276 DISEASES OP CATTLE. 



which serve to hold the part in position. In the fourth stage, ex- 

 tending to about the sixth month, the whole of the new structure is 

 converted into bone. In the fifth stage, extending to the end of the 

 first year, the callus is absorbed, being no longer necessarj'', and 

 the connection between the cavities of the tAvo bones is again 

 established. 



Common complications. — The process of union just described is 

 healthy and normal. Diseased conditions may at any time supervene 

 during the treatment and render the operation unsuccessful. In the 

 case of compound fracture, the open wound communicating with the 

 ends of the bones, a septic condition is liable to arise Avhich may be- 

 come so serious as to endanger the animal's life and bring about con- 

 ditions which in human surgery would indicate amputation. 

 Although that operation is not a general one in veterinary practice, 

 there is no reason why it should not be attempted as a last rer^ort, 

 particularly if the animal is valuable or is one whose existence is 

 necessary in order to perpetuate some valuable strain. Even in the 

 simplest form of fracture, if the splints or bandages are improperly 

 applied and the fractured bone left so loosely guarded that the 

 broken ends move one upon another, the formation of the calluses 

 previously described is liable to be interfered with, and in place of 

 a strong, rigid, and healthy union a formation of elastic cartilage is 

 the result. This false structure unites the broken ends of the bones 

 in such way that they move one upon another, depriving the bone of 

 its stability and usefuln^^ss. When once the healthy process of union 

 is interrupted in the manner just described, it is again established 

 with great difficulty. It no longer does any good to continue the 

 restraining power; in fact, the change of the temporary cartilage into 

 bone is more liable to be reestablished if the parts move violently upon 

 each other for a short time so as to set up and renew the process of 

 inflammation. Then if the restraint is again applied there is some 

 chance of union. In order so far as possible to avoid this danger, 

 care should be taken to see that the bandage fits closely and that it 

 is kept on till there is no longer any danger l)ut that a perfect union 

 has taken place. It is impossible to say at just what time the splints 

 or bandages can safely be removed. In a young and healthy animal 

 of quiet temperament, if the parts have been firmly held in position 

 throughout the whole time, from 30 to 40 days may be regarded as 

 reasonably safe. Under more unfavorable conditions as to age, 

 vitality, and restraint, the period would better be extended to 60 days, 

 if the general condition of the animal is such as to permit of so long 

 a continuance. After the appliance has been removed the animal 

 should be allowed to stand quiet for a few days, then be given very 

 gentle exercise, gi-adually increased for a week or 10 days, by which 

 time the patient will be so far recovered as to be placed in pasture. 



