The smell says it all. The unmistakable rotting odor emanating from a hoof, usually accompanied by a black-colored discharge under or around the frog, deep sulcus, cracks or crevices within the hoof — these are the first tell-tale signs that you’re dealing with the organism, Spherophorus neaophorus, otherwise known as thrush.

Thrush, perhaps the most common foot problem that horse owners ask about, eats away at the tissues of the frog and inner hoof. If treated promptly and correctly, thrush rarely causes lameness.

“Thrush is a degenerative condition that, if caught in its early stages, is easily managed, but can become quite severe,” says Ray Miller, a farrier from Lyndon Station, Wis., with over 44 years in the shoeing business. “The fungus or bacteria exists in the clefts on either side of the frog, and horses with long toes and contracted heels tend to develop deep frog clefts and are particularly susceptible to this infection.

“The prevailing symptom of thrush is the accumulation of a black, foul-smelling, moist material. This discharge drains from the side grooves of the frog.”

In 2006, with advancements in hoof-care knowledge and a wide variety of topical thrush medications readily available, thrush isn’t thought to be too serious a hoof-care concern. But if left untreated, the condition may progress and worsen until lameness appears.

“Lameness occurs when the infection destroys the horn of the frog and extends into the sensitive tissues,” says Miller.

Danny Ward, the International Horseshoeing Hall Of Fame farrier from Martinsville, Va…