DEFECTS IX THE HORSE 



201 



in a thickening of the part, 

 as compared with the sound 

 hock. The occurrence of the 

 spavin is most easily seen by 

 standing directly back of the 

 horse ; it may also be seen 

 from the front by looking 

 back between the forelegs. 

 The gait of a badly spavined 

 horse shows a pronounced 

 lameness. The affected leg 

 shows some hitch in action, 

 and the weight is heavily 

 thrown on the sound leg, re- 

 sulting in some depression 

 of the hip on that side. The 

 occurrence of the bone 

 spavin may be determined 

 by the following method: 

 Grasp the lower end of the 

 cannon bone and flex the 

 joint as much as possible, 

 keeping the leg in this posi- 

 tion a minute or two. Then 



release the leg, and have the animal driven away at a trot, 

 the examiner standing behind the line of movement. In 

 case of spavin, the characteristic lameness of this disease 

 will be apparent. Bone spavin is regarded as a serious un- 

 soundness, and greatly damages the sale value of a horse. 

 It is more prevalent with light rather than heavy horses. 



Bog" spavin is a puffy swelling on the front and inside 

 of the hock joint. It is due to an inflammation of the 

 synovial sac of the joint from which results the production 

 of an abnormal amount of synovial fluid. When well de- 

 veloped this spavin is clearly seen, and feels soft to the 

 pressure of the fingers. It does not usually cause lame- 

 ness, though it may. The bog spavin is most common on 



Fig. 112. "Bog spavin is a puffy 

 swelling on the front and inside of 

 the hock joint." This right leg also 

 has a well-marked thoroughpin. 

 (Photo by courtesy College Veter- 

 inary Medicine, Ohio State Uni- 

 versity.) 



