Lumps and bumps on dogs

September 5th, 2013
lump and bumps on dogs, see your vet

Have you ever found a strange lump on your dog and automatically assumed the worst? As Tim Falk discovers, lumps and bumps on dogs can be for all sorts of reasons.

When Tracey McGown discovered a lump on the side of her gorgeous Golden Retriever Ruby, she immediately dreaded what it might mean for her pooch’s health. “As soon as you feel a lump you do get panicky that it could be something bad,” McGown says. Could it be something as simple as a tick, or something more sinister like cancer?

Despite McGown’s worry, however, a quick trip to the vet revealed the lump was simply a harmless fatty deposit and nothing to worry about.

When you discover a lump on your dog, it’s human nature to assume the worst — and for many people the worst means cancer. But, in reality, dogs get lumps and bumps for all manner of reasons.

So how can you tell if your dog’s lump is harmless or if it could be a sign of something more serious? “The basic rule is, if it is growing rapidly or bleeding it should be checked by a vet,” says Dr Peter Green from Heathmont Animal Hospital.

Dr Green says the two most common lumps in dogs are lipomas and sebaceous cysts. “Lipomas are fatty lumps under the skin, especially around the rib cage, common in middle-aged dogs. They are more common in overweight dogs but can occur in any dog. They are really like abnormal fatty tissue, although technically they are a benign tumour,” he says.

Most lipomas grow slowly but may reach a certain size and then not seem to grow at all. They usually range in size from a pea to an orange, but Dr Green did once remove a lipoma that weighed 5kg. “They are painless and rarely cause problems. If necessary they are easily removed by surgery,” he explains.

Sebaceous cysts are caused by a blocked oil gland. Some breeds, such as Poodles, are more prone to them. They often burst and extrude a waxy substance, and sometimes get infected and cause irritation. “My recommendation to clients is to remove them if the dog is having an anaesthetic for some other reason, such as a teeth scale,” Dr Green says.

What else could it be?

There are plenty of other reasons for our canine companions to develop lumps and bumps. Dr Rayya T-Malaeb, from Vets All Natural and a winner of an International Fund for Animal Welfare Action Award, says histiocytomas are benign tumours that mostly occur in younger dogs. They take the form of raised, hairless red lumps and look very similar to mast cells, which are very nasty tumours. “Generally they spontaneously resolve after a few weeks. I tend to prescribe antihistamines for patients with this type of lump as it will help reduce the irritation and itching associated with it,” Dr T-Malaeb says.

In recent times, Dr T-Malaeb has treated lots of dogs with abscesses secondary to grass seeds. “Your dog brushes against some dry grass and runs the risk of a grass seed attaching itself to your dog’s coat. This grass seed can then penetrate your dog’s skin and this will lead to the development of a fibrous capsule as your dog’s body will recognise the grass seed as a foreign object,” she says.

Abscesses can occur anywhere on the body and, as the grass seeds moves along, the capsule can get bigger and burst. “You must immediately attend to your dog if you notice any suspicious lump and get your local veterinarian to have a look. They often require a general anaesthetic, surgical drainage of the lump and a probe to see if a foreign body can be found,” Dr T-Malaeb says.

Finally, Dr Green also points out that swelling under a dog’s eyes is often a sign of tooth root abscesses.

The “c” word

Cancer. The mere mention of the word is enough to send a shiver down any dog owner’s spine. Sadly, in some cases those unexpected lumps and bumps on our dogs can turn out to be cancer — but that doesn’t always mean the news is as bad as many fear. “A cancerous skin tumour never indicates the death sentence,” Dr T-Malaeb says. “The prognosis is based on how quickly the tumour has been diagnosed and attended to. For the ones that have been picked up fairly early, the prognosis can be really good; however, it all depends on the type of tumour we are dealing with.”

Mast cell tumours are a relatively common cancerous lump in dogs. They are graded from 1 to 6, with the lower grades, which are more common, easily treated with adequate surgery. “Mast cell tumours can vary in appearance from just a lump under the skin to a red ulcerated lump,” Dr Green says, reiterating his advice that if a lump is growing rapidly it should be checked.

Soft tissue sarcomas are malignant tumours that can arise from cartilage, nerves, fat or even blood vessels. Responsible for about 15 per cent of all cancers in dogs, sarcomas can appear anywhere on or in the body. “The grading of this type of tumour is essential as a lower-grade sarcoma has a better prognosis than a higher-grade one. High-grade sarcomas also have a potential to metastasise (spread) and surgical excision alone may not be curative. Some patients may require radiation or chemotherapy treatment,” Dr T-Malaeb says.

Dogs that love to sunbake are prone to developing haemangiosarcomas, highly aggressive tumours which can spread to the internal organs if not immediately surgically removed. “This type of tumour resembles the ‘malignant melanoma’ that occurs in humans due to high exposure to UV light,” Dr T-Malaeb says. “In canines, it usually affects the furless areas like the abdomen, and white-coated dogs are more prone to developing it. Protect your dog with a registered canine sunscreen product and a summer coat.”

Cancer treatment

Cancerous lumps are diagnosed most often by needle aspirate or surgical biopsy. “A needle aspirate is quick and painless (usually) and is generally sufficient to determine if a lump is cancerous or not. A more precise diagnosis may need a biopsy,” Dr Green says.

Nowadays most cancerous lumps can be cured by surgery, although additional treatments such as chemotherapy or radiation may be necessary. “If a malignant lump has spread to lymph nodes or other parts of the body then the prognosis is more guarded. There are specialist vets who treat cancer patients with good success rates, although cost of treatment can be very high,” he says.

According to Dr Green, most vets who are comfortable doing surgery can handle the majority of cancerous lumps adequately. “Owners should discuss options with their local vet and see if referral to a specialist is a better option,” he says.

As you can see, the list of factors that cause lumps in dogs is a long one. While the discovery of a lump on your precious pooch may prompt you to fear the worst, it’s important to get anything suspicious checked out by a vet before you jump to any conclusions.

If your fears are realised and cancer is the diagnosis, in most cases it can be treated. “Please don’t panic when you hear your dog has a skin cancer. He or she needs you to put on a brave face and do what’s best for them,” Dr T-Malaeb says.

The basic rule when it comes to lumps: “If it is growing rapidly or bleeding it should be checked by a vet.” — Dr Peter Green, Heathmont Animal Hospital.

For more information

Visit for a list of the causes of lumps on or beneath a dog’s skin.

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