As dog owners, it’s natural to feel concerned when you discover a lump on your dog.

Whether it's a soft, fatty growth or a firm bump under the skin, any unusual swelling can be alarming.

At Tooronga Veterinary Hospital, we regularly see pets with various types of skin lumps, and while many are benign, some do require closer attention.

In this blog, we’ll explain:

The common types of lumps and bumps on dogs
When to seek veterinary advice
How we diagnose and treat them
Which dog breeds are more prone to lumps
When it’s time to worry

Common Types of Lumps on Dogs

Dogs can develop a wide variety of skin growths throughout their lives. These include:

1. Lipomas (Fatty Tumours)

One of the most frequently diagnosed skin lumps in dogs, especially in middle-aged to senior pets. These soft, round, and typically slow-growing masses most commonly develop just beneath the skin, often around the chest, belly, or upper legs.

While benign and usually painless, lipomas can become large or interfere with movement, in which case surgical removal may be recommended.

2. Sebaceous Cysts

These occur when a hair follicle or oil gland becomes blocked, leading to a small, firm lump under the skin.

They can rupture, releasing a thick white or yellowish discharge that resembles cottage cheese.

While most are harmless, they can become irritated, infected, or uncomfortable, and may require surgical removal by a vet.

3. Warts

Common in young dogs under the age of two. Warts are often virally induced (by papillomavirus). The virus is contagious and is spread via direct contact or indirect contact such as sharing water bowls at coffee shops.

These growths are typically harmless, though they can become problematic if they’re in high-friction areas or are frequently licked or scratched.

4. Abscesses

An abscess is a painful swelling caused by bacterial infection, often following a minor wound or a grass seed.

These lumps are typically warm, soft, and may swell rapidly. They can burst and ooze pus if untreated.

Abscesses must be drained and treated with pain relief and antibiotics.

5. Mast Cell Tumours

One of the most common forms of skin cancer in dogs and can appear deceptively similar to benign lumps. They might be soft or firm, small or large, and can change in size rapidly - they may shrink and then grow over the course of a couple of days.

Mast cell tumours can be aggressive and unpredictable; therefore, early diagnosis and treatment is essential.

6. Histiocytomas

These skin growths are non-cancerous, and they usually affect younger dogs under three years of age.

They look red, raised, button-like lumps often appear suddenly (commonly on the head, ears, or legs) and tend to resolve on their own over a few weeks.

Despite their benign nature, they should still be examined by a vet to rule out more serious conditions.

When Should You See the Vet?

It’s always safest to have any new skin growths on your dog checked by a vet, especially if you notice:

A lump growing quickly
Ulceration, bleeding, or discharge
A pigmented lump (black or dark brown in colour)
A change in shape, colour, or firmness
Your dog is licking or scratching it constantly
Weight loss or changes in appetite

If you live in Melbourne, book an appointment with our team at Tooronga Veterinary Hospital. An early assessment can prevent complications and gives you peace of mind.

How Are Lumps Diagnosed?

We use several techniques to assess lumps on dogs, including:

Physical Examination: Initial check for appearance, size, texture, and location.
Fine Needle Aspiration (FNA): A quick, non-invasive procedure to extract cells for lab testing.
Biopsy: For larger or suspicious lumps, a small tissue sample is taken under sedation or general anaesthetic.
Bloodwork & CT scanning: If we suspect internal involvement or spread, we may offer further tests.

Diagnosis helps determine whether the growth is benign, malignant, or infectious.

What Can Be Done About Them?

Treatment depends on the diagnosis:

Benign growths: Often monitored or surgically removed if bothersome.
Infections or abscesses: Require antibiotics and sometimes drainage.
Cancerous lumps: May require surgical removal, chemotherapy, or referral to a veterinary oncologist.

Our Melbourne clinic is fully equipped to manage both simple and complex cases, ensuring your dog gets the best care possible.

Are Some Dog Breeds More Susceptible?

Yes. Certain breeds are more likely to develop skin lumps and tumours. Some of these breeds include:

Labrador Retrievers – prone to lipomas
Boxers, Pugs, Golden Retrievers and Bulldogs – higher risk for mast cell tumours
Cocker Spaniels – sebaceous cysts
Schnauzers – melanomas

Regardless of breed, age is a big factor, with senior dogs more likely to develop lumps.

Worried About a Lump or Bump?

Whether you’ve just noticed a small bump or are concerned about a suspicious lump, don’t wait.

Our veterinary team is experienced in diagnosing and treating all types of lumps and bumps on dogs.

Early evaluation can make all the difference. Book your pet’s check-up today and keep them happy and healthy for years to come.

Lumps & Bumps on Dogs