Every dog has small amounts of yeast on his skin. In most cases, it doesn't cause a problem. However, dogs sensitive to yeast might suffer from dermatitis resulting from the fungus Malassezia pachydermatis. Eventually, an affected dog's skin looks like it belongs on an elephant -- hence the term pachydermatis. It's a frustrating condition, requiring constant vigilance.
Caused by the Malassezia pachydermatis fungus, the dermatitis yeast infection include hair loss, incessant scratching resulting in lesions, skin darkening and greasy and irritated skin. Your dog gives off a bad smell from the yeast and infection. This infection isn't contagious, so an affected dog won't spread it to other animals in the household. Even if your dog recovers initially, he's prone to coming down with malassezia dermatitis again. However, careful management can usually keep it under control.
Determing the Cause
While the symptoms of the yeast infection must be treated, your vet must also determine the cause. The excess skin oil that feeds the yeast often results from an allergic reaction. Your vet will perform skin testing for allergy diagnosis. If your dog receives steroids for another health issue, those drugs can compromise his immune system, allowing the yeast infection to take hold. Dogs with seborrhea, a condition resulting in overproduction of oil from the sebaceous glands, are ripe for yeast infections.
Your vet will recommend regular bathing with antifungal shampoos. First, your dog requires a bath with products containing ingredients such as benzoyl peroxide or selenium sulfide, which serve to get the grease out of your dog's skin. Then, the dog receives an antifungal bath during which the soap must remain on the body for a minimum of 10 minutes for effective treatment. Repeat the antifungal baths every few days for a period of up to three months. If your dog experiences only a small patch of malassezia dermatitis, your vet might suggest using topical cleansers and creams, rather than bathing the entire animal.
Topical treatments aren't sufficient for severely affected dogs. They require daily oral medications to beat this condition. While ketoconazole is the drug of choice, dogs with liver ailments can't take this medication. Ketoconazole often produces side effects including vomiting, diarrhea and appetite loss. Itraconazole is an alternative, as it involves fewer side effects. If your dog receives these medications, your vet will take regular blood samples for testing to ensure his liver values stay within normal range.