Definition
Malassezia is a yeast that is naturally found on the skin of dogs and has a particular affinity for fat. Infection occurs when this yeast reproduces abnormally and develops into an out-of-control population.
How Yeast Infections Affect Dogs
Yeast infection cause oily skin, inflammation, severe ear infections with voluminous smelly discharge, irritated skin between the paw pads, nasal folds, anal area and neck, weeping skin sores and an overall foul body odor. They frequently are extremely itchy and can lead to self-trauma from scratching and rubbing. Certain breeds of dogs are prone to yeast infections either because of genetics or because of breed-characteristic thick and wrinkled skin that provides a warm, moist environment for yeast overgrowth.
Causes of Yeast Infections in Dogs
“Yeast” is an often-used but poorly-understood term. “Yeasts” are unicellular, nucleated, usually rounded fungi that reproduce by budding (asexual reproduction where a portion of the cell body is thrust out, pinched off and becomes a separate, new individual yeast cell). As Malassezia is a normal inhabitant of canine skin – especially in and on the ears - the signs caused by infection with this yeast only occur when the organism overgrows abnormally. This often is caused by some type of immunosuppression in affected dogs, which can be caused by steroids, allergies to food, chemicals, parasites or other things. Removal of the offending allergen and treatment of the yeast overgrowth usually resolve the clinical signs. Yeast overgrowth leads to increased oil production from the dog’s skin, severe itching and continual scratching that can create sores and weaken the skin, providing an environment where even more yeast can flourish.
Preventing Yeast Infections
Malassezia yeast infections are common in dogs, but thankfully are somewhat preventable and largely treatable. Dogs with conformational predispositions to developing these infections should be kept especially clean and dry in and between their ear and facial folds and other skin wrinkles. Prescription treatments for infection by this organism include systemic oral anti-fungal medications, medicated shampoos, solutions, lotions, sprays, wipes or powders and addressing the underlying cause of the condition.
Special Notes
Only a veterinarian can properly assess a yeast infection and prescribe appropriately tailored protocols to eliminate yeast overgrowth, reduce the dog’s discomfort, manage or eliminate secondary bacterial infections and reduce the chances of reinfection. The prognosis for dogs with yeast infections is quite good. However, many dogs will require periodic lifelong treatments to manage future outbreaks.