488 BOARD OF AGRICULTURE. [Pub. Doc. 



The time to vaccinate depends largely upon circumstances. In 

 nearly every part of the country where blackleg is known there is 

 a distinct blackleg season, and the proper time to vaccinate is just 

 before the arrival of this season. Every practical ranchman and 

 farmer, as a rule, knows when to look for blackleg ; and, as the 

 disease may appear a little sooner or later, according to climatic 

 conditions, it is always better to vaccinate two or three weeks 

 before the beginning of the blackleg season. In some parts of the 

 Country it is not unusual that the calves commence dying when 

 only four months old, while in others they seldom become affected 

 until they are eight months old. It is, therefore, much a matter 

 of judgment when to vaccinate, and what should constitute the 

 minimum age at which the calves should be treated. 



Vaccination and castration should not be performed at the same 

 time. Castration is always a severe operation, and in some cases 

 decreases the vitality of the animals to such an extent as to make 

 them unable to resist the effect of the vaccination. The same 

 principle applies to all surgical operations (castration, spaying, 

 dehorning, etc.), as well as to those cases where the constitution 

 of the animal has been impaired from injuries external or internal. 



Ten days to two weeks should be allowed to pass after vaccina- 

 tion before any surgical operation is undertaken, and, if performed 

 before vaccination, ample time should be allowed for the part to 

 heal and for the animal to regain its lost strength. 



■'&•■ 



The Dose to be injected. 

 Animals one year old or over are injected with a full dost} of 

 vaccine, — that is, one cubic centimeter of the solution. Under 

 this age the dose may be reduced to one-half or three- fourths of a 

 full dose, according to the size and development of the animal. 

 Less than one-half a dose should never be injected. In determin- 

 ing the dose for each animal, more consideration should be given 

 to the size and development of the animal than to its exact age. 



How to operate. 



When the animals to be vaccinated are gentle, and accustomed 

 to being handled, vaccination may be performed on the standing 

 animal. Range cattle or other half-wild animals must be thrown 

 or secured, as in a dehorning chute. The most convenient place 

 to inoculate is on the side of the neck, just in front of the 

 shoulder, where the skin is loose and rather thin. If the animals 

 are secured in a dehorning chute, it is easier to vaccinate them on 

 the side of the chest, just behind the shoulder. 



