Interdigital cysts are inflamed areas that form between your dog’s toes. They’re often mistakenly called cysts, but they actually stem from problems with the hair follicles on your dog’s paws and can be a sign of a dog developing interdigital cysts. These bumps can cause your dog quite a bit of pain and discomfort and you might notice your dog limping which is more noticeable when your dog walks on uneven or rocky surfaces. Continue reading to learn more about interdigital cysts in dogs and how you can help.

What are interdigital cysts in dogs?

Interdigital cysts in dogs, also known as interdigital furuncles, interdigital furunculosis, or follicular pododermatitis, are not true cysts but are sometimes painful cysts that are inflamed lesions commonly found between a dog's toes in the interdigital spaces of the dog’s feet.

They often look like small, red, and inflamed areas, and they can be filled with fluid or pus. These cysts in dogs are most commonly found on the front paws, in the interdigital spaces between toes 3 and 4, or toes 4 and 5.

Despite their name, interdigital cysts aren’t true cysts. They are actually a type of skin inflammation and sometimes skin infection, called follicular cysts. These lesions developing are caused by problems with the hair follicles in your dog’s paws. When these follicles get damaged or irritated, they can become inflamed and form these painful bumps.

What causes dogs to develop interdigital cysts?

Identifying the underlying cause of interdigital cysts in dogs is important for effective treatment and prevention. These painful lesions often arise from a combination of factors that trigger inflammation and infection within the paw.

Here are some of the common causes:

  1. Damaged hair follicles: Healthy hair follicles are essential for maintaining skin integrity. However, factors such as trauma, excessive licking, or even breed-specific conformation can damage these follicles, leading to inflammation and the formation of interdigital cysts. Ruptured hair follicles can exacerbate the condition, allowing for secondary infections to develop.
  2. Foreign body reactions: Foreign material, such as grass awns or small pebbles, can become embedded in the interdigital spaces. This triggers a foreign body reaction, as the dog’s immune system attempts to expel the foreign material. The resulting inflammation can contribute to the development of interdigital cysts.
  3. Infections: The interdigital spaces provide an ideal environment for bacterial and fungal growth. Bacterial infections, often leading to recurrent skin infections, are a common culprit in the formation of interdigital cysts. Additionally, fungal infections and infestations with demodex mites can also contribute to the problem.
  4. Allergies: Allergies play a significant role in the development of interdigital cysts. Canine atopic dermatitis, environmental allergies, and food allergies can all trigger inflammation and pruritus (itching) in the paws. As dogs lick and chew at their itchy paws, they can damage hair follicles and create an entry point for bacteria, leading to cyst formation. Allergic skin disease can further complicate the diagnosis and treatment of these lesions.
  5. Other contributing factors: While the above factors are common triggers, other conditions can also contribute to the development of interdigital cysts. These include follicular cysts, obesity, and breed predispositions. Certain breeds, such as Labrador Retrievers, Pekingese, Bulldog and Mastiff breeds, are more prone to developing interdigital cysts due to their skin type and paw conformation.

By knowing what the underlying culprit is, we can work towards an effective treatment strategy. Identifying and managing any underlying disease is crucial for preventing the recurrence of interdigital cysts.

What are the symptoms of interdigital cysts in dogs?

Interdigital cysts in a dog's paws can manifest through various symptoms, which may vary in intensity depending on the severity of the condition.

Interdigital cyst in dogs. Photo shows a cyst on the paw
Notice the large swelling between the toes, on the paw in this dog. This is an interdigital cyst
Interdigital cyst in a dog. Photo shows a cyst on the paw
  • Visible lumps or nodules: The most obvious sign of interdigital cysts is the presence of visible lumps or nodules between your dog’s toes. These lesions are often red, and swollen, and may be filled with fluid or pus. They are most commonly found on the front paws, but can sometimes occur on the hind paws as well.
  • Limping or lameness: Dogs with interdigital cysts often limp or show signs of lameness due to the discomfort and pain caused by the cysts, especially when walking on rough surfaces.
  • Discharge: In some cases, the cysts may rupture, leading to the presence of fluid or pus, which can be a sign of a secondary infection.
  • Excessive licking or chewing: Excessive paw licking attempts to alleviate the itchiness and discomfort associated with the cysts, which can further damage hair follicles and exacerbate the condition. This also contributes to chronic inflammation of the interdigital spaces.
  • Pain and sensitivity: The area around the cysts may be sensitive to touch, causing the dog to react when the affected paw is handled.
  • Changes in behavior: Due to the pain and discomfort, dogs may exhibit changes in behavior, such as increased irritability or reluctance to engage in usual activities.

If you notice that your dog has any of the above symptoms, please see your veterinarian to review diagnostic and treatment options.

How will your veterinarian diagnose an interdigital cyst with a skin biopsy?

