570 Veterinary Medicine. 



digenous animal. Another important precaution is to select the 

 winter or cooler season for the operation rather than the summer. 



The animal which is to furnish the blood may be fixed in stocks, 

 or held with a bull ring, or it may be cast so that it can be kept 

 still. The hair is clipped or shaved from over the jugular vein 

 in the upper third of the neck and the surface is washed with soap 

 and water and with a five per cent, aqueous solution of carbolic 

 acid. A thick cord (}{ inch) is tied tightly around the back part 

 of the neck so as to compress and raise the jugulars. With a 

 sharp pointed bistuory sterilized by boiling, a small incision is 

 made through the skin, directly over the centre of the jugular 

 and a cannula and trochar yfrth inch in diameter and sterilized by 

 boiling, is passed obliquely upward through the coats of the vein 

 and the trochar withdrawn. The blood flows through the 

 cannula and is received in a sterilized (scalded) glass beaker. 

 The blood is stirred slowly with a sterilized glass rod until all the 

 fibrine has coagulated when the latter is lifted out and the remain- 

 ing liquid blood is ready for use. The blood is injected with a 

 hypodermic syringe which, with its nozzle, has been thoroughly 

 sterilized by boiling. The point selected for injection is usually 

 back of the scapula on the middle of the chest. The skin is 

 clipped or shaved, washed with soap, soaked in a five per cent, 

 carbolic acid solution, then pinched up, perforated with the point 

 of the bistuory, and with the nozzle of the syringe passed through 

 this wound the blood is injected into the subcutaneous connective 

 tissue. The slight wound may then be covered with tar or collo- 

 dion or merely left undressed. The mass of blood in the connec- 

 tive tissue may be diffused through its meshes by rubbing so as to 

 favor absorption. 



The dose of defibrinated blood employed is 5 cc. if from an 

 immunized northern ox, or 3 cc. or even 2^2 cc. if from an indi- 

 genous animal. The animal operated on should be in good health 

 and condition, well fed, and kept if possible in the shade, in a 

 cool stable, or under trees. 



In some respects it is preferable to operate on the animals be- 

 fore they are moved from the north or other nouinfected territory, 

 but as there is danger of infection in preserving and carrying the 

 blood, the treatment is more conveniently deferred until the animal 

 reaches the infected region where the blood can be had fresh. In 



