786 SHOULDER LAMENESS FROM THROMBOSIS. 



The lameness increased with movement, and was distinguished by the lame 

 leg being so much adducted that it crossed the other leg. Seven weeks 

 afterwards the animal was killed as incurable. 



There is no difficulty in diagnosing such cases, but the prognosis 

 can only be based on a thorough knowledge of the local anatomical 

 changes. 



(3) Shoulder lameness may be caused by disease of the scapula 

 or humerus. Though fractures are generally easy to recognise, 

 fissures may elude the closest examination. Periostitis and the 

 formation of exostoses are common on the scapula and humerus. 



Gerke, in making a post-mortem of a horse which had suffered for two 

 years from shoulder lameness, found an exostosis on the inner side of the 

 head of the humerus. The connective tissue surrounding it appeared 

 thickened, and formed, along with the exostosis, an " extraordinary articular 

 surface." The radial nerve was smaller than on the sound side. The 

 horse moved the limb in circles, but could still place weight on it. The 

 lameness only occurred at a trot, but did not disappear with work. Similar 

 cases have repeatedly been seen. 



(4) Thrombosis of the brachial artery produces lameness, which 

 regularly recurs with work, and can, therefore, be easily recognised. 

 It is rare, but has several times been seen in horses. 



An old Percheron mare appeared lame on being rapidly trotted or worked 

 in a cart. At first there was only stiffness, but in about ten minutes both 

 fore-limbs began to tremble, and thereafter to give way, the animal threw 

 the head and neck violently upwards, and seemed doubtful which leg to 

 stand on ; the respiration and pulse were increased, and sometimes general 

 sweating followed, though the fore-limbs remained dry. These symptoms 

 disappeared after a quarter to half an hour's rest, but always recurred on 

 movement. Post-mortem examination showed thrombosis of both brachial 

 arteries, which were much thickened. 



Moller saw a similar case in a seven-year-old mare. When resting 

 she showed nothing whatever unusual, though careful examination 

 revealed hypertrophy of the heart. After ten minutes' trotting the mare 

 began to place the fore- feet abnormally far forward and outward and to 

 stumble. The off fore-limb was especially affected ; the toe often struck 

 the ground, causing the animal to stumble and fall ; on rising, the legs were 

 propped out and the muscles trembled, particularly the triceps. All these 

 symptoms disappeared after five to ten minutes' rest, to return again on 

 exertion. 



Many similar cases have been seen and verified by post-mortem. A 

 horse which suffered from obstruction of the femoral artery began to show 

 symptoms of radial thrombosis ; during movement, the radial symptoms 

 set in later than the femoral, but lasted longer, persisting for even half an 

 hour. Post-mortem showed thrombi in the arteria subclavia, arteria 

 axillaris, brachialis and radialis, and even in the metacarpal arteries. The 

 muscular coats were thickened, and the intima altered in character 

 (endoarteritis). 



Martin saw thrombosis of the axillary artery followed by gangrenous 



