What clues help vets evaluate lumps on dogs?
- Color: The color of a lump may give some hints about what kind of growth it could be. For example, darker lumps may indicate melanoma.
- Firmness: How a lump feels may also be important. Hard lumps can be more concerning, especially if they don’t move easily.
- Shape: Lumps with smooth edges and a regular shape may be less concerning than those with uneven or irregular edges.
- Size: Larger lumps may be more likely to affect the nearby healthy tissue. But even small lumps can be concerning.
- Changes in appearance: A lump that changes in size or color over time may be more concerning than one that stays the same.
- Growth: A lump that grows quickly may signal an aggressive cause.
- Rawness: The skin over a lump may become raw or develop sores. This can happen if the lump grows quickly or gets irritated. This is called ulceration.
Keep in mind, though, that while the appearance of a lump might offer clues, it isn’t possible to make a reliable diagnosis based on looks alone. Proper evaluation—such as a physical exam and diagnostic testing—is needed to fully understand what it is.
How do veterinarians diagnose the cause of lumps on dogs' skin?
Often, your vet will recommend testing a lump or bump to determine its cause. With information from diagnostic tests, your vet can explain what the finding means and advise you on treatment or monitoring.
Tests your vet may recommend include:
- Fine needle aspirate (FNA) and cytology: This is a quick, simple way for your vet to learn more about a lump without surgery. It involves collecting cells from a lump with a needle. FNA takes only a few seconds and is usually well-tolerated by dogs. Your vet may look at the cells to see what type they are right in the practice or they may send the sample to a specialist for review.
- Biopsy and histopathology: Your vet may recommend that a larger piece of the mass is collected for evaluation. A biopsy will likely require giving your dog a calming agent such as a sedative or anesthesia. The sample from the mass is then sent to a laboratory, where a specialist examines it under a microscope.
Why get a lump tested?
The tests your vet does can let you know what type of mass your dog has. In many cases, lumps and bumps turn out to be benign (noncancerous) growths. If testing shows that your dog's mass is cancerous, your vet will discuss with you the next steps.
If your vet determines that the dog’s lump is noncancerous, you may not need to have it removed. However, they may recommend surgery to remove a cancerous (malignant) lump or a benign lump that gets infected, frequently bleeds, or becomes large enough to hinder movement. Your vet may also recommend other treatments, such as medication or radiation therapy.
Choosing the right treatment for a lump starts with understanding what caused it.
What to do if you find a lump or bump on your dog
If you find any new masses on your dog, schedule a visit with your vet. In most cases, getting a lump checked is not urgent, and you can schedule an appointment within the next week or so. However, you should schedule a visit sooner if you notice:
- Skin sores, bleeding, or oozing from a lump
- A lump that increases in size over days or weeks
- Your dog seems painful (moving away or trying to bite) when you touch the lump
- A lump in a sensitive area, like in the mouth, around the eyes, or under the tail
- Tiredness, loss of appetite, weight changes, limping, or other signs of illness
Although some masses on dogs are harmless, others are more serious. It’s best to schedule an appointment with your vet so you understand the possible causes and make the best plan for your pet.
Final thoughts: Ask your vet what testing is recommended
It's normal to be concerned about finding a new mass on your dog. If you notice a new lump or bump, ask your vet what testing they recommend. Although some masses may be nothing to worry about, it's best to know if your dog's mass needs treatment. That way, you can make an informed decision for your dog’s care.
Frequently asked questions
Frequently asked questions about this topic
It is best to have all new lumps checked by your vet. Although some lumps are not concerning, your vet can let you know what kind of testing is needed.
You can't tell if a lump is cancerous by feeling it. Certain characteristics give your vet clues, but the only way to know for sure is to have your vet run diagnostic tests. This testing involves collecting and evaluating samples of cells from the lump.
No, many masses dogs get are not cancerous. Dogs can have noncancerous growths, skin infections, and other conditions that cause a lump to form. Your vet can run tests to let you know whether your dog's mass is concerning and needs treatment.
