This article was updated on August 14th, 2023
Lumps and bumps on dogs’ legs are a common concern, from itchy insect bites to painless cysts and skin growths. But should you be worried? As a vet I’ll summarize the most common leg issues we see in practice and when it’s worth seeing your veterinarian.
What are the top reasons for leg lumps and bumps in dogs?
From bumpy rashes and hot spots to abscesses secondary to wounds or foreign bodies like grass seeds, infections can cause a range of lumps and bumps on dogs’ legs. Infections typically develop over a few days, causing redness, itching, pain and often pus. Saltwater bathing may help but significant infection is likely to require veterinary treatment. Abscesses shouldn’t be ignored as foreign bodies like grass seeds can migrate, causing further problems. Learn more about skin infections in dogs.
2. Insect bites and stings
These are common in the warmer months, causing localised swelling, itching and redness. If you notice any systemic signs or the swelling is severe, you should see a vet who can prescribe medication including antihistamines or steroids if needed.
Occasionally, dogs can develop hives – itchy, raised welts across areas of their skin – in response to allergens. These are usually transient, though if your dog is suffering a severe reaction – for example, they have breathing difficulties or substantial swelling – they should see a vet urgently. Learn more about dog skin allergy issues and rashes.
Cysts are a common cause of lumps on the body and legs. These benign lumps develop from glands in or just under the skin and gradually fill with fluid or thick greasy material. Their appearance depends on their specific type ranging from smooth lumps just under the skin to irregular small lumps on the skin surface. They may cause inflammation if they rupture but otherwise don’t need treatment; surgery is usually curative if needed. Learn more about cysts on a dog’s paws.
5. Warts and tumors
Benign tumors like sebaceous adenomas (‘old dog warts’) are very common in older dogs, while virus-induced warts are common in young dogs and usually resolve over a few months. Pictured below are examples of warts on a dog’s leg:
Benign tumors have a variable appearance but are usually small, slow-growing and not inflamed. Unfortunately, malignant tumors like mast cell tumors are not uncommon on the legs; these often grow rapidly and cause irritation but can appear benign.
It’s important to discuss testing of any new lump with your vet to rule this out. View pictures of lumps and bumps.
6. Calluses and hygromas
Larger dogs with less padding (like Greyhounds) or those that frequently lie on hard surfaces may develop thickened calluses over areas like the elbow due to pressure. In some cases, dogs can also develop a benign soft, fluid filled, cyst-like ‘hygroma’ over pressure points like the elbow. The treatment is thick bedding and preventing lying on hard surfaces, but it’s worth seeing your vet if it doesn’t respond over a few weeks.
7. Lick granulomas
Lick granulomas are a chronic inflammatory response to irritation – they often begin after a mild insult like an allergic reaction, sting or graze but a vicious cycle develops whereby the dog’s licking causes further irritation and itching. Treatment can be difficult and includes medication and preventing licking.
Signs that you need to see your veterinarian
Signs you should see your vet include:
- Any lump that persists for more than a few weeks
- Any lump causing soreness, itching or pain
- Any rapidly growing or spreading lump or bump
- Any lump associated with systemic signs e.g. breathing difficulties
What will happen at the vet
Your vet may need to do further investigations like a fine needle aspirate ($150-200) in order to make a diagnosis. Depending on the diagnosis treatment may include monitoring, medication or surgery.