Posted by Dr. Pamela Barker
Discovering an unusual growth on your pet’s body can be a scary experience. With so much media attention devoted to the dangers of cancer, the sudden realization that your pet might have a tumor is understandably distressing. Knowing what to look for can help you spot potentially dangerous situations and may even save your pet’s life.
First, a little reassurance: skin growths and lumps that develop below the skin surface are a fairly common occurrence, especially in middle-aged and senior dogs. Many are completely harmless — a cosmetic issue, at worst.
As pets age, changes occur in the skin that can cause an overgrowth of skin cells — commonly referred to as skin tags. Some dogs, especially smaller breeds such as poodles and spaniels, are also prone to plugged-up oil glands or hair follicles. These cyst-like growths may be unsightly, but they’re not problematic unless they break open and become irritated or bleed.
Larger breeds, particularly retrievers, are prone to fatty tumors beneath the skin or within muscle tissue. These fat deposits, called lipomas, are soft and can rapidly grow quite large. Lipomas can cause discomfort if they interfere with the animal’s movement, or if their size causes the overlying skin to stretch. In very rare instances, fatty tumors can prove malignant, behaving like more aggressive types of cancerous growths.
So when should you become concerned?
First, beware of growths that look like wounds but don’t heal. This is particularly true for cats. Tumors of the ears, nose and face may begin as reddened, scabbed areas rather than lumps.
Just like people, pets can suffer from melanomas: malignant growths of skin pigment cells. (White-faced animals, like fair-skinned people, are particularly prone to these skin tumors.) Melanomas tend to dark or black in colour, but may also be pale or pink. When these tumors occur in or around the mouth or feet, they can be extremely aggressive, and may spread to the lungs or bone. If you find a mass fitting this description, an immediate trip to the vet is called for.
A mast cell tumor is another common type of cancer — one that can be particularly deceiving. Mast cell tumors generally occur on or under the skin. They tend to be small and grow slowly, sometimes over a period of months or even longer. They look unimpressive, so many owners simply don’t realize how dangerous they can be. These tumors release histamine — the same chemical that the body produces in response to an insect bite or sting — so you may notice your pet scratching or chewing at the area. The lump may also be red, and may vary in size — becoming smaller over time, then growing larger. Again, schedule a visit with your veterinarian as soon as possible. Left untreated, these tumors can become extremely aggressive, potentially spreading to internal organs.
Female dogs and cats that have not been spayed, or that have been spayed later in life, stand a higher risk of developing breast cancer. These tumors occur on the belly, often starting out as firm growths under the skin that feel like tiny pebbles. They can multiply rapidly, and may spread to the lungs or lymph nodes.
Cats are less likely than dogs to develop abnormal growths — but those tumors that do occur are more likely to be cancerous. Some of the most aggressive types of tumors are deceptively innocent in appearance, so a good rule of thumb is to have any growth on your cat checked out as soon as possible. Don’t wait to see if the mass grows. Early diagnosis and treatment can be critical to preventing the advancement of the disease.
If you’ve found an unusual growth, make a point of marking the location prior to the examination. You’d be surprised how often a readily noticeable lump will seem to move or disappear once you’re in the vet’s office — especially if you happen to have a large or long-haired animal. Clip the hair short in the vicinity of the lump, or use a permanent marker on a light-coloured pet. Lipstick also works well and is easy to remove.
For a definitive diagnosis of any abnormal growth, you must arrange a veterinary exam. But your sharp eyes and vigilance are also key to ensuring early diagnosis and successful treatment.
Dr. Pamela Barker is a professional veterinarian with more than 15 years of experience, currently practicing in 100 Mile House, B.C. Her special areas of interest include animal behaviour and training, nutrition and condition for canine athletes, and public education about animal health and care. If you’d like to suggest a topic for one of her future blog posts, please feel free to leave a comment below.