Hair Balls hi the Intestities — Hot^se. Egagropiles. 321 



found in various forms in all the domestic animals. In horses 

 they occupy the caecum and colon and are most frequently com- 

 posed of the fine vegetable hairs that surround the grain of the 

 oat, or the leaf of clover, of the woody tendrils of vines, and of 

 the hairs of themselves and their fellows taken in at the period of 

 moulting. Tiiey sometimes contain a nucleus of leather or other 

 foreign body which has been swallowed but in many cases no such 

 object can be found, the hair having become rolled and felted by 

 the vermicular movements of the .stomach and intestines. An 

 admixture of nuicus assists materially in the felting, and calcareous 

 and magnesian salts may make up the greater part of the mass, 

 rendering it virtuall)^ a calculus. They may further have a large 

 admixture of straw and vegetable fibres of larger .size than oat or 

 clover hairs. They are most frequent in horses kept on dry food, 

 (sweepings of oat-meal mills) and at hard work, and which .show 

 depraved appetite and lick each other. Omnibus hor.ses suffer 

 more than army horses. Skin diseases, by encouraging licking, 

 contribute to their production. 



Symptoms. In the great majority of cases hair balls do not 

 seriously incommode the horse. The}' do not attain a large size, 

 and being light do not drag injuriousl}^ on the intestine and 

 mesentery. They do, however, retard the movement of the in- 

 gesta, and when grown to a considerable size they may block the 

 intestine, more particularly the pelvic flexure, the floating colon 

 or rectum. Under such conditions they produce colics which may 

 be slight, transient, and recurrent, or severe and even fatal, having 

 all the characteristics of complete obstruction from other cau.ses. 

 Fermentations, tympanies, and straining without defecation are 

 common features. When the ob.struction takes place in the pelvic 

 flexure, the floating colon or rectum, it may often be detected by 

 rectal exploration. When complete ob.struction occurs all the 

 violent symptoms of that condition are present, and these ma}'^ 

 pass into those of rupture (Peuch, Leblanc, Neyraud), and shock 

 or peritonitis. If the animal has pa.s.sed hair balls even months 

 before, the colics may with considerable confidence be attributed 

 to other balls of the .same kind. 



Lesions. In case of death there are the usual lesions of gase- 

 ous indigestion, with or without enteritis, but with the accumu- 

 lation of a great quantity of liquid contents, above the ball, 



