Table of Contents
You might have not given much thought to it, but cancer is widespread among dogs. But how do you recognize cancerous tumors like melanoma in dogs?
A dog can be a wonderful addition to any family. But before bringing one into your life, it is important to know how to take care of it.
Caring for a dog is a big responsibility that should not be taken lightly. This means you need to fulfill its needs and ensure your pet is happy.
Aside from providing nutritious food and safe home, there is no higher priority than ensuring your pup’s health.
Whether mixed or purebred, all dogs are at risk of developing cancer. According to the American Veterinary Medical Association, dog cancer is at roughly the same rate as in humans.
This means that just as in humans, dogs can develop many types of cancer such as lymphoma and osteosarcoma. But today, we will be focusing on melanoma in dogs.
Melanoma in Dogs
It is a common type of skin cancer in dogs that involves tumors originating from melanocytes.
Melanocytes are skin cells responsible for producing a pigment called melanin, which gives the skin, hair, and eyes their color. Melanoma happens in the form of a nodule or a mass when there is an abnormal production of melanocytes.
Commonly found as lumps, these tumors will affect different parts of the body since they have a high tendency of spreading. As they continue growing, the tumors tend to bleed.
Either benign or malignant, melanoma in dogs can develop in the skin, eyes, lips, toenail beds, and other unusual places in the body.
The most common sign of canine melanoma is a black or brown mass, but some are not pigmented and may appear as a pink lump.
Dogs of any breed can be affected but are more commonly seen in Cocker Spaniels, Poodles, and Chow Chows.
You may wonder what causes this skin cancer when dogs have hair to protect them from the sun. Well, you should know that sun damage to the skin can be a factor but not necessarily the cause of all varieties of dog skin cancer.
Given that the majority of dogs have a lot of hair, light exposure is less likely to cause melanoma in dogs.
Although no one exactly knows why melanomas develop, it seems that the causes are the environment, hormonal abnormalities, viruses, or simply hereditary of those developing the disease.
RELATED: 10 Environmental Causes of Cancer in Dogs
Difference Between Benign Melanoma and Malignant Melanoma
Melanoma tumors can behave in different ways. Though difficult to predict, doctors can forecast the behavior of the tumor with its location, thickness or depth, and the properties of the cancerous cells.
Benign melanoma in dogs tends to grow slowly and ranges in size from very small to more than 2.5 inches in diameter. It may be red, gray, brown, or black and appears on areas of the skin covered with hair.
While benign melanomas are more common and readily curable, malignant melanomas are a serious concern, as they are extremely aggressive.
Malignant melanoma in dogs tends to grow quickly and spread readily to distant tissues and other organs. Highly invasive, it can arise anywhere but more often occurs in the mouth, on the lips, and in the toenail beds.
While treatment depends on the progression of the disease, surgery, chemotherapy, and radiation are strongly suggested to improve the chance of survival.
The canine melanoma vaccine has also been shown to be effective as an additional systematic treatment.
Diagnosis of Melanoma in Dogs
This skin cancer in dogs can be diagnosed by cytology based on the presence of melanin granules and each cell’s characteristics. However, it is not always diagnostic and thus may require other examination.
So, the diagnosis of melanoma in dogs is based upon a fine needle aspiration, which is a type of biopsy procedure.
The doctor uses a syringe with a very thin, hollow needle into the affected area to take out a small sample of cells.
But if it does not provide a definitive diagnosis, specialists will surgically collect a piece of tissue from the mass.
Before the surgery, they will evaluate the health of the dog’s internal organs by doing a complete blood count and urine testing.
Treatments of Melanoma in Dogs
Surgery is the treatment for melanoma in dogs. Typically benign, a mass develops in the haired skin and only requires conservative surgical removal.
Although in certain cases, an oncologist may recommend doing chemotherapy every 3 weeks. Most patients tolerate the treatment with mild side effects lasting only a short time.
In addition, radiation therapy prevents or delays the regrowth of a tumor after it has been removed. Such treatments require administration twice a week.
Furthermore, a melanoma vaccine is conducted through a series of injections to help the body kill any remaining tumor cells. Reportedly, the vaccination gives excellent long-term control of the disease and survival rate with minimal to no side effects.
As with most cancers, there is no known approach to preventing melanoma in dogs. Treatments focus on both controlling the tumor as well as addressing the concern for metastasis.
Clinical Presentation of Dog Skin Cancer
The biological behavior of the tumor can vary tremendously with its location. So, in this article, we will discuss its occurrence in many locations of the body.
Oral Melanoma in Dogs
Melanoma in dogs also happens within the oral cavity. It can develop along the gums, lips, and other parts of the mouth.
Commonly in older and male dogs, oral melanoma occurs in darker areas of pigmentation in the mouth.
It can penetrate deep into the bone and spread in up to 80% of dogs, making it the most common type of cancer in canines.
Mouth cancer in dogs has the potential to spread to the lungs and lymph nodes. Either benign or malignant, the oral tumor usually continues to grow to cause discomfort and difficulty in eating.
