270 VETERINARY HYGIENE 



recently infected animals which may not react to a first test leads 

 to a false sense of security and frequently to a second outbreak. 

 Too much emphasis cannot be laid upon the fact that a stable 

 cannot be considered to be free until a second test has failed to 

 show any reactors. In the case of colliery animals or any stud 

 into which a batch of newly purchased animals is to be introduced, 

 a first testing which has revealed a reactor or a doubtful reactor 

 should always be followed by a second testing after about six weeks, 

 and before the newly purchased animals are mixed with the others. 

 It need hardly be said that doubtful reactors should be kept rigidly 

 isolated from the apparently healthy. Having removed both 

 reactors and doubtful cases the premises must be thoroughly 

 cleansed and disinfected (see Disinfection). Special attention 

 should be paid to mangers, travisses, nose-bags, harness, especially 

 bridles, and stall fastenings. Sponges, rubbers and the like should 

 be burned. Mangers, buckets, drinking-troughs, carriage poles 

 and shafts must receive careful attention. As the bacillus is 

 readily destroyed by desiccation, &c., fresh air and light, especially 

 direct sunlight, are valuable aids in the eradication of the disease. 

 Horses coming from an infected stable should not drink from public 

 troughs until all danger of infection is passed. 



Animals which have presumably recovered from the disease, 

 as shown by non-reaction to mallein for several months, possess no 

 increased resistance to the B. mallei or its toxins (Nocard). A 

 method of vaccination has, however, been introduced by Marxer* 

 which depends upon the use of bacilli attenuated by urea and the 



resulting immunity is said to last about a year. 



? 

 I 



BOVINE CONTAGIOUS ABORTION. 



Bovine Contagious Abortion (bovine epizootic abortion) is a 

 contagious disease characterised by a chronic metritis due to a 

 specific micro-organism, the bacillus of contagious abortion, or 

 Bang's bacillus. The metritis is generally, but by no means in all 

 cases, followed by abortion of the foetus; and as a rule constitu- 

 tional disturbance is very slight. The disease is strictly contagious, 

 the causal organism being obligatory and incapable of multiplying 

 outside the bodies of diseased animals. The source of infection 

 therefore is always directly or indirectly a previous case. The 

 disease, which has been in existence in the British Isles for many 

 years, is now very widespread and probably the cause of greater 

 economic loss to cattle breeders than any other. In this respect 

 * Journ. Comp. Path., 1908, Vol. XXL, p. 269, Trans. 





