Should I Be Worried About a Lump on My Dog?

For most owners, a new lump on your dog can be a source of panic and worry. Most people associate lumps on dogs with one of the most common causes of lumps in people: cancer. But it's important to keep in mind that many different types of lumps can develop on dogs for all kinds of reasons, including some which are hereditary, and many which pose no serious health risk to your dog.

Even so, lumps shouldn't be ignored. Whether your dog has developed a new lump suddenly, or you have noticed several lumps that have developed across your dog's body, it's always better to be safe than sorry and to have the areas inspected and prescribed the appropriate treatment. Here's an overview of the different types of lumps you might find on your dog, and how to make sure these lumps are appropriately addressed.

Portrait of an old gray-haired dog close up

Common Types of Lumps on Dogs

Many different types of lumps may appear on your dog's body, including some that are fairly rare. But most bumps on dogs fall into one of several broad categories:

  • Lipomas – These are among the most common types of lumps on dogs, and are fortunately a growth that owners don't need to worry about. These lumps are fatty benign tumors that may vary in size and can appear across a dog's body, becoming more frequent as they age. However, unless the lump is affecting the dog's mobility or quality of life, there's no health concern or reason to remove the lump. They are typically soft and easily moveable, but it's best to not diagnose at home as they can sometimes resemble the more dangerous cancers.
  • Cysts – A cyst develops when one of your dog's oil glands becomes blocked. These are similar to a zit on a human, although these cysts can grow much larger. Generally, they aren't anything you need to worry about or seek treatment for, and they should go away on their own. Don't pop a cyst, though—this can increase the risk of your dog acquiring an infection through the open wound.
  • Hematomas – A hematoma is essentially a raised bruise that develops as the result of trauma to your dog's flesh. The hematoma itself may be hard, swollen, and tender to the touch, but it doesn't represent a health concern for your dog. The injury underneath the hematoma, though, may need to be evaluated by a doctor to make sure there are no broken bones or serious health concerns.
  • Abscesses – An abscess is caused by an infection, and it should be treated promptly by a vet. These infections will be hot to the touch and painful for your dog, but they don't pose a significant health risk as long as they are treated before the infection spreads to other parts of your dog's body. For this reason, visit a vet or vet hospital promptly to start treatment as quickly as possible.
  • Cancerous Tumors – A cancerous tumor will usually be harder than a lipoma, and won't be hot or sensitive to the touch. The tumor may also be benign, in which case your dog's health won't be jeopardized by this tumor. However, a biopsy should be done to evaluate the tumor and determine whether treatment is necessary.

When Do Lumps on Dogs Develop?

Lumps may develop on your dog at any age. But an older dog is more likely to develop lumps because of the risk factors they may face for cancer or skin issues. In addition, lipomas and other types of harmless lumps are more often associated with their appearance in aging dogs, although young dogs are liable to develop these growths as well. Other lumps, such as hematomas, warts and cancer cells, are more strongly correlated with other health issues that may develop at any stage in a dog's life.

Pet owners should also keep in mind that, with certain types of lumps like lipomas, the presence of one or two lumps may increase the likelihood of more lumps developing down the road.

What Does a Cancerous Lump Look Like on a Dog?

Some types of cancer lumps on dogs will develop on the surface of your dog's skin, which can help owners identify cancer before it reaches advanced stages. Certain breeds, such as boxers and Boston terriers, are especially prone to tumors that grow externally.

One of the best ways to identify a potentially cancerous lump is to evaluate how that tumor feels when touched. Compared to the soft, fatty characteristics of a lipoma, a cancerous lump will be harder and firm to the touch, appearing as a hard immovable lump on your dog. A lump on a dog's neck or face may also prompt foul-smelling discharge from the mouth, nose or eyes, and this smell can be another indicator that the tumor is cancerous.

Ultimately, it's difficult to know whether a tumor is cancerous just by looking at it. Even your veterinarian will likely need to conduct a biopsy to determine whether the tumor is benign or malignant.

When Should You Visit Your Vet?

Typically, hard, immovable lumps that suddenly appear tend to be more worrisome than soft, moveable or slow-growing lumps, but that's not always the case for every type of cancer or abscess. Because lumps on dogs can be difficult to identify and evaluate at home, owners are encouraged to consult their vet and find out if the lump should be tested and identified.

Lumps are likely to develop at some point in your dog's life. In cases such as cancer lumps or an abscess, early detection and treatment can improve your dog's quality of life, and potentially save them from serious and life-threatening consequences.