Its prevention is best secured by requiring moderate work only, and at the proper road-paces—viz., walking and trotting—keeping the feet moist, wetting them occasionally during a long journey, and regularly stopping them directly after each day’s severe work.—[See “Grooming,” page 12.]
Navicular Disease is, unfortunately, a very common one with horses; and when the delicate structure of the foot is considered in connection with the rough usage the creature gets on hard roads while carrying a heavy weight on his back, it is only surprising that the feet bear such jarring at all.
The navicular is the small pulley-bone over which the flexor tendon passes, and being the most active of any of the foot-bones, is the most likely to be injured by ill usage ([see page 128]). The symptoms are lameness, with more or less pointing of the foot when at rest, and heat towards the quarters of the lame foot.
Unlike laminitis, the lameness is inconsiderable at first, and increases as the disease progresses.
Being so deep-seated, it is very difficult to cure. In the incipient stages the most effectual remedy appears to be the insertion of frog-setons, requiring the assistance of a veterinary surgeon. In most instances the case is hopeless, and many a fine horse is sold to limp out a life of misery, drawing a hack cab, or, with a refinement of cruelty, is subject to the operation of unnerving the foot, which, by destroying sensation in that part, enables the animal to travel without apparent lameness, though the disease continues to progress till part of the foot has been known to drop off in work. Being a result of work to which all horses are liable, no mode of prevention can be recommended.
Lateral Cartilages.—Another ailment of the foot is more common than is generally supposed, called “Disease of the Lateral Cartilages.” It requires the skill of an anatomist to decide upon its presence. In fact, this and navicular disease are both very obscure in their origin and diagnostics, and a surgeon only can properly deal with them, as well as with all other diseases that are not very distinctly marked, and in their early stages not important.
Thrush.—A disease of the frog: the cleft becomes eaten away, and a foul matter is secreted. It more frequently attacks the hind than the fore feet.
By some it is said to be constitutional, but it is much more probably the result of neglect of the foot in the stable, the hind feet being oftener affected, from the fact of the urine and fæces coming more immediately under their tread.