30 Pictures of Dog Tumors and Growths [With Veterinarian Info]

This article was updated on October 5th, 2026

Featured below is our collection of pictures featuring common tumors, cysts, and growths in dogs. This collection has been compiled by our veterinarians with the hope that it will help pet owners and their veterinarians recognize health issues quickly and take prompt action to help their pets.

Pictures of common tumors, cysts or growths in dogs

1. Lipomas

Lipomas are fatty tumors and are usually benign. True lipomas are non-cancerous and painless. They are typically soft and moveable. View more Lipoma pictures.

2. Sebaceous Cysts

Sebaceous cysts are usually benign and harmless, so while it’s important to have a veterinarian confirm the diagnosis, treatment is often unnecessary unless the cyst becomes irritated, infected, painful, or starts to change. These masses appear as a fluid-filled sac and are non-cancerous. They are usually pink and hairless as shown in the images above. View more pictures of sebaceous cysts.

3. Interdigital Cysts

Interdigital cysts are found on the feet, between the toes. These lesions are areas of deep infection that form in response to chronic inflammation. They occur most commonly in larger, overweight dogs but can occur in any dog, especially if they are a result of a foreign body such as a sticker or grass awn in the paw.

Frustratingly, these types of cysts are not always easily treated and they are notorious within the vet community for resisting treatment and/or coming back. The best treatment will address the cause of the cyst. For example, those with allergic skin disease should avoid their allergens and may need long term medicine to reduce the itching and inflammation. Learn more about interdigital cysts.

4. Mast Cell Tumors

These tumors can often be aggressive and appear white, pink, or covered in fur.  Mast cell tumors are the second most common cancerous tumor seen in dogs; they account for 16-20% of all tumors¹. These tumors have the potential to spread throughout the body incredibly quickly, so it’s particularly important to recognize and diagnose these tumors early. View more mast cell tumor pictures with information from our veterinarians.

5. Mammary Gland Tumors

Mammary tumors can be cancerous or benign and are often next to or within the nipple. The mass may extend between multiple mammary glands and are typically firm. Mammary masses may have ulcerated skin overlaying them or be abscessed/bleeding. View more pictures of mammary gland tumors with veterinarian information.

6. Melanomas

Melanomas may be cancerous or benign but are often very aggressive. These tumors are typically black, but not always and can be raised or flat. Above is a picture of a melanoma tumor in a dog’s mouth (black growth). Learn more about melanomas.

Please note that the pictures are provided as examples only. It usually is not possible to determine the real nature of a dog tumor, cyst, or growth by just looking at it. Learn about biopsies.

7. Warts

These lesions have a cauliflower-like appearance and can be single or a cluster of tiny lumps. The papilloma virus causes them and are benign. Warts often disappear after a few months. View more examples and pictures of warts or find out how to remove dog warts.

8. Skin Tags

Skin tags are small, benign growths on the skin; are typically harmless and non-cancerous.
Learn more about Skin Tags.

9. Squamous Cell Carcinomas

SCC is a malignant tumor that is typically raised and red, as shown on the picture above. These are often found in light-skinned areas or in the mouth and may become ulcerated or bleed. Because SCC can invade nearby tissues and may become more difficult to treat as it grows, any suspicious lesion should be evaluated by a veterinarian promptly. Learn more about SCC or red bumps on dogs.

10. Soft Tissue Sarcoma

These masses are cancerous. There are many different types, depending on the tissue affected (including fibrosarcoma, hemangiosarcoma, liposarcoma). The masses can be soft or firm and are often invasive into surrounding tissue.

11. Anal Gland Tumor (Adenocarcinoma)

There are benign anal sac tumors, but adenocarcinoma are malignant. These appear as a growth on or just next to the dog’s anus.

Important: As veterinarians, we can almost never say what a dog’s growth is without testing it.

For example, we have seen what looks like a lipoma actually come back as a malignant mast cell tumor. Always consult with our local veterinarian to confirm the diagnosis and determine the best treatment plan for your old dog.

Learn more:

• Go to our page on Lumps, Bumps and Growths for more information.
• View our page listing 21 skin conditions in dogs (with pictures).
• Learn more skin lesions or lumps due to cancer.
• Tumors commonly found on dogs’ legs.

Overview graphic:

1. Bostock, D.E. (1986). The prognosis following surgical removal of mastocytomas in dogs. Journal of Small Animal Practice, 27(10), 723-737. [↩]