Your veterinarian diagnoses interdigital cysts through a step-by-step process to get to the root of the problem and make sure we’re not dealing with something else entirely.

Your vet will start with a clinical exam, giving your dog’s paws a thorough once-over while also checking out their overall health. This helps them get a handle on what’s going on and spot any red flags that might be contributing to the issue.

To dig deeper, your vet might do a skin scraping. This is a simple test to check for tiny parasites like demodex mites or signs of fungal infections. If there’s a whiff of a bacterial infection, a bacterial culture will help pinpoint the exact bacteria involved, making it easier to choose the right antibiotics for the job.

Depending on what they find, your vet might suggest some extra tests. These could include allergy tests to spot any pesky allergens causing the paw problems, blood tests to ensure everything else is running smoothly, or even imaging tests to get a better look at the affected areas.

For those stubborn, recurring cysts where the cause remains a bit of a mystery, a skin biopsy might be the next step and this would allow for a more definitive diagnosis.

Treatment options for interdigital cysts in dogs

When it comes to treating interdigital cysts in dogs, the primary goal is to address the underlying cause. This ensures long-term relief and reduces the chance of recurrence. Interdigital cysts treated by veterinarians often involve a combination of therapies to manage symptoms and prevent future occurrences.

Your veterinarian will develop a treatment plan geared to your dog’s specific needs, which may include the following:

  • Topical therapy: Medicated shampoos, wipes, and ointments can help manage skin infections, reduce inflammation, and promote healing. Topical treatment is often used in conjunction with other therapies to treat interdigital cysts comprehensively.
  • Anti-inflammatory medications: Reducing inflammation is crucial for managing pain and discomfort. Your veterinarian may prescribe anti-inflammatory medications, such as systemic glucocorticoids (e.g. prednisone for dogs), to help alleviate symptoms and promote healing.
  • Antibiotics and antifungals: If a secondary bacterial infection or fungal infection is present, your veterinarian will prescribe appropriate antibiotics or antifungals to combat the infection. It’s important to complete the full course of medication, even if the interdigital cysts seem to be improving.
  • Epsom salt soaks: Soaking the affected paw in warm water with Epsom salts can help soothe the inflammation and draw out infection. This can be a helpful addition to other treatments, providing relief and promoting healing.
  • Laser surgery: In some cases, laser surgery may be recommended to remove infected tissue or scar tissue. This can help reduce inflammation and promote healing.
  • Surgery (Fusion Podoplasty): For severe cases or chronic recurrent lesions that don’t respond to other treatments, a surgical procedure called fusion podoplasty may be considered. This involves removing the affected tissue and closing the interdigital space to prevent recurrence.
  • Natural treatments: Some pet owners may explore natural treatments, such as essential oils, or omega fatty acids under the guidance of their veterinarian.

How to prevent interdigital cysts in dogs

Preventing interdigital cysts in dogs involves a combination of good hygiene, regular grooming, and proactive care. Here are some tips to help dog owners minimize the risk of these painful lesions developing:

  • Maintain good hygiene: Keep your dog's paws clean and dry, especially after walks or outdoor play. Washing your dog's feet with a mild dog shampoo and thoroughly drying them can help prevent bacterial and fungal infections.
  • Grooming and trimming: Regularly trim the hair between your dog's toes to reduce the risk of ingrown hairs and damage to hair follicles. Grooming also helps in spotting any early signs of skin conditions or inflammation.
  • Manage allergies: If your dog is prone to allergies, work with your veterinarian to identify and manage any allergic reactions. This may include dietary changes, allergy medications, or topical treatments to reduce inflammation and itching.
  • Weight management: Maintain a healthy weight for your dog to reduce stress on their paws. Obesity can exacerbate paw problems and contribute to the development of interdigital cysts.
  • Provide a balanced diet: Ensure your dog receives a balanced diet rich in essential nutrients to support skin health. Omega fatty acids, in particular, can help reduce inflammation and promote healthy skin.
  • Avoid rough surfaces: Limit your dog's exposure to rough or rocky surfaces that can cause trauma to their paws. Consider using protective booties during walks to provide extra protection.
  • Address excessive licking: If your dog is prone to excessive paw licking, identify and address the underlying cause, such as allergies or boredom. Providing mental stimulation and interactive toys can help reduce stress-induced licking.

Interdigital cysts in dogs can be a painful and frustrating problem for both pets and their owners. However, by understanding the causes, recognizing the symptoms, and seeking prompt veterinary care, you can help your dog find relief and prevent future occurrences. Because they can have various underlying causes, your veterinarian can make the diagnosis of interdigital cysts by using a combination of diagnostic tools. Remember that successful management often hinges on identifying and addressing the underlying cause, whether it's allergies, foreign bodies, infections, or other contributing factors.