Laminitis is generally known to the farrier by the term “founder.” Laminitis is an inflammation of the sensitive laminae of the feet, destructive to the tissues affected.
The causes of laminitis are many. The most common causes are exhaustion, over-exertion, concussions, rapid changes in temperature, indigestion of various foods, and purgatives. Concussion is the cause of laminits when the horse is driven at a high speed when in a condition unfit for such exertion, and it is the more easily brought on when a weight is placed on top of the foot, called a toe weight, causing the foot to be thrown out against the ground with force. The toe weight in the shoe is also productive of the same result, but not to the same extent as is the weight on the top of the foot. A horse taken from the farm and driven hard on macadamized roads or paved streets is liable to contract such inflammation. Long drives and heavy pulling are often the causes of this disease. Horses on sea voyages will be affected by this trouble. The exhaustion of the laminae resulting from the continual strained position in which the horse is compelled to stand on account of the rocking motion of the ship. Rapid change of temperature is another cause, such change being induced by drinking cold water while in an overheated condition, or from cold winds-the horse being left in a cold and windy place when wet with sweat.
It is claimed that barley, wheat and corn are productive of this disease in some horses. When one of the feet is incapacitated from any cause the other foot is called upon to do double duty and is soon exhausted, and congestion, followed by inflammation, results. When one foot only becomes laminitic, the other member will be affected later, not from sympathy but because this member is doing the work of two.
All old authorities agree that metastatic laminitis is a reality, while many of our modern writers deny this. In cases of chronic laminitis it is found that the toe of the foot turns up, the heels are longer than natural. The cause of this many be ascribed to the fact that the coronary band in front produces horn very slowly, while in the heels the production is greater. The result is that the hoof is creased like the horn of a ram. These creases or ridges are also found in other diseases of the foot, but they are then equally distant from each other all around the foot, while in laminitis they are found to be wider apart at the heels and close together in the front. (See No. 4, Plate 31.)
Laminitis is a dangerous diseases and the farrier is not expected to do more than shoe the animal so as to minimize the jar and concussions. When the horse is excessively lame in one foot, remove the shoe from the other member and apply cold water frequently as a tonic to prevent laminitis in this foot from too much strain. If the horse remains standing, place him in the sling so as to relieve the pressure in the feet. (See Plate 28.) In severe cases, with profuse suppuration of the laminae, it is best to destroy the animal and end the suffering.
In chronic cases where the horse is used for work, shoe with light shoes and sharp but short calks. If the horse shows lameness and tenderness use rubber shoes. The hoofs should be kept soft to prevent contraction which would greatly aggravate the trouble.
Pumiced sole is also known by the term drop sole. By this is meant that condition of the foot in which the horny sole, especially at the toe, crumbles away, leaving the sensitive tissues more or less exposed. It is often the result of laminitis, but may be seen when the conditions necessary for inducing are present.
The horny tissues become weak, cheesy or spongy. When the soft tissues are destroyed it often happens that the horny sole crumbles away under the pressure of the coffin bone, and the end of the bone comes out through the sole. In this disease the sole becomes convexed and it is a hard matter for the farrier to fit a shoe to the foot, as the wall is not even with the sole, but much shorter than in the healthy foot. In such cases I would recommend rubber shoes. In preparing the foot for the shoe, shorten the toe of the foot as much as possible. The foot being long there is danger of the coffin bone breaking through; for the longer the foot the harder the pressure of the bone against the sole. The sole should not be pared off any, for it is thin enough as it is. This kind of cripple is generally incurable unless the trouble was brought on by a puncture or wound, in which event a cure may be effected when the wound is healed.