Yeast infection involving dog paws is a type of pododermatitis (podo = foot, derm = skin, itis = inflammation). There are many different types and causes of pododermatitis; we will focus on yeast infections or yeast dermatitis in this article. Yeast dermatitis can affect any breed, but bulldogs, West Highland terriers, poodles, basset hounds, pugs, chihuahuas, dachshunds, and lhasa apsos are more likely to be affected, either due to genetics or folds of skin providing the perfect environment for yeast. This article discusses the symptoms, causes, diagnosis, treatment, and prevention of yeast dermatitis.
Yeast Infection in Dog Paws – Symptoms
The most common clinical signs of yeast dermatitis are itching and redness, a musty odor, and possibly a greasy film over the areas of redness. Since the paws are very itchy, dogs will lick at them in an attempt to relieve the itch, causing fur loss in the area of the infection, as well as brown salivary staining of the remaining fur in the area. The nail beds may also be inflamed, and the nails themselves may take on a brown color. Hyperpigmentation of the skin (darkly pigmented skin) may also be seen in chronic cases.
Yeast dermatitis is caused by the fungus Malassezia pachydermatis. Yeast are single-celled organisms with a nucleus and a cell wall that prefer to inhabit a dark and moist environment. Thus, ear canals, skin folds, and between the toes and paw pads of the feet tend to be where yeast infections occur.
Your dog’s skin is normally host to a number of bacteria and yeast. Under normal circumstances, this is not an issue because your dog’s immune system keeps the bacteria and yeast populations from getting out of control. However, if the conditions of your dog’s skin changes, or if your dog’s immune system is suppressed, these fungi can take advantage of the situation and cause an infection. A yeast infection is most commonly seen as a secondary effect of an allergic dermatitis (environmental allergy, food allergy, flea bite sensitivity), as a result of the skin conditions changing. Less likely, but still possible, is seeing yeast infections associated with some endocrine diseases, especially hypothyroidism.
Yeast Infection in Dogs Paws – Pictures
Diagnosis – Yeast Infection in Dog Paws
There are several different methods that can be used to identify the organism that is causing the infection. All involve collecting a sample of the organism from the skin and looking at the sample under a microscope. Yeast are large compared to bacteria and are often in the process of reproducing, also known as budding, so they appear as a round shape with a smaller round shape (the new yeast cell) attached to it.
Skin scraping – For this test, a scalpel blade is dulled and coated with mineral oil. Using the edge of the scalpel blade, the veterinarian will hold the affected skin taut and gently scrape off the top layer of skin. The skin cells (and hopefully the causative organisms) are then spread on a microscope slide with more mineral oil and examined under a microscope. This method is particularly useful in ruling out the mites that cause scabies and mange.
Impression smear – This test works best with infected areas that are moist and easily accessible. A microscope slide is pressed against the skin of the affected area and then examined under a microscope.
Cotton swab sample – This method uses a moistened cotton swab to collect organisms on the surface of the skin, and works well in between toes and other places it’s difficult to make an impression smear. The cotton swab is then rolled onto a microscope slide and examined.
Acetate tape – A piece of clear tape is applied to the skin, sticky side against the skin. The tape is then applied to a microscope slide and examined. This method works best with drier skin irritation.
Skin biopsy – This is the most invasive test since it involves what is called a punch biopsy. Local anesthesia is used at a minimum; some patients require sedation or general anesthesia for the procedure, depending on patient temperament and location of the biopsy site. A full-thickness layer of skin is removed using a punch instrument and scissors, and the resulting wound is closed with one or two sutures. The biopsy sample is then sent to an outside laboratory for histopathology analysis. While the most invasive, it is also the most accurate for getting a full picture of what is happening with the skin when the more common and less invasive diagnostic tests fail to establish a diagnosis.
Treatment of yeast infections can be oral, topical, or some combination of both, depending on the severity of the infection. Oftentimes, topical treatment is sufficient for mild to moderate cases that are not chronic in nature.
Topical treatments include medicated shampoos, wipes, sprays, creams, or lotions. When using medicated shampoos, dogs that have particularly greasy or oily skin would benefit from a degreasing shampoo containing selenium sulfide or benzoyl peroxide first. An anti-fungal shampoo containing miconazole or ketoconazole in combination with chlorhexidine such as [KetoChlor], [MiconaHex+Triz], or [Malaseb] would follow. In order for the anti-fungal shampoo to be effective, it must remain in contact with the skin for at least ten minutes before being rinsed away. Shampooing of the affected area should occur every 3-5 days for two to twelve weeks.
Medicated wipes, sprays, creams, or lotions such as [Mal-A-Ket] wipes, Animax ointment, or Tresaderm solution may be prescribed instead of the medicated shampoos; these products are usually applied every 12-24 hours for several weeks.
Oral treatments are used in cases where the dermatitis is more severe, persistent, or chronic. Oral antifungal medications such as ketoconazole and fluconazole are available, and are usually administered for several months. However, they do have side effects, particularly potential liver damage, so blood work should be monitored while your dog is on the oral antifungal medication.
