Are black warts on dogs cancerous
Warts in Dogs
What Are Dog Warts?
Canine viral papillomatosis sounds serious, doesnt it? But the term is just a technical description for warts (papillomas) in dogs. While a diagnosis of dog warts is rarely serious, the condition is worth your attention, primarily so you dont confuse warts in dogs with other, nastier diseases.
Any dog can get warts, but they are more common in dogs who are immunosuppressed or spend a lot of time around other dogs. Young dogs frequently get warts in their mouths, while the skin of older dogs is more frequently affected. Certain breeds also seem to be at an increased risk of dog warts, including:
Symptoms of Dog Warts
Warts on dogs often look like a small head of cauliflower, but other, rarer types do exist, including an inverted papilloma (usually a firm lump with a dot in the middle) and dark, scaly plaques of skin that have an irregular surface.
Warts can develop in and around a dogs mouth, around the eyes, between the toes, and almost anywhere on the skin.
Some dogs develop one or just a few warts that are so small they are easy to overlook. In other cases, entire regions of a dogs body may be covered with warts of varying sizes. Warts in and around a dogs mouth may make it difficult for a dog to eat and drink normally. Warts on a dogs feet can cause lameness, particularly if the area is injured or becomes infected.
What Causes Dog Warts?
Warts in dogs are caused by infection with papillomaviruses. Many different types of canine papillomaviruses have been identified, and each type tends to cause a particular form of the disease (for example, warts in and around the mouth versus warts affecting the feet).
Dogs with warts are contagious to other dogs, but not to other animals or people. Once a dog has been infected with one type of papillomavirus, they are immune to that typebut not to others.
Papillomavirus can live in the environment for weeks, so its possible for a dog with warts to leave the virus behind in a particular area, leading to another dog contracting the virus from that location later. Papillomaviruses enter the body through a break in the skin, and infection develops when a dogs immune system cant fight off the virus before it takes hold. It generally takes four to six weeks for warts to develop after a dog is infected with papillomavirus.
How Veterinarians Diagnose Dog Warts
In most cases, a veterinarian can diagnose a dog wart with just a physical examination. If there are any questions about the diagnosis, the veterinarian can remove a sample of tissue and send it to a pathologist for identification.
Treating Dog Warts
Warts generally disappear on their own over six to eight weeks or so as the dog develops immunity against the virus. However, there are times when veterinary treatment is necessary:
Sometimes dog warts are so numerous, large, or located in places that result in secondary symptoms like lameness, difficulty eating or drinking, or eye irritation.
Warts may bleed or become infected with bacteria.
In rare cases, warts that fail to resolve on their own can turn into cancerous tumors. In general, warts that are present for more than three to five months should be treated.
Dogs who are taking immunosuppressive medications or have other, serious health conditions may be unable to get rid of warts without help.
If just a single or small number of warts is of concern, surgical removal is the treatment of choice. This can be done with a scalpel, laser, or through cryosurgery (using intense cold to destroy the wart).
Medications are often necessary when a large number of warts are causing problems for the dog. Unfortunately, its difficult to assess how effective these treatments are since most dog warts disappear on their own. However, the following treatments have been tried by veterinarians:
Interferon: an oral or injectable medication that stimulates the immune system
Imiquimod: a topical antiviral and antitumor medication
Cimetidine: an oral medication that may have a positive effect on the immune system
Azithromycin: treatment with this oral antibiotic appeared effective in one study
Immunostimulation: giving a vaccine made from a dogs own warts or Immunoregulin (a suspension of killed Propionibacterium acnes bacteria) can stimulate the immune system to respond against the virus
Reduce immunosuppression: if possible, discontinue or reduce the dose of immunosuppressive drugs and more aggressively treat any diseases that are having an adverse effect on the dogs immune system
Preventing the Spread of Dog Warts
There are a few things you can do to help protect your dog from developing warts. Obviously, do not let your dog play with or have any contact with dogs who have visible warts. If the protective nature of your dogs skin is compromised (from wounds, rashes, etc.) or their immune system is not functioning normally, do not take them to areas where other dogs congregate like parks, doggy day cares, and kennels.
