • Squamous Cell Carcinoma
  • Sebaceous Hyperlasia/Adenoma
The most common form of skin cancer in dogs - particularly Labrador and Golden Retrievers, Boxers, Boston Terriers, Beagles, Schnauzers, and Pugs - is mast cell tumors. This type of skin cancer accounts for 20 percent of all skin tumors in dogs.
Mast cells are naturally occurring cells in the skin and other tissues, such as the intestines and respiratory tract and are an essential part of the immune system. A mast cell tumor occurs when there is a release of many mast cells in a specific area. Since mast cells contain histamine, heparin, and enzymes, they can create problems when removed such as affecting heart rate, blood pressure, and other body functions. The site where the tumor was removed can also have a difficult time healing.
Although mast cell tumors can appear on many areas of your dog, they most commonly will arise on the trunk, limbs, and perineal (genital) areas. Sometimes they can be confused for allergies because when they arise they appear as raised, hairless, pinkish-yellow masses and are known to swell up only to disappear again.

The most common skin cancers in dogs include:

  • Mast Cell Tumor
  • Hepatoid (Perianal Sebaceious) Adenoma/Carcinoma
  • Lipoma
  • Sebaceous Hyperplasia/Adenoma
  • Histocytoma 

The Dangers of Sunbathing

As a human you probably hear this regularly, but you probably did not realize the same goes for your pets. This is especially true for pet owners of white or thinly furred pets. White cats and dogs or those with thin hair have less resistance to the sun's rays. If your pet also has a tendency to lay on its back while outside in the sun, they are also susceptible to developing skin cancer on areas of their stomach.
While it is rare for dogs to develop squamous cell carcinoma, light-haired dogs are the most susceptible. So ask your veterinarian about safe sun-screen for your dog to wear while it is outside.

Dog Breeds Most Susceptible to Skin Cancer

Any type of dog can develop skin cancer just like any person can; however, some are more genetically predisposed to develop certain kinds of skin cancers than others.
Benign Melanocytomas - appear most regularly in dogs between 5 and 11 years old.
  • Vizslas
  • Miniature Schnauzers
  • Doberman Pinschers
  • Airedale Terriers
  • Bay Retrievers
Malignant Melanomas - appear more frequently in black dogs. 
Squamous Cell Carcinomas - appear most frequently in dogs between 6 and 10 years old and in dogs with short coats.
  • Keeshonds
  • Standard Schnauzers
  • Basset Hounds
  • Collies
  • Dalmatians
  • Bull Terriers
  • Beagles 
Mast Cell Tumors
  • Boxers (most commonly found)
  • Boston Terriers
  • Labrador Retrievers
  • Beagles
  • Schnauzers 
While it can seem scary, the good news for pet owners is that most skin cancers can be easily treated by their vet if caught in time. So if you notice any abnormal bumps or nodules on your pet, don't hesitate to ask your vet about it.  
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Pets-ercise provides dog walking and pet sitting services to the Norfolk, VA area. Tara, a certified professional pet sitter, is a life long pet lover and has personal experience and compassion for both senior citizen and special needs pets. Contact her today if you plan to be out of town or have a hectic work schedule that requires your pets to be alone for long periods of time.