Just like humans, dogs and cats often develop lumps and bumps throughout their lives. Luckily, less than half of them turn out to be malignant or cancerous. Still, it is important to check your pet’s skin and body regularly and monitor any growths closely.

Since we have already discussed cancerous tumors and skin tags, this post will focus on the benign lumps and bumps you might find on dogs and cats. We’ll cover the many different types, why they develop, and when you should see your vet.

Non-Cancerous Lumps and Bumps on Dogs and Cats

Although the growths on this list are typically benign, some can still be harmful to your dog’s health. Infectious growths need to be treated with antibiotics, while others may indicate an underlying condition. In rare cases, some lumps can even turn cancerous if left unattended. For these reasons, it is important to seek veterinary attention any time you identify a new growth on your dog or cat.

Lipomas

Lipomas are often mistaken for cancerous tumors because they often appear suddenly and can grow quite large. Fortunately, these soft, round growths are entirely composed of fat cells and are completely harmless to your pet’s health.

Often seen in older and/or overweight dogs and cats, lipomas are typically only removed for cosmetic reasons or if they are causing a functional issue for the pet. For example, a large lipoma on the chest or abdomen may obstruct your pet’s mobility or make it difficult for them to lie down comfortably.

Histiocytomas (Button Tumors)

Histiocytomas look and sound more frightening than they actually are. These small, red bumps often look like little buttons on your pet’s skin; hence their nickname, button tumors.

While rare in cats, histiocytomas appear frequently in young dogs. Most affected pups are between eight weeks and three years old, but these growths are typical in dogs up to age six. Button tumors are most common on the legs but can develop on the trunk of the body as well. They are caused by the overproduction of certain immune cells called Langerhans cells that help protect the body from cancer.

Histiocytomas tend to disappear harmlessly on their own, but since they can resemble other types of cancerous growths, it is important to have them checked by your veterinarian.

Sebaceous Cysts

These greasy little bumps are caused by blocked oil glands and may be mistaken for warts or pimples. While harmless to your dog or cat, sebaceous cysts can be messy, releasing a whitish fluid known as sebum. Since they are small and often seen in long-haired breeds, these cysts can be painfully nicked during grooming. They may also bleed or become infected if ruptured.

Even though they are not especially threatening to your pet’s health, your vet may recommend having sebaceous cysts surgically removed if they become a nuisance.

Warts

Warts on dogs and cats are similar to sebaceous cysts in size and appearance but do not contain fluid. They tend to be irregularly shaped and may look like a tiny head of cauliflower. Warts are most common in older dogs and very rare in cats.

Warts are caused by the species-specific form of the Papillomavirus, meaning they are contagious from pet to pet, but not from pet to human. Like lipomas and cysts, warts are mainly a cosmetic issue and usually disappear on their own without causing your dog or cat too much trouble. Some daycare or boarding facilities require surgical removal of papillomas because they are potentially contagious to other dogs through licking or direct contact.

Skin Tags

Skin tags may be the least concerning of all the lumps and bumps on dogs and cats. They appear as raised, fibrous flaps of skin and tend to be quite small. Caused by overactive cells called fibroblasts, skin tags can develop in pets of any age, but rarely cause problems.

Abscesses

When a dog or cat gets a puncture wound, bug bite, animal bite, or infection of some kind, the surrounding tissue can become quite swollen. Your pet’s immune system may react by forming a pocket of pus beneath the skin, resulting in a scary-looking lump that seems to appear out of nowhere.

Abscesses can be quite painful and may rupture if not treated early. Dogs and cats with abscesses are also likely to suffer from fever and flu-like symptoms unless promptly cared for by a vet and treated with antibiotics.

Acne

Believe it or not, cats and dogs get acne, too! It occurs when a hair follicle becomes plugged with dirt and oil and is most common on the chin, lips, and muzzle. Feline and canine acne may simply appear as tiny blackheads, but infected bumps can be much bigger and cause itching, redness, and irritation.

Schedule an appointment with your vet. He or she can prescribe medicated washes or wipes to help heal the lumps and bumps. Occasionally, local anesthetic and drainage are required for cystic acne to heal.

Ticks

Ticks come in many shapes, sizes, and colors, meaning they can often be mistaken for growths on dogs and cats. Depending on where you live and your lifestyle, ticks can even be a problem for indoor pets as they may hitch a ride on you, your kids, or other pets.

If you find a tick on your dog or cat and are not comfortable removing it yourself, your veterinary staff can help. While some tick bites are little more than a nuisance, others can transmit disease or even be life-threatening.

Bug Bites

Unlike ticks, most bugs don’t stick around after biting or stinging your pet, but they can still cause lumps and bumps. Fleas, mosquitoes, bees, hornets, wasps, spiders, and certain ants can all cause irritating reactions on your pet’s skin.

Most dogs and cats have little more than mild irritation from bug bites, but those that are allergic or particularly sensitive may develop rashes, hives, or large areas of swelling at the site. If your dog or cat develops facial swelling, vomits, has difficulty breathing, or seems particularly uncomfortable after a bite or sting, see your vet immediately. Antihistamines or steroids may be necessary to counteract the reaction.

Hives

Speaking of histamine reactions, dogs and cats may develop itchy, bumpy hives if their skin becomes irritated. While a mild case of hives will likely resolve on its own, a particularly severe case or hives accompanied by other allergic reaction symptoms may require veterinary care.

Vaccine Reactions

It is fairly common for dogs and cats to develop lumps and bumps after receiving vaccinations. These are usually mild reactions that tend to resolve on their own within a week or two. Vaccine-related bumps are usually small and firm and may be itchy or tender to the touch.

In rare cases, infections can occur at the injection site, so be sure to monitor your pet for signs of swelling, redness, pain, or discharge any time they receive a booster. You should also contact your veterinarian if the swelling lasts longer than three weeks, gets larger, or becomes more painful.

While it is extremely rare, some pets develop malignant tumors at the site of an injection. These may show up long after the vaccination is given, highlighting the importance of frequent body checks for lumps and bumps on your pet.

When To See Your Vet

While it is best to err on the side of caution and have your veterinarian examine any new lumps or bumps, some growths are more worrisome than others. Check your pet frequently for firm, irregularly shaped, irritated, or oozing lumps. It is also important to monitor the size, texture, and color of existing growths and contact your vet if you notice any changes.

Diagnosis And Treatment

Your vet will do a full exam on your pet and determine if a fine-needle aspirate or biopsy is warranted. He or she will want to know:

If the lump appeared suddenly or grew quickly
Whether it has changed shape, color, or size
If there are changes in your dog’s behavior, appetite or energy level
If the bump is painful, itchy, or irritating to your pet

If necessary, a fine needle aspirate can be performed on the spot. The procedure involves using a thin needle to collect cells from the growth. These cells are then examined under a microscope to determine if there is a need for further testing.

Biopsies are more invasive than fine-needle aspirates and may require sedation or even full anesthesia depending on the size and location of the tumor. Sometimes your vet will perform a punch biopsy, which involves using a special tool to extract a sample from the center of a lump or bump. In other cases, the doctor may choose to remove the entire growth for analysis.

Treating lumps and bumps in pets depends wholly on the type of growth you are dealing with. Therapies may include surgical removal, antibiotics, steroids, radiation, or chemotherapy.

Remember, most lumps turn out to be harmless. But as with any illness, early detection is the key to successful treatment and a good long term prognosis.

Lumps And Bumps On Dogs And Cats