My Dog Has Bumps Under Her Fur? 7 Causes and What to Do

It can be alarming when you’re petting your dog and feel strange bumps underneath their fur, whether they’re just small bumps or larger lumps. You may just think something bit them, or you may worry that it’s a cancerous tumor if it’s larger.

A number of things can cause bumps or lumps under a dog’s fur. The cause depends on the size, shape, and severity of the bumps you’re feeling.

It could be something minor like an allergic reaction, or it could be a serious skin condition that requires veterinary care. It could even be a sign of cancer, which requires early care for the best chance of survival.

It’s important to know the different kinds of bumps and lumps you can feel under your pup’s skin and how to address them.

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Bumps and lumps can appear under a dog’s fur for any number of reasons, ranging from non-serious to possibly life-threatening.



A minor bump or zit could be an allergic reaction. Dogs suffer from allergies just like we do. And just like us, there are many types of allergies that can cause bumps.

They could be having an allergic reaction to an insect bite, or a skin allergy to grass or another plant. Even a food allergy can trigger skin problems.

If your pup’s bumps are showing up after interacting with grass or plants, they may be suffering from skin allergies. They may also be itchy and scratch a lot around the areas where the bumps are.

They may have also been bitten by one of the many insects roaming outside, especially during the summer months. If this is a common issue, you may want to invest in a dog-safe bug repellent.

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If your companion’s lumps are appealing shortly after a food change, they may be having an allergic reaction to the food. They can also develop an allergy where there wasn’t one before. You may notice other signs like an upset stomach and vomiting.

Make sure to see a vet for advice if your pup’s allergies are getting out of hand. They may need an allergy shot or a food change.


Warts are a fairly common type of cauliflower-like bump that’s especially common among puppies whose immune systems are still developing. They may go away on their own, but it’s best to call a vet for advice, especially if you’re new to this.

Be careful if you think your puppy has warts. It can be a highly contagious disease that can easily pass between dogs (though thankfully not humans).

Keep your puppy isolated from any other dogs. If you do decide to call the vet, make sure you tell them you think it may be warts so they can take appropriate measures.

Thankfully, warts can often go away on their own and aren’t too serious. They often appear on the feet, face, lower legs, or around the eyelids. They may appear in clusters or by themselves. That said, the vet should still be consulted if they’re causing your pup any irritation.

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Warts can be a common problem among puppies whose immune systems haven’t fully developed yet. While they aren’t usually a huge cause for concern, it can be a good idea to call a vet to be safe.


Lipomas are fat-filled lumps that may naturally appear under your companion’s fur as they age. They’re mostly harmless, soft lumps that your dog doesn’t even feel. They can look and feel gross and scary, but as long as your pup isn’t in pain or hindered by it, you usually don’t need to worry.

These benign lumps appear more often in older dogs and larger breeds. They’re also more common among obese pups. If you’re worried that obesity is causing your pup to get these lumps, you may want to work on a diet to get some weight off of them.

If these lumps seem to cause pain for your pup when you touch them or are getting in the way of movement, it may be best to call your vet. They can remove it if necessary.

Sebaceous Cysts

Sebaceous cysts look like small, pimple-like warts. They can appear on older dogs, usually on their backs. They are hard, swelled bumps with a cream-like matter inside of them. These cysts can eventually burst like pimples, releasing a white substance. The swelling can become red and sore.

They are caused by a blocked sebaceous gland causing problems. These cysts may be more common among breeds with fine hair like Poodles.

While they sound gross and horrible, they usually disappear on their own. That said, they can also remain for a long time and cause infection.

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Sebaceous cysts are hard, swelled bumps with a white substance in them. They can burst if given enough time.

It’s important to look for any signs that they’re causing your pup pain. Watch for any signs of infection or illness and call your vet if you think it’s a problem. They can remove it if necessary.

Skin Tags

Skin tags are mostly harmless bumps that look like raised flaps of skin or small lumps. Some skin tags may have hair growing on them, though not always.

These bumps are caused by overactive cells causing mayhem and are mostly harmless. They can occur in any dog of any age or breed, though older pups may get them more.

While skin tags are often harmless and should go away on their own, you can have your vet look at them to make sure if you’re worried. They may especially want to look if the skin folds change color or shape.


Abscesses are swollen tissue usually caused by infections of a wound. They may appear around wounds and sores like bug bites, animal bites, or other wounds. They can burst if left alone and cause pain for your pup.

If you notice abscesses on your pup, you should go ahead and call your vet. There is probably an infection or wound associated with it that’s irritated and also needs attention. Your pup may need antibiotics to get better.


Cancerous tumors are never a pleasant thought, but it’s important to rule out if you notice any hard lumps under your pup’s fur. Cancerous tumors need to be diagnosed and removed ASAP, so it’s important to stay on top of them.

There are many types of tumors that can appear on your pup’s skin, namely mast cell tumors. Mast cell tumors are usually hard to the touch and may have an unusual shape. They’re most common in older dogs.

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Hard bumps that are unusually shaped may be a sign of a tumor that needs to be removed. If you think there’s even a possibility that your pup has a tumor, you need to call a vet ASAP.

If you suspect that there’s even a chance that the lump on your pup’s skin is a tumor, call the vet right away and bring them in. They need to be diagnosed quickly so the tumor can be identified and removed.

Depending on how far the cancer spread, your dog may require additional treatment.

When to Call the Vet

While many bumps and lumps may go away on their own, it’s always important to know when to give up trying to solve it on your own and call the vet.

While many lumps like lipomas are usually harmless, you should always pay attention to how your companion is feeling. If the lump seems to be causing them pain or making it harder to move in any way, you should call the vet.

If your pup has an abscess surrounding a wound, it’s best to get them to the vet before it causes more harm. It’s especially crucial if you think your pup has been wounded by something dangerous that would cause a serious wound.

Always call the vet if you see a hard, weirdly shaped lump under your dog’s skin, as it may be a cancerous tumor. Even if you’re wrong, it’s better to be safe than sorry.

If your dog’s lumps are accompanied by vomiting, diarrhea, or lethargy that lasts longer than 24-48 hours, you should call the vet. You should also contact the vet if you see any concerning signs of infection or inflammation around the bumps.

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While many bumps are benign and will go away on their own, you should call the vet if they seem to be causing your pup pain or irritation or if the bumps are infected or inflamed.

Taking Care of Your Dog’s Skin

Bumps and lumps under your dog’s skin can be scary because there are so many potential causes. Even worse, those potential causes can range from minor to major. They could be suffering from allergies, or they could have cancer.

If you notice these skin annoyances, it’s important to immediately take note of what kind of bumps they are. Are they just minor skin irritations? Are they small substance-filled lumps? Or are they hard, weirdly shaped lumps? Always call your vet if you think it’s cancerous, inflamed, or infected.

Most skin bumps can be left alone, but it’s important to keep an eye on your dog’s reactions. If the lumps don’t seem to be bothering them, they could just be from aging, allergies, or weight issues. If you notice they are causing your pup pain, call the vet.

Always keep your emergency vet’s information on hand in case you find something deeply concerning. Never be afraid to at least call and set up an appointment if you’re worried, as it’s always better to be safe than sorry.

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