Lumps and bumps on dogs: found a lump on your dog?

Common causes of lumps on dogs

While it may be natural to suspect cancer if you find a lump on your dog, cancerous growths aren’t the only cause of lumps and bumps – sometimes described by your vet as ‘masses’. 

Benign, or harmless masses that are common in dogs include warts, skin tags, cysts, abscesses, granulomas and papulonodular dermatoses. Let’s look at those in turn. 

Dog warts and skin tags

Skin tags and warts are relatively common in dogs, and usually nothing to worry about. They’re small bumps that can occur in groups or on their own. Skin tags are usually more fleshy and bendy than warts, which tend to lie closer to the skin. 

Skin tags and warts on dogs are normally harmless and don’t usually need to be removed unless they become infected.

Dog cysts

A cyst is a round or oval lump on your dog’s skin that’s filled with liquid. They can occur at any age, anywhere on the body, and can affect all breeds of dog. While they’re not caused by infection themselves, they can become infected. 

Cysts can be removed by surgery or drained – when your vet makes a small incision or inserts a needle and drains away the fluid. 

Dog abscesses

An abscess is a pocket of pus beneath the skin, or within another bodily tissue. Abscesses are localised infections that usually develop after a wound has healed, which prevents the pus from draining. They’re often caused by puncture wounds – such as cuts and bites acquired through play fighting or foreign bodies like thorns. Dogs can develop abscesses at any age.

Abscesses can be painful, cause your dog to develop a fever, and occasionally split and release nasty-smelling pus. Your vet may recommend surgery to drain the pus and clean the infected area, sometimes together with a course of antibiotics to tackle infection.

Dog granulomas

A granuloma is a solid mass beneath the surface of the skin that’s made of inflammatory cells, blood vessels and connective tissue. Granulomas can affect dogs at any age, and are usually caused by long term infections or inflammation. The most common type of granuloma in dogs is the Acral Lick Granuloma cause by excessive licking of an area, most commonly the paws.

“While it may be natural to suspect cancer if you find a lump on your dog, cancerous growths are far from being the only cause of lumps and bumps.”

Tumours in dogs

Tumours are more common in older dogs, though it’s possible for younger dogs to develop them, too. If your vet suspects the lump on your dog may be a tumour, he or she will recommend taking a a sample either with a needle or surgical biopsy to confirm their diagnosis. This will allow them to decide what treatment is best for your pet. 

Tumours fall into two categories: malignant, which means they’re likely to spread or get worse, and benign, which means harmless, or non-cancerous. 

What next?

Whatever the likely cause of the lump, the most important thing is to get your dog checked out by your vet without delay, so he or she can recommend the best treatment and care for your dog.

Professional advice on lumps and bumps on dogs

For expert advice on lumps and bumps on dogs, speak to your local vet.

Find your nearest vet using our Find a Vet page, or speak to a vet online using Online Vets.