The most common sign of oral melanoma in dogs is the noticeable swelling in the mouth. Other symptoms may include bad breath, drooling, unwillingness to chew hard food, or worse, blood coming from the mouth.
Since the tumor is invasive, enlargement of the lymph nodes may be a sign of it spreading rapidly. If the tumor has spread to the lungs, your dog may have difficulty in breathing, weight loss, and poor appetite.
Fine needle aspiration may be performed to determine the presence of any abnormal cells that may indicate melanoma.
A biopsy, taking a large portion or removing the entire tumor, may be recommended for the veterinary pathologist to examine the tissue and make a diagnosis.
Mouth tumors in dogs will require surgery to remove the melanoma in the oral cavity. This means a portion of the jawbone has to be removed with the tumor to achieve control of the disease.
Canine oral melanoma also tends to be very responsive to radiation therapy. Such treatment has been reported to have excellent control of oral melanomas but should be used in conjunction with the vaccine for improved survival times.
Nailbed Melanoma in Dogs
The second most common location is the nailbed which occurs in up to 20% of dogs.
Also known as subungual, nailbed melanoma in dogs may not be straightforward to recognize. Thus, knowing what it looks like will be important to have a better prognosis when detected at an early stage.
Dogs with this disease will have a dark brown or black colored mass on the toe. This lump is the common and most obvious sign.
A melanoma that involves the toenail bed initially appears to be an infected toe. Since antibiotics cannot resolve the problem, eventually, the affected foot begins to swell, bleed, or produce pus causing lameness.
If the tumor is on the toenail bed, amputation of the entire toe is necessary because it has a more aggressive progression. This surgical treatment can involve more than one toe.
If there is evidence of spread, the lymph node on the affected leg may be removed as well. Then, chemotherapy or radiation will treat the cells that were left behind.
Ocular Melanoma in Dogs
There are two kinds of ocular melanomas in dogs, limbal and uveal melanoma.
Sometimes called epibulbar, limbal melanomas are less common and may develop in the marginal region of the cornea.
On the other hand, uveal melanomas are the most common primary intraocular tumor in dogs. They grow from the tissues that make up the uvea (the ciliary body, choroid, and iris).
While limbal melanoma is benign, about 80% of uveal melanoma is also non-cancerous, and the risk of metastasis is less than 5%.
Both may tend to grow slowly, but if left untreated, they can seriously compromise the function, health, and structure of the eye.
There are no environmental factors known to cause eye tumors in dogs, but there is evidence that it is at least in part heritable and the result of genetic mutations.
To diagnose this cancer, the veterinarian will perform a full physical examination followed by a complete ophthalmic checkup.
For uveal melanoma in dogs, if there is growth, the mass may be taken out with the surgical removal of a certain part of the iris. You can also opt for laser surgery to retain both the eye and vision.
In cases of fast-growing and invasive melanomas, the surgical removal of the eye is always advised. It is curative and generally recommended for serious tumor-related complications.
For limbal melanoma in dogs, the tumor grows slowly, so it is usually monitored. If it grows rapidly, the required surgery will extract the tumor which may include the removal of a certain part of the cornea.
FAQs about Melanoma in Dogs
How long do dogs live with cancerous tumors?
Melanoma in dogs is fatal since it can be an aggressive cancer. 30 to 40 percent of malignant melanoma rapidly spreads in the early stages attacking the lungs, lymph nodes, and other organs.
So, the average lifespan of an affected dog s is five to eight months. Thanks to advances in early recognition, diagnosis, and treatment, pets today have a better chance of survival than they did before.
What do you do with dog cancer, such as melanoma in dogs?
Surgery, chemotherapy, and radiation are the treatments for canine melanoma.
While there is no preventive care, research gives hope for a cure in saving our furry friends’ lives.
Canine cancer has been a huge part of the AKC Canine Health Foundation’s research for years to better understand dogs’ possible conditions.
The organization’s commitment is to help dogs live longer lives by helping dog owners with the treatment options available.
How aggressive is dog skin cancer?
Malignant melanoma in dogs is not only highly invasive but also tends to spread rapidly to distant tissues and even attack organs. It can be unpredictable and grow at various rates.
You will know if your dog has melanoma if there are indications such as bumps or lumps on the lips, mouth, toenail beds, or pads of feet.
Melanoma in Dogs: Final Thoughts
Our dogs depend on us to look after them. We also understand that you want to make sure you are doing what is best for your ball of fluff.
While taking good care of your fur baby can decrease the risk of problems, there are still numerous reasons for it to get sick. If you have any concerns about certain conditions in your pet, you may wish to speak to your vet.
Melanoma in dogs is easy to see with the naked eye. This means that you and your vet have a better chance of catching your pet’s cancer before it advances past treatment options.
On matters of health, always consult your veterinarian to make the best recommendations. Your doctor will be your greatest resource to help you with your pup’s health and skin issues.
Remember, dogs don’t get to tell what they feel. So as owners, we do what we think is best for their well-being.
