THE HORSE IN SICKNESS AND DISEASE 429 



ounce of each drug rubbed down with one ounce of water. 

 Or place opium and camphor on the poultices ; or rub the 

 enlargement with equal parts of chloroform and camphorated 

 oil. The pain having subsided, and the heat being banished, 

 apply with friction some of the following ointment. It may 

 i-educe the disease by promoting absorption ; at all events 

 it will check further growth by rendering further deposit 

 almost an impossibility : 



Iodide of lead 1 ounce. 



Simple ointment 8 ounces. 



Mix." 



Bone-spavin is an exostosis, or deposit of bone on the 

 inner side of the hock, which, when low, is called by the 

 horse-dealer a "jack"; it corresponds to splint in the fore 

 leg, and originates at the head of the splint bone. The 

 " high spavin " is the most mischievous, as it locks the 

 joint, or renders the motion of the hock excruciatingly 

 painful, the tendons having to move over the rough, bony 

 deposit. The mode of lifting the hind leg in the trot will 

 show spavin : the foot, instead of being freely raised from 

 the ground, and slightly rotated outwards, drags, with the 

 toe pointed stiffly forward, describing a much less curve in 

 its passage through the air. The toe being thus brought 

 forward, is worn blunt with the shoe. Look then at the 

 horse's shoes (if worn), and see the horse when first brought 

 out of the stable ; when warm, the stiffness, in less severe 

 cases, will disappear. Horses with " sickle " or " cow- 

 hocks," i.e., with the great joints of the hinder limbs 

 approaching each other like the knees of a knock-kneed 

 man, are most liable to spavin, thorough-pin, and splint. 



THOROUGH-PIN. 



This is of the nature of bog-spavin, and allied to the 

 "wind-galls" of the farrier. We have more than once 

 mentioned the bursae mucos89 as the seat of disease. There 

 are two situations in which thorough-pin appears ; one 

 rather above the point of the hock ; the other below it. 

 Thorough-pin derives its name from the circumstance of 

 its appearing as a round swelling on both sides of the hock, 

 between the flexor of the tendons of the foot and the 



