Yeast dermatitis is a fairly common inflammatory skin condition in pets. The condition is caused by overgrowth of the Malassezia species of yeast (different to any yeast used in pet food), which are normal inhabitants of the skin, ears and mucocutaneous areas.
Yeast infections are particularly common in hot, humid environments. The infections occur when the yeast reproduces uncontrollably, overpopulating and invading the areas where it normally resides. Malassezia is a normal inhabitant of your dog's or cat's skin, but it becomes problematic only when it changes from a harmless to a pathogenic form. The precise causes of this transformation are unknown, although factors that suppress the immune system are often involved. Some factors that may contribute to yeast infections include allergies to fleas, inhalant/contact allergies, prolonged use of steroids or antibiotics, hormonal disorders like hypothyroidism or Cushing's disease, chemotherapeutic drugs and external skin parasites.
Concurrent bacterial skin infection also may cause an increased risk for yeast overgrowth. Yeast overgrowth will often result in increased oil production by the skin, causing increased itching that can create secondary sores and providing an even more supportive environment for the yeast to thrive.
The yeast in our pet food is a Saccharomyces yeast and is no relation to the one causing the infections(s). This species of yeast used is classed as a raw material and is not related to the species causing a yeast infection.
Yeast in pet food or via an ingredient cannot cause a yeast infection in a pet.
Your vet will be able to advise you on the best treatment for your pets yeast infection and there is no need at all to change your pet's diet.