Interdigital cysts in dogs form an unsightly lump that may look inflamed or infected. They’re usually easy to spot and tend to only occur on the front paws between a dog’s toes.
Unfortunately, interdigital cysts can be painful for your dog.
They can also be difficult to get rid of and may keep coming back unless the cause is eliminated.
Easier said than done! The most important thing is to make sure a veterinarian has a look. Antibiotics may be necessary if there is any sign of infection.
This post is designed to help you identify the causes of interdigital cysts in dogs. Theoretically, if you can eliminate the cause, you can eliminate the problem.
We’ve also included a video on at-home treatment options towards the end of the post.
What Are Interdigital Cysts in Dogs?
An interdigital cyst is an abscess that forms between the toes of a dog’s front paws.
These sores, also known as interdigital furunculosis, often involve a bacterial infection. This is because the lesions grow in size and eventually rupture.
That rupture leaves the skin open and at risk of bacterial infection.
Dogs can have multiple interdigital cysts between their toes on one or all four paws. If your dog has been excessively licking his or her paws, or isn’t walking normally, have a look at the webbing between your dog’s toes.
Signs of a bumpy sore (they may even be bleeding) are probably interdigital cysts. There can be multiple causes for these cysts as you’ll read later in this post.
How an inflammatory response leads to interdigital cysts in dogs
Interdigital folliculitis describes the initial inflammation that can occur as a response to foreign materials introduced within the deep layers of skin.
It’s thought that ruptured hair follicles beneath the surface of the skin cause enough friction to form a nodule or lump.
When the bumps rupture, hair and keratin from the deep layers of skin are released.
This causes even more irritation and swelling. The lesions grow and rupture, leaving the skin vulnerable to secondary infection.
What do interdigital cysts look like?
You might notice smooth red or purple bumps between your dog’s toes in the beginning.
Eventually, the cyst will rupture and will leak either clear fluid or pus. Sometimes the clear fluid has a red tinge to it.
Why Does My Dog Keep Getting Interdigital Cysts?
Experts are not 100% sure what causes interdigital cysts in dogs. Some dog breeds (detailed further in this post) are more predisposed than others.
Primary conditions can contribute to the problem and underlying conditions can make it worse.
For example, skin allergies may be your dog’s primary condition, but excessive itching or licking between the toes can cause injury to the skin or hair and lead to interdigital cysts.
Other theories on why interdigital cysts developing include the following:
Ingrown hairs
Dogs can develop ingrown hair follicles that can lead to irritation and skin infection.
Hair Coat
Dogs with short bristly hairs are more likely to develop inflamed and ruptured hair follicles.
Shape of the Paw
Dogs with wide paws may put more weight on the haired skin between the pads. This can lead to irritation and the development of interdigital cysts.
Obesity
Overweight dogs naturally put more weight on their paws. This distribution of weight can cause irritation, inflammation, and potentially the development of interdigital cysts.
Underlying conditions
Underlying conditions, like arthritis, may cause a dog to walk improperly. This uneven gait may put more pressure on the interdigital spaces of the dog’s toes, leading to irritation and cysts.
Other underlying conditions can also include autoimmune disorders like hypothyroidism.
Allergies
Allergies can make a dog itch everywhere, including on the paws and in between the toes. They develop red, itchy skin, hair loss, and recurring skin infections as a result.
The most common types of allergies in dogs include:
- Food allergy
- Flea allergies
- Canine atopic dermatitis
Allergies may lead to secondary bacterial infections.
Mites
When diagnosing interdigital cysts in dogs, a skin sample may be taken to rule out demodectic mange from mites, skin cancers, or even fungal infection.
Obesity
Obesity can affect the way a dog walks, placing more pressure on the front paw pads. This excessive pressure on the pads can lead to skin irritation in the webbing of the feet.
Environmental factors
There are many scenarios that could cause trauma to the skin between a dog’s toes. It can happen if your dog has a rough-and-tumble personality who plays on rough surfaces to injuries from a cage or crate.
Preventing Interdigital Cysts in Dogs
There are a few things pet owners can do to help prevent interdigital cysts. Although there’s no guarantee, some basic grooming practices may help.
Dogs may not have another recurrence if the cause is due to a grass awn, or other foreign body. Unfortunately, the condition can recur if the cause is more complicated.
In the case of bacterial infections, there can be several sores (nodules) with new lesions developing just as the other ones are getting better.
Trim Hair
Preventative measures can include trimming the hair in the webbing of your dog’s toes. Be sure to use appropriate scissors, however, because a clipper can cause microtrauma leading to ingrown hair.
Trim Nails
Keep your dog’s nails trimmed so that they don’t break and cause irritation between the toes.
Clean and Wipe
Use a soft wet cloth or baby wipe to clean between your dog’s toes. A veterinarian may recommend washing paws daily with a special shampoo containing 2% chlorhexidine or 2% miconazole.
This will alert you to any foreign object that may be tangled in there and will help wash away irritants like sand, dirt, and grass.
Dog breeds predisposed to interdigital cysts may also benefit from protective footwear.
Are Interdigital Cysts Contagious?
No, interdigital cysts are not contagious.
Dog Breeds Most Susceptible to Interdigital Cysts
Dog breeds thought to be most susceptible to interdigital cysts include the following:
- Labrador retrievers
- Great Danes
- English bulldogs
- German shepherd
- Bull terriers
- French bulldog
- Basset hounds
- Chinese shar-peis
- Doberman pinscher
How Veterinarians Diagnose Interdigital Cysts
Veterinarians can take one look at those red-raised bumps between your dog’s toes and make a tentative diagnosis. In order to make a definitive diagnosis and rule out underlying causes, they’ll also want to do some tests.
