186 DISEASES OF THE FEET. 



CAUSES, PREDISPOSING CAUSES, AND PREDISPOSITION. 

 — 1. Want of exercise is a frequent cause of laminitis among horses 

 wKioh are sent on long sea voyages and which are not able to lie 

 down, as I have pointed out in " Horses on Board Ship." In such 

 cases, it is more correct to refer the disease to inaction, than to 

 long-continued standing ; because such animals are far more liable 

 to get laminitis during fine weather, than when the sea is rough, 

 Also, their risk of becoming affected is greatly decreased by giving 

 them even a quarter of an hour's daily exercise, which is seldom 

 possible, except when the equine cargo is small as compared to the 

 size of the vessel. Inaction can also be a predisposing cause, as 

 we shall see in the following paragraph. Laminitis sometimes 

 occurs from want of exercise on land, when horses are tied up in 

 stalls or boxes, owing to injury or disease, and are not allowed to lie 

 down ; and also when they refrain from lying down, owing to the fact 

 of their suffering from certain diseases, especially those of the chest. 

 Horses, under natural conditions, spend such a large proportion 

 of their time in almost constant movement, that the usual long 

 periods of enforced idleness in the stable have a very deleterious 

 effect on the soundness of the legs, by the consequent congestion 

 which is set up, particularly in their feet, 



2. Excessive work, especially at fast paces and on hard ground. 

 The amount of work capable of producing the disease, is propor- 

 tionate to the ability of the feet to bear it with impunity. Here, 

 continued want of exercise has a particularly strong predisposing 

 effect. Thus, horses which in ordinary working condition could 

 trot for thirty miles on a hard road without any bad result, would 

 in all probability get laminitis, if walked, say, five miles imme- 

 diately on landing after a month's journey by sea ; provided they 

 had to stand up the whole time, and had had no exercise. Equally 

 bad effects would of course be produced under similar conditions 

 on land. Inattention to the predisposing influence which want of 

 exercise has in setting up laminitis, has been the cause of many 

 thousands of recently landed horses being rendered unfit for service 

 during the late South African war. Laminitis brought on by 

 excessive work is much more intractable than laminitis due to all 

 other causes, except that of infection of the womb after foaling. 



3. Intestinal congestion, caused by indigestible food, severe pur- 

 gatives, etc. Purgatives like aloes and Epsom salts act by pro- 

 ducing congestion of the mucous membrane of the intestine, which 

 causes a discharge of watery fluid from that membrane into the 

 bowel, and consequent purging. When food is to blame in this 

 respect, it generally consists of wheat, barley, or maize given in 

 excessive quantities. 



4. Inflammation of the womb from foaling {septic metritis). 



