Can Dogs Get Melanoma?

Many of us will know someone either in our social circle or extended family who has had some form of skin cancer. The most common form of the disease is the melanoma, which is a tumor that grows on the surface of the skin, taking on a different texture and color than the skin surrounding it as it grows. There are various types of melanoma, with some kinds being relatively benign and not posing a threat to the person’s health and other kinds being highly aggressive and possibly life-threatening if they are left untreated. It is this variation in severity that can make the cancer highly dangerous, as what can at first appear to be a minor issue can quickly become a serious health problem. But while these tumors are relatively widespread in humans, is this true of dogs, who have their skin covered by a protective layer of fur?

YES!

The answer is yes, as there are far more factors which feed into the development of skin cancer than just simple direct exposure to contaminants. Furthermore, due to the fact that the animal’s skin is screened by the fur, you should seek veterinary assistance as soon as possible if you suspect that your dog has the disease. This is because there is often no way of knowing how long the cancer has been growing within the dog.

It can, at times, be difficult to distinguish melanomas from other types of common skin blemishes, though there are some distinctive symptoms that you can look for. The first of these is a slight amount of swelling around the lump itself, as the tumor will often irritate and displace the surrounding tissue as it grows. Additionally, the surface of the growth will commonly have variations in texture and color, which serves to differentiate them from regular moles or freckles, which will be mostly smooth and monotone in appearance. In more serious cases, you may see the dog begin to exhibit symptoms such as tiredness or lack of an appetite, which could indicate that the cancer has spread to other parts of the body.

Typically, melanomas in dogs are caused by genetic problems that are passed down through generations. This means that it is possible to perform tests on the dog’s DNA in order to predict the appearance of some types of the cancer. Additionally, exposure to carcinogenic substances can play a large role in the development of the disease.

To diagnose the problem, the vet will typically perform blood tests in order to detect the presence of cancer cells or specific antibodies manufactured by the immune system to fight the cancer. A biopsy sample can also be taken from the tumor to determine if it is malignant or not and if any further treatment is warranted.

For more information on the disease and how it is diagnosed, visit our condition guide at Malignant Melanoma in Dogs.

After your vet has diagnosed the dog with melanoma, there are two options available. The first is to simply leave the tumor in place. This is commonly done if the growth is benign, as it will pose no threat to the continued health of the dog and surgery to remove it will, therefore, be an unnecessary expense and risk. If, however, the tumor is malignant, then the vet will usually advise you to proceed with treatment. This can involve simply surgically cutting the growth out of the dog, and it can necessitate the use of chemotherapy to kill any remaining cancer cells that have spread throughout the body. This utilizes a cocktail of drugs to destroy any malignant cells in the dog, but can have some unpleasant side effects such as vomiting and loss of energy. Alternatively, bursts of high-intensity radiation can be applied to kill the tumor in a process known as ‘radiotherapy’, though this too can require remedial chemotherapy. In the aftermath of treatment, the dog will require plenty of rest in order to recover from the possible effects of surgery or chemotherapy. Dietary changes may also be needed temporarily, in order to help them cope with the side effects of chemotherapy drugs.

To read accounts from dog owners who have dealt with melanomas or to consult with our in-house vets, check out our condition guide at Malignant Melanoma in Dogs.

Despite the obvious physiological differences between different species, melanoma will often appear somewhat similar in its presentation and reaction to treatment.

• Cats and other small animals will also typically develop skin cancer as a consequence of flaws in their genetic structure. This is because their life cycle is short enough that they are able to reproduce and pass the problem on before the disease becomes serious enough to be lethal.
• Any animal that receives radiotherapy may also be offered an additional course of chemotherapy in order to make sure that no cancer cells have been missed that may later turn into tumors of their own accord.

There are some key differences between dogs and humans that you should keep in mind when trying to deal with this condition in a pet.

• Melanoma in humans is frequently caused by over-exposure of the skin to direct sunlight, which can cause the DNA in the cells to be damaged by ultraviolet radiation. This can then result in them growing out of control and forming a tumor. Dogs, meanwhile are mostly shaded by their fur.
• Generally speaking, medical professionals will be far more willing to directly operate on a dog than a human due to the differing reactions to scarring and disfigurement between the species. Instead, they will prefer to use radiotherapy or chemotherapy on people suffering from cancer.

A relatively young beagle is taken for a walk by its owner, during which they notice a particularly dark patch of skin on the back of the dog’s neck, due mainly to its short fur and white coat. Upon closer inspection, the patch of skin appears mottled in texture and hue. As the dog is still young the owner is troubled and decides to take the dog to be inspected by a vet. The vet performs a series of tests on the beagle’s blood and a sample taken from the growth. It is confirmed that the dog has melanoma, though it is still in its early stages and can be treated with surgery. The vet carefully cuts out the growth and the dog is able to return home the same day. After a few weeks of antibiotics and rest, the wound heals fully and they are able to resume their normal activity levels. The owner takes the dog back for occasional tests to make sure that no other instances of cancer have appeared and a year later the dog is still free of the disease.