There are some horses which walk down hill in so peculiar a manner that they may be supposed to be lame. This kind of walk has been termed a "three-cornered walk." The animal sways from side to side most awkwardly, his hind-quarters being turned to one side or the other, going forwards broadside on, similar to an animal going down hill with a heavy load behind him.
If a sound horse, when trotting, has his head turned towards the man who leads him - going in a sort of "left shoulder in "fashion - he may appear to be lame on the near fore-leg, on account of stepping shorter with it than with the off fore.
Some horses, when trotting very fast, appear to go lame behind, by reason of the hind legs not being able to keep time with the fore.
I have known a horse always go lame in harness, although he went quite sound in saddle, the cause being that, on a previous occasion, when working between the shafts, one of his shoulders became galled, and continuing the work for some time in this state, he acquired the habit of bearing against the collar as much as possible with the other shoulder.
A horse suffering from navicular disease goes up hill sounder than he goes down; the reverse is the case in laminitis.
When the animal is lame behind, the disease is generally in the hock; when in front, in the feet of cart horses, or in the suspensory ligaments of those that are used for fast work.
When a horse goes lame on a fore-leg without any perceptible cause, and wears away the toe of the shoe, we may suspect that foot of navicular disease. But if he goes on the heel, the probability is that he has either laminitis, "seedy toe," or incipient ring-bone. If the lameness be behind, and the toe of the shoe becomes worn, we shall generally find that it is due to spavin.
Side-bones are almost peculiar to cart horses, sore shins to race-horses, and navicular disease to riding, cab, and carriage horses. Navicular disease and occult spavin are hardly ever found in horses under seven years of age.