And if, despite your best efforts, your dog does develop warts, keep them isolated from other pups until all the warts have disappeared.
Featured Image: iStock/Rawpixel
WRITTEN BY
Jennifer Coates, DVMVeterinarian
Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary...
Dog Skin Cancer: Types, Symptoms, and Treatment
The word cancer instills fear into the heart of every dog owner, but not all growths are cancerous. The most common growth found on dogs are lipomas, which are fat cells. Also commonly found on dogs are sebaceous cysts, which can become cancerous. If your veterinarian has diagnosed your dog with skin cancer, or if you are concerned that your dog might have a cancerous skin tumor or lump, it is understandable to feel worried and fearful.
Your veterinarian is your best resource to help you through any questions you may have about your dogs health and skin issues. However, here is some information you need to know about skin cancer in dogs to help you understand your dogs possible condition.
Can Dogs Get Skin Cancer?
Dogs can get skin cancer, just like we can. In fact, skin tumors are the most commonly diagnosed type of tumor in dogs. This is partly because skin tumors are easier to see with the naked eye than other types of tumors, and partly because the skin is exposed to more of the environmental factors that can cause tumors, such as chemicals, viruses, and solar radiation, then your dogs internal structures. Luckily, this also means that you and your veterinarian have a better chance of catching your dogs cancer before it progresses past available treatment options.
Causes of Skin Cancer in Dogs
Skin cancer can have a variety of causes. Just like with people, genetics play a large role in which dogs are more likely to get skin cancer. In fact, it is believed that genetics are the number one factor in the risk of a dog getting skin cancer. Triggers that may lead to a dog developing skin cancer include too much exposure to the sun, chemicals in the environment, hormonal abnormalities, and certain types of viruses.
Types of Skin Cancer in Dogs
There are several different types of skin cancer in dogs, just like there are several different layers of the skin. Each layer and skin component can develop distinct tumors, some of which may turn out to be cancerous.
Some of the more common types of skin cancer in dogs are:
- Malignant melanoma
- Mast cell tumors
- Squamous cell carcinoma
- Histiocytic cell tumors
- Fibrosarcoma
Malignant Melanoma
Melanomas can be either malignant or benign. These tumors are often dark-pigmented or can lack pigment. While benign melanomas are more common, malignant melanomas are a serious concern, as they grow quickly and have a high risk of metastasis (spreading to other organs).
Malignant melanomas are most commonly found on the lips, mouth, and nail beds. According to some researchers, the head, neck and scrotum areas are also moderately predisposed to skin cancer. Certain breeds, for example Miniature and Standard Schnauzers and Scottish Terriers, are at an increased risk, and males appear to be affected more than females.
Malignant melanomas look like raised lumps, often ulcerated, and can also look like gray or pink lumps in the mouth. Nail bed malignant melanomas, on the other hand, show up as toe swelling and possibly even loss of the toenail itself and destruction of underlying bone. Nail bed and footbed tumors often develop a secondary infection, leading to a misdiagnosis. These types of tumors usually metastasize to other parts of the body, decreasing the chances for a good outcome.
Mast Cell Tumors
Mast cell tumors are the most common types of skin cancer tumors. Mast cells release histamine, which is the chemical that causes some of the symptoms of allergic reactions in dogs, like irritation and itching. Mast cell tumors are cancer of these cells, and they can grow anywhere on your dogs skin, as well as in internal organs. The most common sites for mast cell tumors are the limbs, lower abdomen, and chest. About of mast cell tumors are found on dogs limbs.
Boxers, Pugs, Rhodesian Ridgebacks, Boston Terriers and older mixed breed dogs seem particularly susceptible to mast cell tumors, which most commonly affect dogs ages 8-to-10 years old. This cancer can be difficult to deal with, and your dog could have symptoms associated with toxins released from malignant mast cells, such as stomach ulcers, resulting from histamine release.
Squamous Cell Carcinoma
Skin squamous cell carcinoma is the most commonly diagnosed carcinoma of the skin, and primarily affects older dogs, especially Bloodhounds, Basset Hounds, and Standard Poodles. These tumors typically show up on the head, lower legs, rear, and abdomen, and appear as raised patches or lumps that are firm to the touch.
