178 COMMON DISEASES. 



JViud puffs usually indicate considerable amount of hard 

 road work. 



Bog spavins. — These are enlargements of the synovial sac 

 of the hock joint and appear at the inner and front part of the 

 hock. They are often hereditary. 



Thoroughpins are very similar to bog spavins and wind puffs^ 

 except in location. Thoroughpins appear at the upper and back 

 part of the hock. They may or may not connect with the synovial 

 sac of the hock joint. 



Open joint. — Lameness from open joint is quite common 

 aTTTcmg city horses. This usually results from punctures of the 

 synovial sacs and the entrance of foreign matter, resulting in an 

 acute inflammation or svnovitis. This form of lameness can 

 usually be very easily detected, and the cause recognized. It is 

 very serious under all circumstances and frequently results in 

 loss of the animal. 



Curh. — This is a result of an injury or strain at the back 

 of the hock joint and is characterized at first by a hot, sensitive 

 swelling just back of the lowest part of the hock joint. After 

 the period of swelling and inflammation subsides there is apt to 

 remain a hard tumor, particularly on what is known as curby 

 hocks. In cases of young animals given proper treatment the re- 

 maining enlargement may be very slight or may practically dis- 

 appear. 



Capped hock. — Capped hock is not usually a cause or condi- 

 tion of lameness ; but is mentioned at this place for other reasons. 

 This is an unusual prominence at the point of the hock and 

 produced by bruises. Some horses get it by backing up against 

 the stalls and striking so as to injure the point of the hock. 

 Other cases are produced in car shipments. In other cases there 

 seems to be a natural tendency and the disorder is brought about 

 by very slight injuries. The first swelling may usually be reduced 

 by prompt treatment, but it returns with very slight injury and 

 after several attacks is apt to be permanent. This does not in- 

 jure horses for actual use, but is unsightly and materially reduces. 

 the sale value. 



