Common Types of Cat and Dog Skin Cancer Malignant Tumors on a Pet

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Pets are at risk for a variety of skin cancers that must be caught and treated early.

Even the most conscientious pet parents who carefully plan nutritious diets  for their dog or cat and diligently visit the vet for annual checkups may not realize they need to take steps to protect their petโ€™s skin.

Skin cancer is the most common type of canine cancer and the second most common feline cancer. Not every lump or growth on a pet is a malignant tumor, but because certain types of skin cancer can be very aggressive and fatal, you should check your pet regularly for new bumps or changes in their skin. If you find anything unusual, take your pet to the veterinarian as soon as possible.
Hereโ€™s what you need to know about some common skin tumors.

Mast Cell Cancer

The skin tumors seen most frequently in dogs are mast cell tumors (MCTs). Among cats, MCTs are the second leading cause of skin cancer. Treatment and prognosis for your pet will depend on the grade of tumor, which can range from benign to highly malignant. Unlike the most prevalent forms of human skin cancer, sun exposure doesnโ€™t seem to play an important role in mast cell cancer in pets since these tumors can develop on body parts heavily protected by fur or that donโ€™t receive much sun.

In dogs, some breeds seem genetically predisposed to MCTs. Boxers, Pugs, Rhodesian Ridgebacks, and Boston Terriers are more likely than other breeds to develop mast cell tumors.

Cats can get the same type of MCTs as dogs but may also develop a rare form of mast cell cancer called histiocytic sarcoma. Siamese cats appear to be most at risk for both forms of feline MCTs.

What to look for: Skin MCTs often appear as single raised, hairless lumps. Theyโ€™re usually white but may be pink. Canine MCTs often appear on the belly, back, sides, and limbs. Cats with MCTs usually have growths on their neck or head, including the ears.

Basal Cell Tumor

Basal cell tumors are often benign Even if your dog or cat develops the cancerous form, basal cell carcinoma, the tumor can often be successfully removed without further problems. Cancerous basal cell tumors are the most common skin cancer in cats. Middle-aged cats are most susceptible to these tumors along with Persians and other long-haired breeds. Many breeds of dogs are predisposed to basal cell tumors, including Wirehaired Pointing Griffons and Kerry Blue and Wheaten Terriers.

What to look for:  Basal tumors grow from deep within the skinโ€™s layers. They may occur as a series of small nodular growths side by side on the back and chest of cats. On dogs, these tumors are more likely to appear as single hairless lumps on the head, neck, or shoulders.

Squamous Cell Carcinoma

Sun exposure plays a significant part in the development of squamous cell carcinoma, but other factors such as burn injuries or even viruses can also increase your petโ€™s risk. While other skin cancers are more common in dogs and cats, squamous cell carcinoma can be a more aggressive and deadly cancer if not treated early.

There are different types of squamous cell carcinomas, and different breeds of dogs are more susceptible to each type. Bloodhounds, Basset Hounds, and Standard Poodles are at greatest risk for one type, while white-skinned, shorthaired breeds such as Dalmatians, Bull Terriers, and Beagles are prone to another type. Older dogs are at the greatest risk. Cats with white skin and hair are more likely to develop squamous cell carcinoma because they are more vulnerable to UV radiation.

What to look for: Squamous cell carcinoma may appear as a white or grayish ulcer, cauliflower-shaped lump, or a red bumpy area. These growths may include sores that donโ€™t heal. You may notice hair loss in the area (due to your pet constantly licking it). Itโ€™s common for these ulcers to appear on your petโ€™s belly since dogs and cats often sun themselves on their back. Pets are also at risk for oral squamous cell carcinomas, so you should check your petโ€™s mouth for ulcers as well.

Caring for Pets With Cancer

Several other skin tumors can affect dogs and cats in very different ways, including fibrosarcoma  melanoma, histiocytosis, and lipoma. Treatment for all types of skin cancer usually includes removal of the cancerous growth. Lymph nodes may also need to be removed, and radiation therapy or chemotherapy may be needed to treat inoperable tumors or to ensure that all the cancerous cells are eradicated. Paying attention to the special nutritional needs of pets with cancer is also an important part of helping your dog or cat heal.

The most important thing is to detect cancer early by regularly checking all areas and folds of skin for possible signs of skin cancer.

How to Tell Skin Allergies From Bug Bites?

Itching is one of the most common reasons pet owners take their dogs to the veterinarian. It goes without saying that, just like humans, there are a number of reasons behind why canines lick, chew and scratch themselves.

Why does your dog scratch himself?

Inflammation is also referred to as dermatitis. This condition causes intense itching in dogs. Parasitic and allergic dermatitis are the to most common types of dermatitis. The allergic variant is caused by food allergies, seasonal allergies and non-seasonal allergies. Parasitic dermatitis is caused due to insect bites and stings. Both these conditions have similarities in their clinical signs.

How can you tell the difference between the two?

If your dog is suffering from an acute case of allergic dermatitis, then he may have allergies due to one of the three aforementioned causes. Seasonal allergies are prevalent during summer, spring, and fall. If you live in a region that has predominantly warm/humid weather, then the allergy can persist all year long. Blooming flowers, plants, weeds, grasses and trees are the most common culprits behind seasonal allergies. Non-seasonal allergies can be caused due to molds, dust, environmental materials, chemicals and other factors. Some dogs are allergic to certain protein sources (beef, chicken, dairy) or grains (corn, wheat, rice).If your dog is suffering from allergic dermatitis, then you will see signs of the condition all over his body, but most commonly on the ears, feet, armpits, legs, groin, muzzle, and around the anus. Redness, hair loss, oozing, crusting, hyperpigmentation and skin thickening can occur at the itchy locations.Ticks, fleas and other stinging insects can cause inflammation and discomfort to varying degrees. Some dogs are sensitive to insect bites and some of them are even allergic to the saliva. Your dog will lick, chew or scratch himself on the affected site. The itching pattern will vary depending on where your dog has been stung or bitten, as well as on how sensitive he is to the saliva or venom of the insect.Fleas tend to congregate around the neck, head, tail base, inguinal area and the perineum. The most common sign of a flea infestation is the appearance of black pepper like deposits on the infested site. If your dog has flea dirt, then use a moist cloth and gently wipe the area. If you see an orange or pink tinged reside, then it is a sure fire sign of a flea infestation. Mites, on the other hand, are microscopic insects that dig deep into the skin layers to feed and survive. As they chew their way through your dog's skin, they cause inflammation and secondary infections (yeast, bacteria and so on). Redness, swelling, crusting, oozing, hair loss are the most common signs of mange in dogs.

More on Cancer

Cancer in Dogs and Cats
Liver Cancer in Dogs and Cats
Hemangiosarcoma in Dogs and Cats


โ€œTumors of the Skin and Soft Tissues,โ€ The Merck Veterinary Manual. July 2011 (accessed online November 22, 2013)

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

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