What is yeast dermatitis?

Yeast dermatitis or Malassezia dermatitis is caused by the fungus Malassezia pachydermatis. It is an extremely common cause of skin disease in dogs.

What are the clinical signs of a yeast skin infection?

The most common clinical signs of Malassezia dermatitis are:

o Thickened skin (“elephant skin”)
o Hyperpigmentation (darkly pigmented skin)
o Musty odor{{more}}
o Scales and crusty, flaky skin
o Itching and redness
o Chronic or recurrent otitis externa or ear infections

How does a dog get a yeast skin infection?

The skin is host to innumerable bacteria and fungi. Under normal circumstances, these organisms do not cause a problem and are kept under control by the immune system. If conditions on the skin change or if the immune system is suppressed these bacteria and fungi can cause infection. These types of infections are termed opportunistic infections. If the number of yeast organisms on the skin increase, a yeast skin infection results.

A common cause of a yeast skin infection is an increase in the amount of oils produced on the skin. This is most frequently associated with allergic skin disease. Another common cause of excess skin oils is seborrhea oleosa. Some dogs will have an immune deficiency so that they ineffectively fight yeast infections, and this will result in chronic infection. Dogs that receive immunosuppressive drugs such as corticosteroids (steroids) may also be unable to effectively prevent yeast infections, so may develop a chronic yeast infection. Yeast dermatitis is not contagious; your dog did not get this infection from another dog. Opportunistic yeast infections often recur unless the underlying allergy or skin condition is controlled.

How is yeast dermatitis treated?

Treatment for yeast dermatitis may be topical, oral, or a combination of both, and is based on the severity of your dog’s condition.

Topical treatment

Treatment with medicated shampoos is a vital part of treating yeast dermatitis. Bathing with an anti-fungal shampoo containing chlorhexidine, miconazole or ketoconazole is recommended. It is important the anti-fungal shampoo remain in contact with the skin for at least fifteen minutes. To be effective, this topical treatment is required every 3-5 days for two to twelve weeks. If the infection is in the ears or in only one or two spots on the skin, a topical ointment may be prescribed for daily use.

What is the prognosis for yeast dermatitis?

The prognosis for Malassezia dermatitis is generally good. While the condition usually requires long-term treatment, the majority of cases respond favorably and the itching is reduced within a week of beginning therapy.

In cases with underlying allergies or immune compromise, the prognosis is based on the ability to control those conditions. It is not uncommon for dogs with severe skin allergies to have recurrent secondary yeast or bacterial skin infections, sometimes two or three times a year.

For further information, contact:
Dr. Collin Boyle
Unique Animal Care Co. Ltd. Tel: 456 4981
Website: www.uniqueanimalcare.com