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Canine Histiocytoma

Canine Histiocytoma

Canine histiocytoma is a benign skin tumor, mostly observed in young dogs, and goes way on its own within 3 to 4 months. Find more information about this non-cancerous tumor.
Nicks J
Last Updated: Jan 22, 2018
Canine histiocytoma is a non-cancerous skin growth that commonly occurs in young adult dogs. This tumor is a rounded eroded growth, but is not a skin cancer. Although histiocytoma can affect dogs of all ages, the incidence of this skin tumor is more frequent in canines less than 4 years old. Histiocytoma is common in certain breeds that include Boxers, Dachshunds and Labradors. Even bulldogs face a greater risk of getting this benign tumor.

As the skin tumor is non-malignant, it does not cause any harm and there is no need to worry about it. This raised, hairless lump often appears suddenly, without prior warning. The good news is that the skin growth goes away on its own, without causing any problem. In other words, the tumor is not a serious condition. At the most the skin growth may cause a minor skin infection, that can be easily treated at home. In most cases, a visit to a veterinarian is not essential to treat this condition as it subsides by itself within 3 months. However, pet owners are likely to get scared after seeing histiocytoma as they are ugly and appear as red colored protruding mass of tissue. These unsightly histiocytomas that pop up suddenly on the dog's skin are scary especially when they occur at multiple places and are abnormally large in size. Usually, a single histiocytoma is seen in dogs that in most cases occur on the neck, head, ears or the left paw.

Although it may appear that histiocytoma is restricted to the outermost layer of the skin, it is not so. The abnormal cells that form the histiocytoma penetrate well below the inner layers of the skin, yet the popped up unsightly mass disappears in 2-3 months' time.


To make sure that the tumor developed is non-cancerous (benign), a biopsy is done. Looking at the biopsy report the veterinarians will be able to determine whether the skin growth is malignant or not. Biopsy is the best way to confirm a cancerous growth. In this procedure, a small piece of the round eroded growth is snipped off and sent to the laboratory for further analysis. In the laboratory, the small piece of tissue is examined under a microscope. A microscopic examination of the tissue will help to know what exactly is the growth. A local anesthesia is given to the affected dog, before performing the biopsy. This is done so that the dog does not feel the pain, while removing the tissue.

Another option to take out the cells from the tumor is by using a needle or one can simply collect the cells from the tumor surface and observe them under the microscope. This method, however does not allow to view the architecture of the tissue in question. But, with the cells available for examination, one can confirm the identity of the tumor.


Histiocytoma can be surgically removed, and is the fastest way to get rid of this non-cancerous tumor. In most cases, the skin growth is small and will not require much efforts to remove the tumor. The procedure is simple and easy to perform. Sometimes easy removal of the tumor is not possible, in case it is developed in a location very close to the eye or ear flaps. In such circumstances, surgery is not performed and the abnormal growth is allowed to subside on its own. In case the tumor causes secondary bacterial infection, surgical intervention is required. Skin irritation is a common problem in this condition, but topical treatment that contain DMSO and a cortisone derivative, is useful to control the symptoms of irritation. Regression (retardation of growth) of canine histiocytoma, is spontaneous in majority of the dogs affected.

It is observed that the vets often take a 'wait and watch' approach before opting for surgery to get rid of histiocytoma. In case, the abnormal growth shows signs of enlargement within a week or two, doctors recommend surgical removal of histiocytoma. Even if the histiocytomas are moderate in size and not growing with time, pet owners still request for surgical intervention. This is because, histiocytoma are unsightly and as a pet owner, you may get irritated seeing your dog roaming with this abnormal lump on the affected area. Also, over time, histiocytomas become itchy and so the dog to relieve the itchiness tends to scratch and lick the affected area. However, this may increase the risk of secondary infection and complicate the matter. Hence, surgery is regarded as the right approach to get rid of histiocytoma in dogs at the earliest.

Most dog owners are alarmed after seeing the skin lump as it appears red. However, histiocytoma in dogs is not painful and does not affect the mobility of the dogs. So, once the diagnosis confirms the presence of histiocytoma, rest assured, your dog's health is not a cause for concern.

Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a veterinarian.
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