The vet’s office: Benign or serious
Examining lumps and skin growths in animals
By Dr. Elizabeth Knabe, DVM
Wildwood Animal Hospital and Clinic LLC
Skin growths and lumps underneath the skin are very common in dogs. They are often discovered during a pet’s routine health exam. Cats can also have them, though they tend to have fewer than dogs do.
The veterinarian will ask owners if they have noticed any new lumps, so it is important to check your pet prior to an exam. It is helpful if owners have an idea of how long a lump has been present and if it is increasing in size or bothering the pet. No growth can be diagnosed by a history alone, but the information from clients is helpful.
Some of the more common lumps we see in dogs involve fat cells beneath the skin. They form fatty tumors that do not spread to other organs but can enlarge locally. The diagnosis is made by doing a fine needle aspiration (FNA). A small needle is inserted into the lump, and a small amount of the contents is collected and examined under the microscope. Most fatty tumors are just monitored, but some are removed surgically if they enlarge and bother the pet.
Dogs also tend to have sebaceous cysts in the skin, which are lumps from oil-producing glands. The glands have become blocked, allowing the oily and thick contents to build up in a pocket beneath the skin. These sometimes rupture to the surface and cause irritation. If that happens, they can be surgically removed.
Middle-aged-to-older dogs commonly get firm, bumpy skin growths that are benign and resemble human warts. They arise from skin glands and can show up almost anywhere on the body and head. They sometimes bleed and itch. Although they do not spread, they may need to be removed. Cats get benign skin tumors also, but the frequency of growths being potentially malignant is higher than for dogs.
A group of growths and lumps that is more serious is what we call skin cancer. Cats get squamous cell skin cancer more on areas that lack pigment or fur such as the ears and forehead. Dogs get mast cell tumors of the skin that can fluctuate in size as cells release chemicals, creating swelling and redness. There are many other types of skin cancer also. Some look like sores that do not heal, and some may not bother the pet at all.
It is good to bring up any new lumps or skin growths to your veterinarian. It may be a harmless skin growth, or it may be something significant. A vet may want to do an FNA or even a surgical biopsy to be sure. In many cases surgery is curative for skin cancers that are caught early.
Wildwood Animal Hospital and Clinic LLC is located at 210 Airpark Road in Marshfield and online at wildwoodanimalhospital.net.