8 Types of Bumps, Blisters or Sores on Dog’s Toes [Pictures]

This article was updated on September 6th, 2023

As veterinarians, we often diagnose dogs with lumps, bumps, blisters, or sores on their toes. In some cases, the appearance of the lump can indicate the likely cause and treatment. In other cases, diagnostic tests are needed. In this article, we’ll review common diagnoses, including interdigital cysts, foreign bodies like grass seeds, and growths such as papillomas, corns, and tumors. Let’s take a look!

Top causes of new lumps and bumps on toes

1. Infections and foreign bodies

Dogs can develop swollen lumps, bumps, or blisters on their toes due to infections or foreign objects like grass seeds, which are common in summer. These lumps usually appear between the toes but can occur further up the foot or leg. They are typically swollen, painful, red, and inflamed and can worsen over time, often with pus draining from them. Your dog may become lame due to the pain.

To prevent the inflammation from worsening, it’s important to use a buster collar to prevent your dog from licking or chewing the affected toes. Bathing the affected toes in warm water with Epsom salts for 10-15 minutes several times a day (then drying thoroughly) may relieve pain. However, it won’t resolve the issue.

Prevention is key, so in the summer, it’s worth checking your dog’s toes after walks and removing any grass seeds, especially if your dog has long or curly hair between their toes (e.g. spaniels).

To resolve these lumps or sores, veterinary treatment is usually necessary. Leaving an infection or foreign body can make it worse and increase the likelihood of complications. If foreign material is present, your vet can sometimes remove it with local anesthetic, but more thorough surgical exploration under sedation or general anesthetic may be necessary. Your vet will likely also prescribe antibiotics and pain relief, as well as a collar to prevent excessive licking.

With appropriate treatment your dog should recover quickly. In rare cases, foreign material can be difficult to locate surgically and further imaging may be required. It’s important to follow your vet’s advice and attend any follow-up appointments to ensure your dog fully recovers.

2. Interdigital cysts

Interdigital cysts, also known as interdigital furunculosis, are typically small, firm bumps between the toes, usually on the front feet. They are usually red and inflamed, sometimes oozing discharge or pus. If severe, they may cause lameness. It can be difficult to differentiate these from infected foreign bodies like grass seeds between the toes.

You can also view more pictures of intergital cysts here and here. Various factors, such as allergies, infections, conformation, abnormal weight bearing, and short bristly hairs between the toes (e.g. bulldogs, Labrador Retrievers), can contribute to the development of interdigital cysts.

Home treatments include bathing with Epsom salts as described above. This is unlikely to fully resolve the cyst, however, and veterinary treatment is recommended due to the possibility of foreign bodies or other underlying causes. Using a buster collar is also recommended to prevent your dog from licking the area, which can worsen inflammation and introduce infection.

Often, your vet will be able to diagnose an interdigital cyst based on physical examination. They may recommend further tests such as skin scrapes or hair plucks to look for bacteria and mites. In some cases, surgical exploration is necessary to rule out a foreign body.

Treatments depend on the specific causes identified in your dog’s case and may include antibiotics, bathing, anti-inflammatory medication, and management of any underlying allergies. In rare cases, surgery may be needed. The prognosis is generally good with appropriate treatment.

3. Corns (keratomas)

Corns are usually hard, thickened, raised circular areas on the weight-bearing areas of the pads. They are painful, particularly on hard surfaces. You can view a picture of a keratoma on the KingsDale website here or on the AZGreyhounds website here.

Dogs can develop painful corns on their pads due to abnormal pressure or trauma to the pads from abnormal weight-bearing (e.g., due to arthritis) or rough surfaces. This causes a benign (i.e., non-cancerous) overgrowth of the keratin-producing cells in the pad. Sighthounds like greyhounds are particularly likely to be affected.

Home treatments are limited, although avoiding hard or rough surfaces will help to reduce pain. Corns are usually slowly progressive so we recommend seeking veterinary treatment. Diagnosis is often based on physical examination, but further investigations like x-rays or a biopsy may be recommended to rule out underlying conditions like arthritis or a tumor. Treatment usually involves pain relief and surgical excision. Occasionally, ointments may be useful to soften the corn. Prognosis is variable, as recurrence after surgery is relatively common.

