46 DISEASES OF THE SYNOVIAL MEMBRAXES AND ARTICULATIONS. 



Diagnosis. The diagnosis presents no difficulty, but the lesions 

 must be distinguished from those due to tuberculosis in this region, 

 rheumatic arthritis, and the specific arthritis seen in milch cows. 



The prognosis is grave, for the disease renders animals useless 

 for work. 



Treatment. Best, cold moist applications, and massage constitute 

 the best treatment in the early stages. Should swelling persist, one 

 may afterwards apply a smart blister or even tap the joint aseptically, 

 drawing off the fluid and then applying the actual cautery. Irritant 

 injections must be avoided. 



DISTENSION OF THE SYNOVIAL CAPSULE OF THE HOCK JOINT. 

 Bog Spavin in the Ox. 



Bog spavin is frequent in working oxen and in oxen from three to 

 five years old. It is due 1o strain in draught or to strain produced in 

 rearing up at the moment of covering. Old bulls, heavy of body, and 

 stiff in their limbs are predisposed to it. 



Symptoms. The symptoms usually develop gradually and without 

 lameness, but sometimes declare themselves more rapidly wdth lameness, 

 accompanied by marked sensitiveness on palpation. At first the hock 

 show^s a generalised doughy swelling, soon followed by dilatation of the 

 articular synovial sac. Somewhat later four different swellings appear — 

 two in front, separated by the tendons of the common extensor and 

 flexor metatarsi, and tw^o at the back, extending inside and outside to the 

 flexure of the hock. 



Diagnosis. The only precaution required in diagnosis is to avoid' 

 confusion with articular rheumatism. 



Prognosis. The prognosis is rather grave in the case of working 

 oxen, and even of bulls ; often slaughter is preferable to treatment. 



Treatment differs in no respect from that of distension of the stifle- 

 joint. In young bulls aseptic puncture and drainage of the joint, 

 follow^ed by the application of the actual cautery, probably give the 

 best results. 



DISTENSION OF TENDON SHEATHS IN THE HOCK REGION. 



Like the preceding, this condition is rarely seen except in bulls and 

 w^orking oxen. It is characterised by dilatation of the upper portion of 

 the tarsal sheath, one swelling appearing on the outer side, the other on 

 the inner. 



The differential diagnosis is based on the position of these synovial 

 sacs, which are quite close to the insertion of the tendo-Achillis, and on 

 the absence of any swelling in front of the joint. 



