130 THEORY AND PRACTICE 



The strongylus tetracanthus usually exists in large numbers 

 and produces extreme pain, for which we use irritating poisons 

 such as arsenic, sulphate of copper, sulphate of zinc, or sulphate 

 of iron in large quantities. 



Another cause of colic is exposure to cold and dampness. If 

 a horse falls down or lies down on the ice or snow, exposure to 

 the cold is likely to produce colic. Colic may be produced by 

 violence in the form of kicks, severe accidents, etc. 



Scmciology. — Colic usually comes on suddenly. The irritant, 

 whatever it is, irritates the hning of the bowel and nature will 

 submit to this disturbance only up to a certain point. Then she 

 gives away suddenly. The irritation sufficient to produce colic 

 may be accumulating for several days or it may do its work in a 

 few hours, but when the colic begins, it runs a rapid course. If 

 the horse is watched prior to the development of the disease, it 

 will be noticed that he gets uneasy first, may lie down and kick 

 his hind feet up, turn around, switch his tail, lie down and roll 

 and get up again. He may be quite comfortable for a few 

 minutes, then another cramp comes on a little more severe than 

 the preceding one. As a result he lies down and may attempt to 

 remain on his back, then goes through the same restless motions 

 again until he exercises himself enough to sweat. He rolls and 

 kicks and switches his tail until he feels easier. 



In the majority of cases nature cures the trouble. These vio- 

 lent contractions succeed in moving the obstruction along. Sev- 

 enty-five per cent of these cases will be well when the doctor 

 arrives. The pulse is increased in frequency due to the violent 

 exertion, but it is not altered in character until the trouble has 

 been running a considerable length of time with the possible 

 danger of enteritis. The exercise m.ay also cause an elevation of 

 temperature. 



Pressure on the belly may give relief, while in enteritis or 

 peritonitis, it increases the pain ; this is a means of diagnosis. 



According to the idea of the laity retaining the urine causes 

 colic, but this does not occur except when the horse has a habit 

 of urinating under certain favorable conditions and holds the 

 urine too long, thus causing a spasmodic contraction of the neck 

 of the bladder. This is painful in itself and of course he is un- 



