Melanoma and moles in dogs

Melanoma and moles in dogs

Health & Safety

Most people have at least one mole somewhere on their bodies, and most people have several of various shapes and sizes! As we all know, it is important to monitor moles and be alert to any new moles that develop, or changes in the shape, size, texture and other factors of moles, as they can occasionally be cancerous.

However, humans are not the only animals that commonly have moles-dogs often do too, although you may not even realise if your dog is among them, as they will tend to be hidden by the dog’s fur. As is the case with people, the vast majority of moles in dogs are perfectly benign and simply a feature of your dog’s skin-but moles on dogs can potentially become cancerous just as human moles can.

Getting to know your dog’s skin and coat can help you to identify any moles that your dog has and so, be able to spot if any new ones develop or if an existing mole is changing, and this is certainly a good idea for all dog owners in order to spot any changes early on.

In this article, we will look at melanoma moles in dogs in more detail, including how to identify a problem, what sort of dogs are at greatest risk of melanoma, and what can be done to treat them. Read on to learn more.

What is melanoma?

Melanoma is a type of skin cancer, and when a mole becomes malignant, this will almost certainly be the cancer responsible for the change. As mentioned, most moles are not cancerous and few moles will develop malignancy at any stage during the dog’s life, but because melanoma or skin cancer is one of the most common types of cancers to affect both dogs and people, being vigilant to potential signs of problems is important.

Why do some moles become malignant?

There is no definitive answer to the question of what causes a mole that the dog has had all of their life to become malignant later on, although there are certain factors that can contribute to the problem.

As melanoma is a type of skin cancer, dogs that are exposed to direct sunlight (particularly in the summer) regularly over a period of time (usually years) are more at risk of moles becoming cancerous, particularly if the mole is in an area not covered by fur.

Light-coloured, thin or fine fur also increases the risk of malignancy, as does light-coloured skin, due to the darker dogs having better natural protection from the sun. Additionally, the risk factors for mole melanoma in dogs increase exponentially for every year that the dog ages, with older dogs being much more likely to develop problem moles than their younger counterparts.

Dogs that have their fur shaved or clipped very short during the summer for several years in a row may also be at higher risk of a mole turning malignant, as this will of course increase sun exposure.

Keeping your dog covered up, using sunscreen on them and of course, leaving their coat intact can all help to prevent problems of this type. Hairless dogs like the hairless variant of the Chinese Crested breed require particular vigilance from their owners in terms of sun protection and avoiding sunburn, for these reasons.

Identifying a problem

To begin with, it is wise to get to know your dog’s skin and so, what it normal and where any moles are by grooming and examining them regularly, ensuring that you part the hair right down to the skin instead of just brushing the surface layers! This will help you to locate existing moles and so, know where to look when checking them, as well as ensuring that you will pick up on any new moles that form early on.

It is important to note that generally, moles are not a problem for dogs, and it is not hugely common for them to become malignant-also, that melanoma is just one form of malignancy that moles can develop, and others exist too.

When you are examining your dog’s moles or have spotted a new one, keep an eye out for the following indications that the mole may be changing and so, potentially have become malignant:

  • Changes to the texture of the mole; for instance, if it was previously smooth but has become roughened.
  • Hair growth from a mole that was previously hair-free.
  • A mole that was previously flat becoming slightly raised.
  • Darkening or other changes in the colour of the mole.
  • The mole becoming larger and wider.
  • The borders of the mole changing from clearly defined to more ambiguous in terms of where the mole stops and the rest of the skin begins.
  • Any bleeding or weeping from the mole.

It is important to remember that changes of these types do not always mean melanoma-but they do mean that your dog should be checked out by your vet.

Treating melanoma moles in dogs

If you spot any changes like these, take your dog along to the vet. They will perform a physical examination and usually, take a biopsy of the mole to confirm diagnosis or identify the root cause.

Generally, melanoma moles that are identified in a timely manner can be surgically removed with relative ease, although in severe cases in which the cancer has metastasised to other parts of the body, treatment can be more challenging.

Newsletter icon
Get free tips and resources delivered directly to your inbox.


Pets for StudWanted Pets

Accessories & services


Knowledge Hub


Support & Safety Portal
All Pets for Sale