172 Common Diseases of the Horse 



with a considerable amount of success, is an operation on the carti- 

 lages in the inside of the larynx or internal throat. It consists in 

 stripping the lining membrane of the affected cartilage, so that as it 

 heals the cartilage is pulled out of the air passage. The disease 

 invariably attacks the left cartilage, and when the membrane is 

 removed the healing process causes a contraction of the tissues, 

 which pulls back the paralysed cartilage from obstructing the 

 middle of the air passage to the side, and thus allows the air to 

 enter unimpeded. The operation demands very considerable skill, 

 and at present is only carried out by a few veterinary surgeons. 

 It involves great expense, and should not be carried out except on 

 valuable animals. 



In order to enable sufferers from wind infirmity to carry out 

 their work in a satisfactory manner, very careful feeding is required. 

 As much nourishment as possible must be provided, with a mini- 

 mum of bulk. Concentrated food must therefore be used, such as 

 oats and beans, with small quantities of hay, the most suitable 

 being well-grown best-quality meadow hay. Clover and rye grass 

 are not good, as they contain too many fat-producing substances. 

 They should therefore be avoided where possible; but if no other 

 kind is procurable care should be taken to see that it is of the best 

 quality — clean, sweet, and not in any way dusty or damaged. 

 Indeed, dusty and musty hay is supposed to be one of the most 

 frequent causes of unsoundness of the wind. Where a choice is 

 possible, hay containing very little or no clover should be used; 

 that containing the most rye grass is to be preferred; the second 

 or third year's ley would also be desirable, as it approximates 

 nearer to meadow hay. Bulk in any form must be avoided before 

 work ; small quantities of concentrated food and only a little water 

 should then be given. This can be compensated for by an increased 

 quantity when the day's work is over. 



Shivering 



Shivering is a disease of the central nervous system, that is to 

 say, of the brain or spinal column, and with our present knowledge 

 little can be said as to the actual cause that will be of interest to the 

 lay reader. The disease is fairly common, and once acquired it is 

 usually progressive in its nature; it reduces the value of the animal 

 probably more than any other disease of an hereditary nature. 



Symptoms. — Its chief characteristic is a loss of power, and a 

 quivering or twitching of certain groups of muscles of the body 

 when the horse is asked to back, or when the legs are picked up. 



