Types and Market Classes of Live Stock 529 



over-feeding on grain, causing indigestion, irritation of the alimentary 

 tract, and inflammation of the fleshy laminae through sympathy. 

 Other causes are unusual excitement, bad shoeing, over-exertion, ex- 

 haustion, rapid changes of temperature, or any other agencies of an 

 over-supply of blood to the fleshy laminae, resulting in congestion and 

 inflammation. But it is the after-effects which are of most interest to 

 us here. The disease sometimes becomes chronic, and this seriously 

 affects the secretion of the horn. The toe of the hoof turns up, the 

 heels become longer than natural, while the hoof near the coronet is 

 circled with ridges like those of a ram's horn. These ridges are wide 

 apart at the heel, and close together in front, and are due to periods 

 of interference with the growth of horn simultaneous with the inflam- 

 mation of the fleshy laminae. Because of the high heel and turned-up 

 toe, the leg knuckles at the fetlock joint. Usually, accompanying 

 these defects, the sole is found to be thin, convex, and weak, and will 

 stand but little wear. Because of the convexity, the diseased tissues 

 bear unusual weight, and such animals are generally incurable cripples. 



Grease is not an unsoundness, but is such a troublesome and 

 common complaint that brief mention is here given. It is a skin dis- 

 ease appearing nearly always in the hind cannons. Draft horses are 

 more subject to it than light horses. Some individuals are predisposed 

 to it — those with coarse skin and coarse feather. Other horses have 

 it as a form of parasitic mange, denoted by a greasy condition of the 

 skin, congestion of the skin, erect hair, and offensive odor due to dis- 

 charge from the sores. There is a constant itching and the horse rubs 

 the part, producing thickening and wrinkling of the skin. Treatment 

 varies. Half an ounce of Fowler's solution of arsenic night and morn- 

 ing in the feed, burning with hot iron, applying hot linseed poultices, 

 dressing with lead lotion, giving a mild physic, decreasing amount of 

 feed allowance — all these furnish good methods of treatment. 



Hip down is a fracture of the point of the hip, often caused by the 

 animal striking the part against the door post of the stable. It causes 

 a flatness and sometimes the broken piece of bone may be felt. It is 

 best detected by standing squarely behind the animal and viewing 

 it across the hips. It constitutes a blemish. 



Navicular disease is a chronic inflammation involving the navicular 

 bone, the navicular bursa, and the flexor tendon of the foot. It is 

 brought on by repeated bruising. Light horses are affected much 

 oftener than heavy horses. The hind feet are seldom affected. It is 

 practically never found in mules. One-third of the weight falling on 

 the leg is sustained by the little bow-shaped navicular bone, and the 

 bone in turn is supported by the flexor tendon of the foot, (See Fig, 

 153,) Such defects as an insufficient plantar cushion, a small frog, and 



