Interfering shoes of different types are of material benefit in many instances.  Often the principle upon which corrective shoeing is based is that the mesial (inner) side of the foot is too low; the foot is consequently leveled and the inner branch of the shoe is made thicker than the outer, altering the position of the foot in this way.  This is productive of desirable results.  However, much depends upon the manner in which the foot in motion strikes the weight-bearing member as to the corrective measures that are indicated.  This belongs to the domain of pathological shoeing and the reader is referred to works on this subject for further study of this phase of lameness.

Lymphangitis.

Excluding glanders, in the majority of instances, lymphangitis in the horse, such as frequently affects the hind legs, is due to the local introduction of infectious material into the tissues as a result of wounds.  However, one may observe in some instances an acute lymphangitis which affects the pelvic limbs of horses and no evidence of infection exists.  Consequently, lymphangitis may be considered as infectious and non-infectious.

INFECTIOUS LYMPHANGITIS.

Etiology and Occurrence.—­Traumatisms of the legs frequently result in infection and when such injuries are near lymph glands, even though the degree of infection be slight, more or less disturbance of function of the muscles in the vicinity of such glands occurs and lameness follows.

The prescapular, axillary and cubital lymph glands when in a state of inflammation, cause lameness of the front leg, and the superficial inguinal and deep inguinal lymph glands not infrequently become involved also.  Because of the location of these lymph glands, they are subject to comparatively frequent injury and inflammation, causing lameness more often than other lymph-gland-affections.

Small puncture wounds in the region of the elbow are often met with.  These may be inflicted when horses lie down upon sharp stumps of vegetation or shoe-calk injuries may be the means of introducing contagium, and an infectious inflammation results.  Abscess formation, the result of strangles or other infection in the prescapular glands, may be observed at times.  Following castration, the inguinal lymph glands may become involved in an infectious inflammation and locomotion is impeded to a marked degree.  Horses running at pasture sometimes become injured by trampling upon pieces of wood, causing one end of these or of various implements to become embedded in the soft earth and the other end to enter at the inguinal region and even penetrate the tissues to and through the skin and fascia just below the perineal region.

Nail punctures resulting in infection frequently cause an infectious lymphangitis and a marked and painful swelling of the legs supervenes.

[Illustration:  Fig. 61—­Chronic lymphangitis.  Showing hypertrophy of the left hind leg, due to repeated inflammation.]