824 DISEASES OF THE METACARPUS. 



Treatment. Id the chronic form blisters or firing may be tried, 

 but are rarely successful. Nor is compression or massage of much 

 service. If thought desirable, bandages may be firmly applied 

 extending above and below the joint, and changed from time to 

 time. Better results, however, attend the injection of weak iodine, 

 sublimate or carbolic solution after the synovial sa$ has been emptied 

 with a fine trocar or aspirating needle. When the sheath is wounded, 

 every effort must be made to render the parts aseptic, and after 

 inserting sutures, a dressing must be applied. In purulent synovitis, 

 the bursa may be frequently rinsed out with antiseptics, though 

 such treatment is seldom successful. The horse must, of course, 

 be slung. Where an antiseptic dressing cannot be applied, the parts 

 may be permanently irrigated with boiled water or antiseptics. If 

 performed cautiously, there is little danger in puncturing the 

 swelling and giving exit to contents, though the gain is slight, but 

 particular care should be taken not to make large incisions, unless 

 they can be kept aseptic, as purulent synovitis generally results, 

 and frequently proves incurable. 



D. DISEASES OF THE METACARPUS. 



The metacarpus in solipeds consists of the cannon bone, and the two 

 small metacarpals. The tendons of the extensors of the digit cover its anterior 

 surface ; behind it lie the suspensory ligament and the two flexor tendons, 

 to some extent enclosed by the two small metacarpals. The whole 

 metacarpus is covered with a tensely- stretched skin, which is only slightly 

 movable on the underlying parts. 



In ruminants the two cannon bones become united soon after birth and 

 form only one bone, on whose posterior and outer surface lies the rudimen- 

 tary small metacarpal, which is articulated to the fused metacarpal by 

 means of a small joint. This rudimentary metacarpal does not contribute 

 to the formation of the knee. 



In swine the two middle or true cannon bones form, with the external 

 or false metacarpals, the metacarpus. Carnivorous animals possess five 

 metacarpals, those of the third and fourth toes being the strongest. 



I.— FRACTURES OF THE METACARPUS. 



In solipeds fracture often involves the three bones of the meta- 

 carpus. The small metacarpals seldom escape, still less frequently 

 are they alone fractured. In other animals, particularly in carnivora, 

 a single bone may be injured, though it is more common for several 

 to be broken at one time. Owing to the thin covering of soft parts 

 the closely-applied skin is readily perforated by fragments ; 

 compound fractures are thus produced, which unite with great 

 difficulty. 



