296 PRINCIPLES OP VETERINARY SCIENCE 



rary or complete and permanent. The horse is said to be 

 "stifled" when this accident occurs. Slipping when getting up 

 in the stall, and stepping down from the stable floor to the ground 

 some inches lower, are movements that may cause the patella to 

 slip out of position. It may either snap back into place as soon 

 as the joint is flexed, or catch and remain stationary at either the 

 upper or outer side of the trochlea. In some cases it slips in and 

 out with every step without preventing locomotion, but rendering 

 the animal worthless, if long continued, by bringing about exces- 

 sive wear on the articular cartilages. In upward dislocation the 

 stifle joint is abnormally extended, which causes the leg to become 

 rigidly stretched backward and makes progression almost impos- 

 sible. Even with assistance the horse cannot bring the leg for- 

 ward. By suddenly moving the animal backward and to the side 

 the bone may slip back 'into position. If this is unsuccessful, 

 place a rope around the pastern and lift the toe forward and up- 

 ward; at the same time lift the patella upward with both hands. 

 An audible click will be heard when the bone slips back into place. 

 After-treatment consists in the application Of a stiff blister or the 

 firing-iron to the stifle to strengthen the tissues. 



Sprain of the fetlock joint results in momentary separation of 

 the joint surfaces and 'overstretching of the joint capsule and liga- 

 ments. The causes are traumatisms, like fast work on rough 

 ground and catching the foot between planks. When pas- 

 sively rotated pain is severe. Within a short time swelling, heat, 

 and lameness are noticeable. Treatment consists in rest and 

 moist heat. The application of a plaster-of-paris bandage gives 

 support and at the same time compression, both of which 

 hasten recovery. 



Deforming arthritis is seen in both young and old horses. Its 

 presence is shown by a deforming enlargement of the affected 

 joint. The causes may be infection through the navel while it is 

 yet raw; rheumatism; traumatisms. Lameness of a transitory 

 character that becomes gradually more persistent and permanent 

 is the first symptom. There soon develops a sensitive swelling 

 throughout the joint, and an effort is made to restrict joint move- 

 ment as much as possible. This may shortly result in a peculiar 

 gait even when walking. Figure 76 is a photograph of one of the 

 author's cases. It shows erosion of the articular cartilages, dis- 

 tention of the joint capsule, free joint bodies, and other degenera- 



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