Diagnostic tests may include:
Hair Trichograms
The purpose of a trichogram is to exam a sample of hair under a microscope.
It can be used to offer clues as to why your dog has interdigital cysts. For example, microscopic examination of a hair sample can show whether the hair has broken off (due to rubbing or scratching) or whether the hair loss is due to another cause.
This test is also used to detect the presence of Demodex mites or fungal infection.
Impression Smear
Impression smears are used by applying a clean glass slide directly to an open or draining cyst (or wound). They help detect the presence of inflammation, abnormal skin cells, parasites, fungi, bacteria, and cancer cells.
Skin Scraping
Skin scrapings, like impression smears, can be used to reveal bacterial infections, fungal infections, the presence of parasites or cancer.
The procedure is done using a scalpel blade to gently scrape layers of the skin.
Dogs may experience some discomfort during the procedure. However, it’s important for the veterinarian to scrape deeply enough to draw a small amount of blood.
The reason for this is because parasites can live in the deeper layers of skin.
Fine Needle Aspiration
For this procedure, a sterile fine gauge needle is attached to a syringe and inserted directly into the lump. A small amount of tissue fluid (or cells) is collected for microscopic examination.
According to VCA Animal Hospitals, the sample is placed on a clear slide, air-dried by waving it in the air, stained with special dyes, and examined under a microscope.
Skin Biopsy
Skin biopsies can provide insight into whether the interdigital cyst between your dog’s toes pose a serious threat or not.
Some dogs may be given a sedative or general anesthesia. The procedure involves removing the entire cyst or a sample of it. The tissue is then sent to a veterinary pathologist for examination.
Signs Your Dog May Have Interdigital Cysts
It’s not unusual for dogs to groom themselves by licking between their toes. However, if you notice excessive paw licking, there could be trouble brewing.
Many pet owners don’t even realize there’s a problem until there are visual signs. These visual cues can include all or some of the following:
- Raised, red welt between your dog’s toes
- Bumps (hairless) between the toes
- Areas of thick, callus-like skin
- Hair loss between your dog’s toes
- Signs of redness and inflammation
- Open sore that is bleeding
- Sore filled with blood or pus
- Your dog may start walking oddly because of the pain and irritation.
Keep in mind that some sores aren’t visible at all unless the hair is clipped.
Treatment Options
Treatment can be tricky, especially if there are no clues as to an underlying cause. Generally speaking, the three options used for treating interdigital cysts including the following:
Surgery
Surgery removes the affected webbing between the toes. The toes are then sutured for healing. While it can completely remove the cysts, it can also cause orthopedic issues for your dog.
This type of surgery is known as fusion podoplasty.
CO2 Laser
The CO2 laser vaporizes the cysts without affecting the normal tissue. As a result, the procedure doesn’t alter normal paw structure.
Multiple laser therapy applications are sometimes needed depending on the severity of the condition.
Medical Therapy
Medical treatment of interdigital cysts can involve:
- Topical antibiotics
- Oral antibiotics
- Topical steroids (anti-inflammatories)
- Oral anti-inflammatory medication
Some veterinarians prefer cyclosporine because it has fewer side-effects.
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Home Treatment of Interdigital Cysts in Dogs
There are some home treatment options you can try. However, I always recommend seeing a licensed veterinarian before attempting at-home treatment.
The reason is because your dog could be suffering from an undiagnosed underlying condition that needs medical attention.
Things like apple cider vinegar or peroxide can only clean the surface of skin. It cannot penetrate or cure deep bacterial infections.
The following video by Dr. Jones offers tips on how to treat interdigital cysts at home:
Summary
Interdigital cysts are painful for dogs and a challenge for pet owners. If seasonal allergies are the culprit, you may only notice the emergence of these cysts once in a while.
If parasites or infection are the problem, the cysts may appear year-round. Seek veterinary attention if you notice any signs of interdigital cysts in your dog. This includes limping, licking paws excessively, and the appearance of lumps between your dog’s toes.
Works Cited
Clark, Shara. “Interdigital Folliculitis and Furunculosis (‘Interdigital Cysts’) – MedVet.” MedVet, 24 Jan. 2022, www.medvetforpets.com/interdigital-folliculitis-and-furunculosis-interdigital-cysts.
“Treatment Options for Dog’s Foot Sores – Veterinary Medicine at Illinois.” Veterinary Medicine at Illinois, vetmed.illinois.edu/pet-health-columns/interdigital-cysts-removed-by-laser. Accessed 22 Mar. 2023.
Buzby, Dr. Julie. “Interdigital Cyst in Dogs: A Painful Bump Between Your Dog’s Toes.” Dr. Buzby’s ToeGrips for Dogs, 26 Sept. 2022, toegrips.com/interdigital-cyst-dog.
MORIELLO.KAREN. “Interdigital Furunculosis in Dogs – Integumentary System – Merck Veterinary Manual.” Merck Veterinary Manual, www.merckvetmanual.com/integumentary-system/interdigital-furunculosis/interdigital-furunculosis-in-dogs. Accessed 23 Mar. 2023.
“Trichogram.” Trichogram, leicesterskinvet.co.uk/trichogram. Accessed 23 Mar. 2023.