Exposure to the sun can be a cause of squamous cell carcinoma, but according to the National Canine Cancer Foundation, In dogs, the theory of exposure to sun is less obvious. It is believed that there may be some association with papilloma virus.
These tumors usually appear on your dogs abdomen, which is the area least protected from the sun by hair.
Histiocytic Cell Tumors
Histiocytic cells are a type of skin cell. When these cells proliferate into tumors, they are classified as histiocytic cell tumors.
These types of tumors are relatively common and typically affect dogs under 3 years old, especially Scottish Terriers, Bulldogs, Greyhounds, Boxers, Boston Terriers, and Chinese Shar-Pei.
There are three types of histiocytic cell tumors: histiocytomas, which are the most common; systemic histiocytosis, which mainly affects Bernese Mountain Dogs; and malignant histiocytosis, which also mainly affects Bernese Mountain Dogs and first shows up in the internal organs.
Fibrosarcoma
Fibrosarcoma and spindle cell tumors originate in the connective tissues of the skin and beneath the skin. These tumors can have a varied appearance, and while they are typically slow growing, they do tend to recur after surgical removal. Luckily, this type of tumor rarely metastasizes.
Fibrosarcoma usually affects dogs when they are middle-aged or older, with an average age of 10 years. Sometimes, an aggressive type of fibrosarcoma can affect young dogs. Your veterinarian will send off a sample of the tumor to a pathologist to determine whether or not the tumor is a low- or high-grade tumor, a classification that refers to the rate of cell division. This will help them give your dog an accurate prognosis and determine the best course of treatment.
This type of tumor is often found on the limbs. In addition to invading nearby structures, sometimes impeding their function, the tumors can also bleed, ulcerate, and become infected.
Symptoms of Skin Cancer in Dogs
The symptoms of skin cancer vary depending on the cancer, but in general, the best thing you can do to catch skin cancer early is to keep an eye on any strange lumps or bumps on your dogs body, especially as he ages.
Not all skin tumors are cancerous, and some, like skin tags, are usually benign sebaceous cysts or lipomas. However, if you discover an unusual lump or area of discoloration, play it safe and contact your veterinarian. Changes in the size, shape, color or ulceration of any growth or lump are also a cause for concern.
Diagnosing Skin Cancer in Dogs
Dog skin cancer is diagnosed by examining the cells of the skin tumor or lesion. Your veterinarian may perform a procedure called a fine needle aspiration, which takes a small sample of cells, or a biopsy, which removes a small portion of the tumor tissue or lesion by surgical incision. These samples are usually sent away to pathology for evaluation in order to obtain an accurate diagnosis.
Skin Cancer Treatment Options
A diagnosis of cancer for your dog is scary. Many types of skin cancer are treatable if caught early on, but it is understandable to feel worried.
Your dogs prognosis and treatment options will depend on a few factors, including the type of tumor, the location of the tumor, and the stage of the cancer.
Some skin tumors can be removed surgically to great effect. Others may require additional steps, such as radiation or chemotherapy.
Some types of cancer, for example malignant melanomas, are resistant to radiation therapy, while others, such as mast cell tumors, are more sensitive. Your veterinarian may refer you to a veterinarian oncologist when you have a cancer diagnosis. Veterinary oncologists have advanced training in cancer treatment.
Preventing Skin Cancer in Dogs
Some types of diseases are preventable, while others are not. As in humans, many cancers are the result of a genetic predisposition. In other cases, cancer is the result of a variety of factors coming together in an unlucky configuration, but there are a few things you can do to lower your dogs risk.
The risk factor most in your control is exposure to sunlight. If you have a light-skinned, short-haired dog breed, limiting your dogs exposure to direct sunlight, especially during the peak daylight hours, may help lower his risk of skin cancer.
The most important thing you can do to help your dog avoid skin cancer, however, is to familiarize yourself with all your dogs lumps, bumps, and rashes, perhaps during your daily grooming routine, and consult your veterinarian if you notice anything suspicious.
