THOROUGHPIN.
Cause.—Generally due to some irritation of the hock joint such as severe sprains from animal jumping, slipping, kick or falling through a culvert or bridge or it is frequently hereditary; so be very careful in choosing a sire when breeding.
Symptoms.—Sometimes there is lameness when the Thoroughpin is first noticed, but it will gradually disappear as soon as the inflammation ceases. There will be a puffy, soft enlargement which occurs at the upper and back part of the hock, beneath the great tendons. Generally both sides are enlarged and puffy, but occasionally it happens that one side only is involved. Thoroughpin is also a forerunner of Bog Spavin, as they generally are connected; as you are aware the hock contains joint oil as all other joints do, retained in place by a thin, white fibrous membrane. Irritation of the hock joint tends to develop an extra large quantity of joint oil, and the hock is less protected by tendons where a Thoroughpin or Bog Spavin occurs—hence those puffy swellings are filled with joint oil and are connected. If you press on one side of a Thoroughpin, you will see the other side bulge out. If you press on a Bog Spavin and there is a Thoroughpin present, you will see it bulge on either side of the Thoroughpin—or vice versa.
Treatment.—If on an old horse and the Thoroughpin is of long standing, treatment is unsatisfactory, but on the other hand, if the animal is young it can be successfully treated with Tincture of Iodine, one ounce; Gum Camphor, two ounces; Gasolene, one pint. Mix well and rub in with nail or tooth brush twice a week. Keep the animal quiet as possible, as the results will be accomplished much sooner. Never attempt to open or lance a puffy swelling about a joint, as it contains joint oil. The result would be an open joint.