This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
Sprain of the back tendons of the leg (flexors perforatus and perforans) may occur from hard driving, especially on uneven ground, or it may come from heavy pulling. Allowing the toe of the foot to grow long, thus increasing the leverage, will make sprain of the back tendons more liable to occur.
Symptoms. - There will be heat and swelling, and the horse will show signs of pain if the tendons are pressed with the fingers. There will be lameness when traveling and it will be just the same on soft ground as on hard ground.
Treatment. - Have the animal shod with high heels and no toe calks, and apply cold water several times a day until all inflammation is removed. A blister made of equal parts of the biniodide of mercury and cantharidine blisters combined should be applied and repeated again in three or four weeks. Complete rest should be given the horse, not only while lame, but for several months, to allow the tendons to grow strong before he is put to work again. If blisters fail to relieve the lameness, the firing-iron should be applied; but this requires some experience to perform properly and should only be entrusted to a competent veterinarian.
This ligament lies between the flexor tendons and the back part of the bone of the leg from the knee downward. A sprain of the suspensory ligament is more serious than a sprain of the back tendons. Symptoms and treatment are the same as for the back tendons Firing and long rest will sometimes effect a cure in these cases when everything else has failed