Pictures of Dog Tumors and Cysts [by a Veterinarian]

This article was updated on September 1st, 2023

You will find below a list of pictures of tumors and cysts that are often observed in dogs. 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.

Important: As veterinarians, we can 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.

Common cysts, tumors, or growths in dogs (with pictures)

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.

1. Lipomas

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

2. Sebaceous Cysts

These massses appear as a fluid-filled sac and are non-cancerous. They are usually pink and hairless as shown in the two images below. View more pictures of sebaceous cysts, and more pictures of cysts in dogs.

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. View more pictures of bumps on paws or cysts in dogs.

4. Mast Cell Tumors

These tumors can often be aggressive and appear white, pink, or covered in fur.  View more mast cell tumor pictures.

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. Melanoma

These 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).

7. Squamous Cell Carcinoma

SCC is a malignant tumor that is typically raised and red. These are often found in light-skinned areas or in the mouth and may become ulcerated or bleed.  

8. 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.

9. 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.

10. 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.

11. Skin Tags

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

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.

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