What is fungal dermatitis in dogs?
Fungal dermatitis is also known as a yeast infection or Malessezia dermatitis, as it’s caused by the fungus Malessezia pachydermatis.
This fairly common inflammatory skin condition is referred to as a yeast infection, and can occur when the yeast that normally lives in your pet’s ears, mucocutaneous areas and skin reproduces uncontrollably and overpopulates these areas.
What causes fungal skin infections?
We know that yeast thrives in hot, humid environments, and infections can happen if your pet’s immune system is compromised or if they are taking strong immunosuppressive drugs. An increase in the amount of oils produced on the skin, or excess skin oils, can cause the condition.
Other yeast-like organisms or fungi may invade the circulation system and cause issues in your dog’s organs. These more serious fungi can include histoplasmosis, cryptococcus and Valley Fever, among others.
Fortunately, fungal dermatitis is not contagious, but can recur unless the underlying skin condition or allergy is controlled with medication.
As for which breeds are predisposed to yeast infections, be on guard if you’ve got a co*cker Spaniel, Shetland Sheepdog, Dachshund, Basset Hound, West Highland White Terrier, Silky Terrier, Maltese Terrier, Australian Terrier, Poodle, or Lhasa Apso.
What are signs and symptoms of fungal dermatitis?
When harmless malassezia changes to a pathogenic form, it can become problematic and result in symptoms such as:
- Skin irritation
- Inflammation
- Intense itchiness
- Flaky, crusty or scaly skin
- Thickened/”elephant” skin
- Ear infections
You may especially notice these signs between your four-legged friend’s paw pads and nails, and on the neck, nasal folds, armpits and anal area. Also check around his years. Secondary symptoms can include a sticky discharge, skin redness or sores.
Your dog’s coat is often a good indicator of their overall health, and that’s also true in cases of yeast infection; if her coat is greasy or there are signs of hair loss, or foul-smelling skin, she should see a vet.
How is fungal dermatitis in dogs diagnosed?
Your vet may use any of these techniques to collect a sample from your dog so his infection can be diagnosed and treated:
Skin biopsy - The most invasive diagnostic test uses a biopsy punch to obtain a small piece of skin. However, this provides the most complete diagnostic data.
Cotton swab sample - The skin is rubbed with a moistened swab to collect yeast organisms. Impression smear - A microscope slide is pressed onto the skin to collect yeast organisms. Acetate tape preparations - A piece of clear tape is applied to the skin to collect yeast organisms.
Skin scrape - The skin is scraped with a blade so yeast organisms can be collected.
How is fungal dermatitis treated?
There are a number of options for treating yeast infections in dogs, including oral or topical solutions. Sometimes your vet will prescribe a combination of both if the case is severe.
Oral Treatment
This type of treatment would be used for persistent, severe or chronic cases of yeast dermatitis. Bacterial skin infections can also accompany the condition and require 4 to 12 weeks of antibiotics. Systemic anti-fungal medications are often in this category and can include itraconazole, fluconazole and ketoconazole.
Use caution with these because although they are highly effective, these drugs can have potential side effects for your dog’s liver. Routine blood tests and close monitoring are a must.
Topical Treatment
An essential step to treating yeast dermatitis is to use a medicated shampoo containing benzoyl peroxide or selenium sulfide. After a first “degreasing” cleansing session has taken place with the shampoo, taking at least a 10-minute bath with an anti-fungal shampoo is recommended. Effective topical treatments are needed every 3 to 5 days for 2 to 12 weeks to eradicate the infection.
If an infection is diagnosed on the ears or on just one or two isolated spots on the skin, your dog may require a topical ointment for daily use.
What is the prognosis for treating fungal dermatitis?
Yeast infections can generally be treated long-term and you may see less itching within a week of starting the prescribed treatment.
If your dog has an underlying issue such as a compromised immune system or allergy, how well these conditions can be treated and controlled will determine the outcome. Some dogs will experience secondary yeast or bacterial skin infections along with severe skin allergies - sometimes two to three times each year.
If this is the case, your veterinarian can develop a custom treatment plan for your dog to help manage the condition.