4. Papillomas

Papillomas, also known as warts, are common in dogs. They are caused by a papillomavirus and, in many cases, resolve on their own over months to years. Papillomas usually appear as small raised lumps, which commonly have an irregular, bumpy surface and can be pink, tan, or the same color as the surrounding skin.

Young dogs are most commonly affected and can have multiple papillomas across the body, especially the face, mouth, and neck.

Papillomas are not typically itchy or painful but, in some cases, can become infected or rarely develop into other types of tumors. If a papilloma is causing irritation, it should be checked by your vet. Papillomas do not typically require treatment, but if they are causing irritation, surgical removal or a biopsy to rule out malignant tumors may be recommended. It is important to regularly check any papillomas for changes, growth, or irritation.

5. Lick granulomas

Also known as acral lick dermatitis, lick granulomas occur in dogs as a result of excessive licking. The licking may be due to conditions like allergies, joint pain, or anxiety. They typically occur over the ‘wrist’ (carpus) but can occur on legs and paws.

Other helpful pictures can be found here: 1, and 2.

This is not a rare condition and typically causes focal thickened areas of skin, often with hair loss, rather than a well-defined lump. There may be inflammation.

Diagnosis is often based on a physical examination but investigations like x-rays or biopsies may be recommended to rule out conditions like joint disease or a tumor. Treatment involved addressing the underlying issue, preventing licking using a buster collar or other deterrents, and medication to reduce itching. 

Many dogs recover well from lick granulomas, although the prognosis is variable depending on the cause and severity of the problem. If lick granulomas are left, they may become more severe and difficult to resolve.

6. Histiocytomas

Histiocytomas are benign skin tumors that are relatively common in younger dogs. They are typically small (< 2cm), round, raised, and reddish-pink; they may appear inflamed, but they do not usually cause pain or irritation. Histiocytomas are more common on the head, neck, and ears but can occur on toes. 

These masses usually regress spontaneously in weeks to months and do not require specific treatments. The area should be kept clean and dry, as secondary infection is possible if the histiocytoma is traumatized.

If you notice a rapidly developing or inflamed lump, it’s important to consult your vet to rule out a malignant tumor. Histiocytomas can mimic the appearance of a more aggressive tumor (e.g. a mast cell tumor) so your vet may recommend testing to rule this out. View more pictures of histiocytomas.

7. Nail related lumps

Nail-related lumps in dogs are not very common but when they do occur, they should be evaluated by your vet. Many benign lumps can develop around the base of a nail, and infections may also occur due to trauma or a split nail. However, some cancerous tumors are more likely in this area, including squamous cell carcinomas and melanomas (see below). Early detection and treatment can be crucial for a better outcome.

8. Malignant tumors

Lumps that develop rapidly or cause irritation are more concerning. Monitoring these for an extended period at home is not recommended as most malignant skin tumors require surgery, and early diagnosis increases the likelihood of successful treatment. 

The prognosis for these tumors is very variable depending on the type, size, whether the tumor has spread (metastasis), and what treatment is chosen. If the tumor is removed completely and there is no metastasis, the prognosis can be good.

If your dog has a sore lump on their toes, you can help by gently bathing the area with warm water and keeping it clean and dry. Using a buster collar to prevent any licking or chewing is also recommended.

Some of the more common tumors seen include:

a) Mast cell tumors

These tumors can appear anywhere on the skin, including the paws and toes. They may be small and well-defined or larger and more irregular. They often cause irritation, and your dog may chew or lick at the lump. Early diagnosis and treatment are critical as these can be very aggressive, even if small.

View another picture here from University of California’s UC Davis.

b) Squamous cell carcinomas

Or view this picture from VeterianKey.com (squamous cell carcinomas between the toes).

