DYSENTERY IN CALVES. 211 



Causation. The exact cause of this form of dysentery in new-horn 

 calves has not yet heen identified, but the disease is undoubtedly a microbic 

 enteritis, and may even be a primary septicaemia of puerperal origin. 



For a very long time this dysentery was mistaken for simple 

 diarrhoea, though it exhibits neither the characteristics, course, nor 

 termination of the latter disease. 



The co-existence of epizootic abortion and dysentery in certain byres 

 has led some authors to believe that a connection exists between the 

 two diseases, and that the young are infected with dysentery at birth. 

 Evidently, intra-uterine infection is not exceptional, and it seems quite 

 natural that the new-born calf may equally suffer when the foetal 

 envelopes and fluids are infected before parturition. Epizootic abortion 

 is probably not the only disease which may produce this condition. 



The diagnosis is very simple. The course of the disease and its 

 rapid development prevent it from being mistaken for ordinary diarrhoea. 

 It is more difficult to distinguish from septicaemia of umbilical origin, 

 although this disease also has well-marked characteristics. 



The prognosis is not hopeful. Statistics show that almost all the 

 affected animals die, and that those exceptional cases which survive 

 remain puny and sickly. There is no economic advantage in attempting 

 to save them. 



The mothers of affected calves seldom show any sign of illness, 

 though the after-birth is often retained. 



Lesions. The macroscopic lesions are of very trifling importance 

 compared with the gravity of the disease. The digestive tract appears 

 congested throughout. The intestinal mucous membrane is moderately 

 swollen, but without gross lesions. The intestinal contents exhale a 

 sickly, foetid odour. The smaller vessels and capillaries forming the 

 peripheral vascular network appear distended, as in septicasmia. The 

 carcases putrefy with extreme rapidity. 



Curative treatment is very uncertain. Varying results have been 

 obtained with doses of 4 to 5 drams of slight purgatives like boro- 

 tartrate of potassium, sodium sulphate, and magnesium sulphate ; 

 small doses of intestinal antiseptics like salicylic acid, 15-grain doses of 

 salicylate of soda, 45 to 75 grains of carbolic acid, 2 jjer cent, carbolic 

 solution in doses of 7 to 12 drams ; 1 per cent. Lysol solution in doses 

 of 2 to 4 ounces; benzo-naphthol, lactic acid 45 to 75 grains, tar water, 

 lime water, etc. Although all these preparations, when carefully used, 

 generally give good results in the early stages of simple diarrhoea, 

 they appear to fail in dysentery of new-born calves. 



Prophylactic measures are more reliable. They consist : 



(1.) In scrupulous disinfection of the byres when the first case of 

 abortion occurs ; 



P 2 



