Navicular disease, sometimes called coffin-joint lameness, occurs among horses that are used for hard and fast driving upon the roads. If it is of long standing it is incurable.

Symptoms. - It is not always easily diagnosed by the inexperienced. There will be lameness, sometimes only on starting, then it will disappear: if you hold the foot up and tap with a hammer on or near the frog the horse will flinch: if the disease is of long standing the affected limb will have a neat, clean appearance and the hoof will be smaller than its mate.

Treatment. - If the lameness is of only recent occurrence a cure may sometimes be effected. Remove the shoe and apply hot poultices to the foot until the hoof is thoroughly softened, then rasp down the wall, making the toe the lowest, and dress out the sole. Fix a tub or tank with cold water and stand the horse in this five or six hours each day for two or three weeks. After this has been done apply the biniodide of mercury blister to the coronet often enough to keep it just moderately sore for two months. Shoeing with swelled heels to relieve the foot of frog pressure will sometimes prove beneficial.