Many dogs with yeast dermatitis will also have a concurrent bacterial infection, so oral antibiotics may be prescribed for several weeks to help clear up the bacterial infection.
For uncomplicated yeast dermatitis, the prognosis is generally good and your dog will start feeling less itchy within a week of starting treatment. In dogs with underlying allergies or a compromised immune system, treatment and prognosis is more dependent on the underlying causes and the ability to control those conditions.
As mentioned above, yeast pododermatitis is often secondary to environmental, food, or flea allergies, and therefore, yeast dermatitis will tend to recur unless the underlying cause is addressed. Your veterinarian will work with you and your dog to determine what the underlying cause might be and determine the best treatment. Some diagnostics and treatments your veterinarian might recommend include:
Environmental allergies – The most common environmental allergens are dust mites and pollen. Dust mites inside the house can theoretically be controlled by frequent and thorough cleaning and vacuuming of the house and washing of the dog bedding. There are also several products on the market that claim to reduce dust mites and their allergens, but only [Acarosan] has some scientific evidence to back up the claim.
There are a few treatment options available for environmental allergies. One possibility is to have allergy testing done to determine the exact trigger(s) for your dog’s allergies. This can be a skin test or a blood test. Using the information from the test, an immunotherapy treatment specific to your dog’s allergies can be prepared. The immunotherapy is then administered to your dog at home on a set schedule either via an injection or under the tongue. A drawback to immunotherapy is that it doesn’t work immediately to relieve symptoms and it doesn’t work for every dog. While the immunotherapy is taking effect, your veterinarian will prescribe other, short-acting drugs to help relieve your dog’s symptoms, but within 12 months, 50% of dogs using immunotherapy will have an improvement in clinical signs, while 80% will be able to have their anti-inflammatory and anti-itch medications reduced.
Drugs that are used to get control of environmental allergies include oral or topical steroids, Apoquel, or Cytopoint. Steroids (prednisone, prednisolone, Temaril-P) have long been used for their anti-inflammatory properties, but Apoquel and Cytopoint are relatively new on the scene. Both Apoquel and Cytopoint act on some part of the “itch pathway” at the cellular level, albeit by different mechanisms. Apoquel is a daily oral medication, while Cytopoint is an injection administered monthly. Steroids, Apoquel, and Cytopoint can also be used in long-term management of environmental allergies, as well as another drug called Atopica (cyclosporine). Atopica is an oral medication that modulates the immune system and can be quite effective in helping to relieve environmental allergies, but it takes 8 weeks for it to reach full effectiveness, so other medications are given concurrently at the start of therapy in order to immediately relieve the itchiness.
Food allergies – Some dogs are allergic to a particular protein. If this is suspected, your veterinarian will guide you through the process of a food trial. Your dog will be fed a “novel protein” diet – one that has a meat protein your dog has not yet eaten – such as rabbit, duck, or venison, for at least six weeks. In addition to the diet change, your dog will be given medications to treat the dermatitis. Once the symptoms are relieved, the medications will be stopped and your dog will continue on the new diet. If the itchiness and infection don’t recur, then a food allergy was likely the underlying cause. Ideally, to confirm the diagnosis, your dog would return to his old diet, and if the symptoms recur within 14 days of restarting the old diet, then an allergy to a protein in his old diet can be confirmed and a diet with the new protein should be resumed.
Flea allergies – Treatment of the fleas with [Capstar] and monthly flea and tick preventative should resolve the underlying cause fairly quickly, and dogs should be placed on a monthly flea and tick preventative year-round.
While fairly rare, some endocrine system disorders can cause yeast infections to be more likely to develop. The most common is hypothyroidism, a condition where not enough thyroid hormone is produced. Thyroid hormone levels affect many different things including appetite, weight, energy level, and haircoat; dogs with hypothyroidism will often have a decreased appetite, increased weight, decreased energy level, and a thinning haircoat. Thyroid levels are tested via a blood sample sent to an outside laboratory, and hypothyroidism is easily treated with thyroid hormone (levothyroxine) supplementation.
Take-away message for yeast dermatitis
Yeast dermatitis is usually caused by another condition, particularly allergic dermatitis. Environmental or food allergies are the most likely underlying causes, and those conditions should be identified and treated in order to help prevent recurrence of the yeast infection. Every dog is different and it may take some time to find just the right combination of medications and treatments to help your dog stop the itch. But by working closely with your veterinarian and revising the treatment plan as needed, both you and your dog can get relief.
- webmd.com: Yeast Infections in Dogs
- mercola.com: Itchy, Smelly Dog? Yeast Infection May Be the Problem
- Vetinfo.com: Yeast Infection in Dogs Feet
- Petwave.com: Treating Yeast Infection in Dogs
- Dogsnaturallymagazine.com: 5 Natural Solutions for Yeast in Dogs