Interdigital Cysts in Dogs
Interdigital cysts, also known as podo furunculosis, follicular pododermatitis, or interdigital furuncles, refer to small or large lumps in the webbing between the dog’s toes. The cyst may be filled with pus or blood. One or more nodules may be present and they are usually found in the dog’s front paws.
Causes of Interdigital Cysts in Dogs
Injury or irritation of the hair follicles in the paw cause them to dilate and get filled with keratinocytes that shed from the follicular epithelium. These nodules can rupture, making the exposed skin susceptible to more irritation and eventually, infection.
Interdigital cysts in dogs, especially recurring ones, can be caused by a variety of factors, which include:
The dog’s genetic material determines its physical appearance and therefore, serves as a predisposing factor to the development of interdigital cysts. For instance, breeds with bigger and wider paws are more likely to suffer from this condition. The reason for this is that the haired part of the paws are more likely to bear the dogs’ weight when they’re walking, making it prone to irritation or injury. Breeds of this configuration include Labrador Retrievers, Pekingese, German Shepherds, and English Bulldogs.
Additionally, dog breeds with short and coarse hair coats like Great Danes, Mastiffs, Boxers, Bull Terriers, and Bassett Terriers are also predisposed to developing this condition. These breeds’ hair follicles are more prone to get irritated and inflamed.
Obese dogs tend to put more pressure on the spaces between their toes when walking compared to dogs with normal weight.
The source of skin trauma can be from the dog’s cage or play area. Pet owners should be mindful of the ground or surfaces that the dog walks on. Also, an unsanitary condition will exacerbate the problem as well.
Other Underlying Medical Conditions
Other underlying conditions like arthritis or hip problems can cause interdigital cysts in dogs. Dogs with these health problems will have an abnormal gait, which oftentimes results in more pressure in the interdigital space.
Likewise, any condition that could cause the dog to chew or lick their paw could lead to irritation of the hair follicles. For instance, dogs suffering from an allergy are predisposed to developing interdigital cysts.
Since many skin conditions can also cause nodules to form, the veterinarian will employ several diagnostic procedures to rule out other conditions. To obtain a definite diagnosis, the vet will initially perform a thorough physical exam. The dorsal and ventral parts of the paws are checked for other growths and comedones if present. The vet may attempt to express the contents of the nodules if possible.
Aside from the physical exam, the veterinarian may also request the following tests:
Skin Scraping or Impression Smears. Skin scrapes or hair plucks are obtained and analyzed under the microscope to rule out demodicosis. Also, impression smears on adhesive slides help check for yeast infection.
Intradermal Skin Test. This test is done to assess if the dog has atopic dermatitis, a hereditary predisposition to the development of allergic symptoms.
Hematology. A complete blood test, biochemical profile, and even urinalysis are required especially with unresponsive cases.
Cytology. This is performed to check for evidence of other causes of the interdigital cysts. For instance, eosinophilic inflammation is indicative of skin diseases like sarcoptic mange. Infectious agents and foreign material could also be detected with this test.
Bacterial Culture and Antimicrobial Susceptibility Test. This may be necessary even though Staphylococci have become the most prevalent cause of infection to assess which antibiotic therapy is the most effective treatment. If two bacterial culture turns out negative, sterile pyogranuloma syndrome is suspected.
Biopsy. Tissues are taken from the draining area and even the bottom of the dog’s feet. This is used to confirm if the abscesses are true follicular cysts.
Depending on the severity of the condition, the veterinarian may employ one or a combination of these treatment options:
This is indicated for patients suffering from an infection. The vet may prescribe an oral antibiotic or an anti-bacterial shampoo to treat the infection. Additionally, if the dog is suffering from sterile pyogranuloma or allergy, glucocorticoids may also be prescribed.
CO2 Laser Ablation
This surgical procedure is done especially in recurring cases. A CO2 laser is used to remove the affected follicles without causing any damage to the adjacent tissues. CO2 laser ablation is the treatment of choice because approximately 90% of the patients that underwent this procedure were a success.
In severe cases, this procedure may also be considered to remove the cysts and prevent a recurrence. To perform this, the affected interdigital skin is excised using a scalpel. The adjacent digits and pads are then fused by suturing them. For this surgery to be successful, underlying conditions must be identified and controlled before the procedure. Also, pet owners should note that although this may remove the cysts, pain and the habit of foot licking may persist.
If there is an underlying cause (arthritis or obesity, for instance), treatment should also address this to prevent the recurrence of the problem in other parts of the paws.
Cost to Treat
Depending on the course of treatment and your pet’s health, the cost to treat an interdigital cyst can range anywhere between $200 to $1,000.
Aftercare and Management
The veterinarian will work with the pet owners and provide a list of instructions upon the dog’s discharge. The instruction will cover prescribed medications, doses, and schedules. If the dog is overweight, the vet may also modify the pet’s diet. It’s the pet owner’s responsibility to follow through with the instruction and schedule a future appointment with the clinic.
Additionally, if the dog went through surgery, it may have to use an Elizabethan collar to prevent self-injury and to facilitate faster recovery. Postsurgical care of the wound like the application of ointment and change of bandage must also be strictly followed.
It’s hard for pet owners to see their dog wincing in pain while walking. Fortunately, interdigital cysts in dogs is a very treatable condition. However, the way to recovery can be quite lengthy and pet owners have vital roles to play in that process.