Hemangioma in Dogs

Skin lesions may turn out to be a harmless hemangioma, or a deadly hemangiosarcoma. A trip to the vet and a biopsy are needed to determine the best course of further action.


It usually happens when you’re grooming or bathing your dog: You notice a strange little lump you haven’t seen before. The first thing to pop in your mind is the C-word. It can’t be cancer, can it? Chances are it’s just a hemangioma, but don’t ignore it.

A cutaneous hemangioma is a benign neoplasm (growth) on the skin that looks a lot like a blood blister (angiokeratoma). That makes sense, because hemangiomas are vascular lesions, formed by endothelial cells, which are the cells that form blood vessels. The color can vary from red to black, and the lesion can ulcerate. A hemangioma can grow, making it prone to bruising, laceration, and infection.

The cause of hemangiomas is idiopathic (unknown). These growths usually don’t appear until at least middle age. Thin-skinned, light-colored breeds often experience hemangiomas. You’ll most likely find a hemangioma on the dog’s trunk or legs, especially hairless areas like the lower abdomen.

hemangioma on dog skin

Having your veterinarian remove the hemangioma via surgical excision or cryosurgery is often the best option.

“Because these are very vascular, they may ulcerate and drain. In those cases, you need to keep the area clean and consult with your veterinarian on a topical antibiotic or wound cream,” advises Debra M. Eldredge, DVM, a veterinarian in Vernon, New York.

Skin Cancer Signs on Dogs

Any new lump or growth on your dog is a call for an immediate veterinary exam. While chances are greater that it’s benign, there’s still a strong risk that it is not. Because some cancers appear on the skin only after invading internal organs, time is of the essence. While the classic sign of skin cancer is a lesion that just won’t heal, other symptoms to watch for include bleeding, change in color, crusty look or layer, inflammation, itchiness, swelling, or a wart-like appearance.

Diagnosing Hemangiomas

It is debated in veterinary literature whether hemangiomas are more accurately categorized as a neoplasm or simply a vascular malformation. One thing is certain: Hemangiomas are not malignant. The problem, however, is that they closely resemble an aggressive cancer called hemangiosarcoma. By the time a hemangiosarcoma is seen in the skin, the cancer has usually spread to the dog’s organs.

A veterinarian will not be able to tell you if the growth is a hemangioma or a hemangiosarcoma just by examining it; a biopsy, or at least a cytology, is required. “To be completely sure which type of tumor you are dealing with, a biopsy is best. In most cases your veterinarian will do an ‘excisional biopsy,’ totally removing the growth,” says Dr. Eldredge.

In a cytology, cells from the neoplasm are removed with a needle, sent to the laboratory, and examined under a microscope by a pathologist. While a cytology is less invasive than a biopsy, the results aren’t as conclusive and can be misleading, so a biopsy is preferable for diagnosis.

Depending on the size, location, and depth of the lesion, the biopsy may be done with a local anesthetic and a sedative, or it may require the dog to be fully anesthetized. “A local is fine,” says Eileen Fatcheric, DVM, owner of Fairmount Animal Hospital in Syracuse, New York. “They just can’t be on a super sensitive or movable part of the body, like near the eyes. Some areas, like a toe, can be difficult with just a local.”

The lesion will be sent to pathology for an analysis. The biopsy results will confirm or rule out the presence of cancer.

Waiting for a lump to go away on its own can prove to be a costly mistake. The sooner a diagnosis can be made, the better, especially if you have to move forward with treatment.

Learn about other abnormal skin conditions on dogs here.

Cynthia Foley is a freelance writer and dog agility competitor in New York.