Biological Therapy 



125 



Calf Scour 



Calf Scour, also known as white scour, is essentially a 

 disease affecting calves during the first few weeks of life. 

 Although white-scour is seen in the young of all species, it 

 is most prevalent and of most economic importance in the 

 bovine. 



The disease, although prevalent in all parts of the coun- 

 try, has caused its greatest loss in the large dairy districts 

 where the mortality frequently reaches 90 to 100 per cent of 

 all calves born on farms where the disease is prevalent. 

 Many animals which might recover from calf scour, develop 

 pneumonia and die from this complication, thus enhancing 

 the need for the control of this disease. 



ETIOLOGY. Formerly considered a milk-borne dietary 

 disturbance, this disease is now known to be a bacterial in- 

 fection. While many organisms have at different times been 

 considered of etiological importance, scientists are now quite 

 generally agreed that B. coli is the primary invader, while 

 B. paracoli is closely associated as a secondary invader. 



The unusual prevalence of the disease in herds where 

 the animals are known to be affected with infectious abor- 

 tion, justifies the consideration of B. abortus as an etiological 

 factor. This possibility has been noted by Williams on sev- 

 eral occasions. Theobald Smith cites a case in which calf 

 scour was caused by the injection of B. abortus. Guinea pigs 

 were inoculated with small sections from a pneumonic area 

 of the infected calf and B. abortus in pure cultures was re- 

 covered from the guinea pigs after death. 



TRANSMISSION. The disease at times appears in new 

 localities in such a manner that we are justified in assuming 

 that B. coli and B. paracoli, ordinarily present in the in- 

 testinal tract or in the stables occupied by the infected ani- 

 mals, have in some manner developed unusual virulency. 

 The reverse may be the case and the disease follow any 

 condition which lowers the vitality of the calves. 



Infection once present in a stable is extremely difficult 

 of eradication; this for the reason that the contents of the 

 stable may harbor contaminated material or that the disease 

 may be constantly propagated by infected animals. Healthy 

 calves frequently become infected from eating contaminated 

 food, coming in contact with contaminated bedding ma- 



