What Causes Yeast Infections in Dogs?

Yeast infections in dogs are caused by a fungus called Malassezia pachydermatis. According to the Pet Wave website, the symptoms of a yeast infection are inflamed and irritated skin, open wounds, chronic ear infections with foul-smelling discharge, and a generally unpleasant body odor. Yeast infections are usually a secondary infection caused by an underlying condition.
  1. Seborrhea

    • Seborrhea is a condition that occurs when the dog's skin builds up dead skin cells faster than it can slough them off. The result is an excessive buildup of flaky skin. There are two different types of seborrhea. Seborrhea sicca occurs when the skin is only scaly. The condition called seborrhea oleosa is characterized by excessive oil production in addition to scaly skin. Dogs with seborrhea oleosa often have an unpleasant body odor. The buildup of oil on the skin is a breeding ground for yeast and bacteria, so dogs with seborrhea often develop secondary yeast and bacterial infections.

      Seborrhea is caused by several different factors. PetEducation.com explains that primary seborrhea is a genetic disorder passed down from parents to their puppies. Secondary seborrhea is caused by hormone disorders, parasites and allergies, among other conditions. Medicated shampoos soothe the symptoms of seborrhea, but the underlying conditions and secondary infections must also be addressed.

    Bacterial Pyoderma

    • The Animal Health Consulting website describes bacterial pyoderma as an infection of the skin that is usually caused by the staphylococcus bacteria. There are two types of pyoderma infections. Superficial pyoderma is limited to the top layer of skin and the hair follicles, while deep pyoderma affects the tissues beneath the skin's surface. The primary symptom is small, red pus-filled bumps on the skin. These pustules leave a scaly, yellowish crust on the skin when they rupture. Most cases of pyoderma are caused by an underlying condition such as a hormone disorder, a parasite infestation or flea allergies. Yeast infections often accompany bacterial infections. Pyoderma is treated with antibiotics.

    Allergies

    • According to PetEducation.com, dogs with allergies often develop skin disorders. They frequently rub, gnaw and scratch at their skin, which leads to open wounds and patchy hair loss. The dog's ears produce too much wax in response to the allergy, and yeast and bacteria grow in the wax. The results are chronic ear infections and an overgrowth of yeast and bacteria on other parts of the body. Allergies are treated by avoiding the allergen. Anti-itch solutions and medicated shampoos soothe the itching and irritation. Omega-3 fatty acids help manage the symptoms of allergy. Finally, antihistamines are included as part of a comprehensive allergy treatment plan.