Dog Tumors: What You Need To Know

Dog Tumors: What You Need to KnowWhen you feel a lump or bump on your dog that you haven’t felt before, fear sets in. Thoughts of your dog having a tumor take over. Growths and masses are a common occurrence on dogs, but this can be very scary and you probably have a lot of questions. This is not the time to panic, however, it is the time to get informed.

What Does A Tumor Look Like On A Dog?

Tumors come in all shapes and sizes. Here is what to look for.

  • Raised area on the skin or under the skin
  • They can be soft or hard to the touch
  • Some are round and others have irregular borders
  • It may be red and it may also bleed
  • They can range in size from pea size to a much larger mass

Dog Cyst Vs Tumor, How To Tell The Difference

The first thing to do is to determine if what you are feeling is a cyst or a tumor. Unlike tumors, cysts are fluid-filled sacs under the skin that are easy to move around. It may have a point of drainage on it and may produce white, yellow or green discharge. It is important to remember that these rules are not set in stone. It is always best to see your veterinarian for a proper diagnosis. Cysts are usually less serious than tumors but, if you determine that you’re dealing with a cyst, you’ll still want to make an appointment with your veterinarian to have it evaluated.

Types Of Dog Tumors

There are several different types of tumors in dogs, but not all of them are cancerous.

Mast Cell Tumors

Mast Cell Tumors are one of the most common malignant tumor in dogs. This type of skin cancer produces tumors that contain the chemical histamine. This chemical causes the tumor to be red and itchy.

These tumors originate in the mast cells and can range from low grade, where treatment is to surgically remove the tumor, to high grade, where the tumors have spread, and treatment goes beyond surgery to also include radiation and chemotherapy.


Lipomas are a very common fatty tumor that feels soft to the touch and can be moved around under the skin. This type of benign tumor is usually not a problem and is only removed if it is bothersome to the dog.


Osteosarcomas can be the likely culprit if you find a dog limping as this is the most common symptom. This malignant bone cancer mostly shows up in the legs. Treatment typically includes amputation followed by chemotherapy. Sometimes amputation can be avoided by bone grafting or metal rod placement once the dog tumor is removed. This can be costly and invasive but may be worth it when considering how your dog will deal with amputation.


Histiocytomas are benign tumors that mostly affect dogs under three years old. These “button tumors” are hairless, red, raised lumps that often resolve on their own.


Hemangiosarcomas are a cancerous tumor on dog spleens. It is a blood vessel cancer that has a risk of rupture, which would cause internal bleeding. They often treat this cancer by removing the spleen and then prescribing a chemotherapy regimen to reduce the risk of the cancer spreading.


Melanoma is as much of a risk to dogs as it is to humans. This malignant tumor appears on the skin as a black or dark brown spot. Sometimes the tumor can be removed, but if the cancer spreads, a combination of surgery, radiation and immunotherapy will likely be needed. Learn more about Melanoma in dogs.


Lymphoma is a cancer of the lymph system and is often first noticed in swollen lymph nodes behind the knees, under the shoulders and in the jaw. These tumors in the lymph nodes are often treated with chemotherapy.


Papillomas are a benign tumor caused by a virus known as papillomavirus. They look like warts and appear around the eyes, on the lips, and inside the mouth. It can take weeks or months for the warts to go away and your dog may be contagious during this time. Treatment is often just trying to make your dog more comfortable, but may also include removal.

Are There Other Signs That It Might Be Cancer?

Several other signs indicate that your dog may be dealing with cancer. It will help to be aware of the physical and emotional signs of cancer.

  • Large growths
  • Growths that are constantly growing and changing
  • Abnormal swelling
  • Sores that won’t heal
  • Loss of appetite
  • Weight Loss
  • Lethargy
  • Strong Odors
  • Bleeding or discharge

Learn more about these cancer signs in this video:

Cutting The Cost Of Cancer Treatment

If you are worried about the cost of treatment, you may be thinking about how to treat dog tumors at home. Though there may be some holistic ways to try and treat noncancerous tumors on dogs, that is not the best choice. You really need to see your veterinarian to determine what kind of tumor your dog is dealing with so they can recommend the best treatment. The best way to defray the high cost of treatment is by having pet insurance. Be sure to check out Healthy Paws pet insurance plans and get a free quote today.

Dixie Mae’s Story

  • Pet Parent: Susan
  • Pet: Dixie Mae (7-year-old American Staffordshire)
  • Diagnosis & Treatment: 23 growths removed, not all benign
  • Claim Cost: $15,880
  • Healthy Paws Pet Insurance Reimbursement: $9,577 (80%/$500 and some pre-existing conditions were not covered)

“A couple of months ago, I noticed a small bump on her backside to the right of her tailbone,” says pet parent Susan. When the growth began to get bigger, they decided to get it checked out. The vet decided to remove the growth, but before that happened, a few more growths became noticeable. “It ended up that three of the four growths were malignant and the other one was a benign growth.”

Sometimes, when you find a growth on your dog, it can be a simple procedure to remove it. However, that is not always the case. You may find that you need to have tests, biopsies and surgeries to deal with the situation.

Pet parent Susan says, “Given Dixie Mae’s history of skin issues, I have come to realize it is better to be proactive than reactive,” Susan inspects Dixie May regularly to stay on top of growths that arise. Over the past two years, she has had 23 growths removed, some malignant and some benign. “Having Healthy Paws Pet Insurance has enabled me to truly be proactive and have Dixie treated by the best veterinarians,” says Susan.

Pet Your Dog Often To Notice Concerns

We all want to make sure we keep our pets happy, healthy and safe. So remember, if you see something or feel something out of the ordinary it is always best to get it checked. Your veterinarian is trained, not only to diagnose and treat tumors but also to guide you through the treatment process and inform you of all your options. Being informed and prepared will help you focus on the most important thing of all, giving your dog all the love they need.

Has your dog had a tumor?