BOTULISM IN CATTLE 73 



and it is suggested that these organisms may apparently be 

 associated with the disease or may serve as causal agents in a 

 secondary etiologic capacity, since experimental evidence in 

 animals, to demonstrate the primary toxic character of certain 

 organisms of this class per se, is unconvincing. If deductions 

 are to be drawn at this time from a review of the literature and 

 experimental evidence at hand in our studies, it appears that the 

 moulds encountered are probably not of widespread primary 

 importance in the toxemic-like disease of animals in ciuestion, 

 as it occurs throughout the Mississippi Valley. 



The writers have observed outbreaks of so-called forage 

 poisoning in equines which were quite definitely related to the 

 consumption of feed containing B. botidinns toxin. Susceptible 

 animals (horses and mules) could be protected against the toxin 

 in the feed by a prophylactic injection of botulinus antitoxin 

 (Graham and Brueckner (1919) ). The relation of B. botidinus of 

 human origin (type B), was also noted by immunologic tests, 

 while Burke of California has more recently incriminated B. 

 botulimis (type A) in forage poisoning in horses (Burke, 1919). 

 This strain has not been encountered to date in outbreaks of 

 equine botulism coming under our observation. 



RESISTANCE OF BOVINES TO BOTULINUS TOXIN 



Following preliminary field observations of bovine forage 

 poisoning in Illinois, Rusk and Grindley state 



The results of these investigations seem to indicate that most cattle 

 are not so susceptible to forage poisoning as are horses and mules, and 

 that contaminated corn silage, and possibly other animal feeds which 

 are unsafe or fatal to horses, may be fed with less danger to cattle 

 . . . . however, the evidence from many outbreaks leads the 

 authors to suspect that some cattle are more susceptible than others 

 and that damaged or otherwise contaminated corn silage, or possibly 

 other feeds, may in some instances produce fatal results in cattle fol- 

 lowing ingestion. 



Cattle have been fed rations spontaneously contaminated with 

 botulinus toxin (type B) without manifest sjanptoms of illness 

 other than loss of body weight, and mature cattle have con- 



