22 



the temperature is high at the time of injection. In actual outbreaks, contact 

 horses, even when showing no clinical symptoms, but having a high initial- 

 temperature, dropping or remaining stationary after injection, should be conn:, 

 demnpd, especially when a local reaction occurs. ' ^^ 



In fact it may be laid down as a general rule that a typical local reactiortv^ 

 is proof positive of the existence of inlanders, even when no thermal disturb- 

 ance takes place. 



There is not, as a rule, much difficulty in distinguishing between a typical 

 'and a non-typical reaction. The former has been already described. In the; 

 latter the thermal rise seldom exceeds 2°, a«d reaches its greatest height at or 

 before the 12th hour, returning to normal before, the 20th hour. 



The Swelling, when circular, rarely exceeds three inches 'in diameter. It 

 is , only slightly painful, is quite superficial, soft and moveable, does not ' 

 increase after the 8thi hour, and is rapidly absorbed during the course of the 

 second day. It never affects the action of the muscles, nor does it cause lame- 

 ness. Sometimes a fluctuating dependent swelling of considerable size follows 

 a careless or unskillful injection, but this, as a rule, is absorbed rapidly during 

 the first 24 hours. , ' ' ! 



' ' With ordinary precautions sieptic infection seldom takes place, an-d abscess 

 formationi'S rare except irf typical reactors, when it is not uncommon. Occas- 

 ionally considerable swelling, sometime,s accompanied by a thermal rise, will 

 occur in horses sufiferLng from influenza and similar affection^. Such so-called 

 reactions are not typical, and should not be ascribed to the action of Mallein, 

 but to the already existiiig febrile condition of the animal. 



Cases sometimes occur in which, at the end of 24 hours after injection, . 

 neither thermal nor local conditions are sufficiently definite to Enable the 

 veterinarian tb reach a decision. In these circumstances the animal should be 

 kept under close' observation for a further period of 24 hours, when, if it is 

 diseased, the increased swelling and marked lameness which almost invariably 

 follow will remove any possible doubt. Suspected cases which have failed to • 

 give a decided reaction will not unfrequently develop clinical symptoms if 

 put to hard work immediately after being tested. 



Reaction, both thermal and local, but especially the latter, is not as well' 

 marked in mules as in horses, but as in the former acute symptoms are more 

 likely to develop early in the course of the disease, the risk from latent cases. 

 is less serious. 



It may be laid down as a general rule that while an apparent improvement 



in health and condition may, and frequently does, follow the application of 



, the test in mild or incipient cases, the effects of Mallein on animals in advanced 



stages of the disease are invariably bad, and that the testing of such cases 



hastens a fatal termination. ' * 



L,ocal reactions are more pronounced in hot , weather than when the 

 atmospheric conditions are moderate. In connection with this statement I 