These are malignant tumors that develop from skin cells. They can develop anywhere but lumps on the toes are particularly concerning as they make up nearly 50% of malignant tumors in this region. They usually develop in middle-aged to older dogs and appear as a raised, firm, crusty, or scaly area, which can be pink or brown and may ulcerate or bleed as it grows larger; however, this is variable, and smaller tumors may appear as a nodule. They are often very infiltrative, so aggressive surgical treatment is usually recommended.

c) Melanomas

Melanomas can occur anywhere in the skin and are the second most common tumor associated with the toes in dogs. Breeds, including Schnauzers, Irish Setters, Golden Retrievers, Rottweilers, Poodles and Labrador Retrievers are at higher risk, but regardless of breed, black-coated dogs are more likely to develop melanoma. 

Melanomas often appear darkly pigmented but can be less pigmented. They are often irregularly shaped but can be any size and raised or flat. Some appear similar to warts or other benign lumps. 

Early diagnosis is essential as melanomas that occur on the toes are usually much more aggressive than those affecting other areas. There is a high risk of spread to other tissues and they may damage underlying bone, causing pain and lameness. If this type of tumor is diagnosed, your vet will often recommend investigations to rule out spread to other organs. Treatment usually involves amputation of the affected toe but may also include radiotherapy and immunotherapy.

Signs that it is ok to wait-&-see

In almost all cases, a new or changing lump on your dog’s toes should be checked by your vet. Many of these lumps are treatable but require veterinary attention (e.g. foreign bodies, infections, interdigital cysts etc.) and may progress and cause pain and complications if left untreated. Lumps like warts and histiocytomas do not require any treatment, but some malignant tumors may be mistaken for these benign lumps. Delayed diagnosis and treatment of a malignant tumor can have serious consequences for your dog’s health and prognosis.

Signs that you should see your vet 

If you know a foreign body like a grass seed has become trapped under your dog’s skin and is causing irritation, rapid removal may prevent significant infection from developing.

If a lump is ulcerated, bleeding, or causing significant irritation, it should be assessed as soon as possible.

Could your dog’s bump on the toes be cancerous?

Not all cancerous lumps are obvious. Some signs that a lump may be cancerous include:

• Rapid growth
• Pain (potentially causing lameness)
• Irritation (causing licking and chewing)
• Ulceration of the skin
• Changes to nail growth or lost nails

Other factors that increase the likelihood of a cancerous lump include old age and certain breed predispositions (e.g. Boxers commonly develop mast cell tumors).

Cost of diagnosing a bump at the vet

We diagnose many foot-related lumps based on history and physical examination – lumps caused by infection or foreign bodies are often easily recognized and treatment initiated. In some cases, for example, if a more severe infection is suspected, swabs or skin scrapes may be performed to look for specific bacteria or parasites. This may cost around $50 to $200, depending on the tests being performed.

For lumps where a tumor may be suspected, a sample of cells is often obtained via ‘fine needle aspirate’ using a small needle and syringe. These cells can then be assessed under the microscope, either by your vet or a laboratory. This commonly costs around $200.

In some cases, a larger biopsy is needed. A punch biopsy may be performed, either under local anesthetic or sedation. This usually costs around $400-$800, depending on the anesthesia required.

Can a vet diagnose a bump through a video call (instead of an in-office appointment)?

If you are able to take high-quality, clear photos or video of a lump, your vet may be able to give a reasonable idea of the likely cause via video call. It can be helpful to use an object like a ruler or coin for scale if taking close-up photos. For a definitive diagnosis, however, further tests will be needed.

In many cases, your vet will need to see your dogin person. Lumps on feet can be very difficult to photograph and they may also need to feel the lump, perform a full physical examination to rule out other issues, and perform further investigations like a fine needle aspirate or biopsy.

References:

Grassinger, J. M., Floren, A., Müller, T., Cerezo-Echevarria, A., Beitzinger, C., Conrad, D., Törner, K., Staudacher, M., & Aupperle-Lellbach, H. (2021). Digital Lesions in Dogs: A Statistical Breed Analysis of 2912 Cases. Veterinary sciences, 8(7), 136. https://doi.org/10.3390/vetsci8070136