PREVENTIVE MEDICINE 317 



dium cuniculi. Probably more work has been done with this 

 coccidium than with any other, chiefly for the reason that the disease 

 in rabbits is very widespread, occurring both among domesticated 

 and wild rabbits, but especially among the former. 



Coccidiosis of Cattle (red dysentery). Due to Coccidium ziirni. 

 The etiological significance of coccidia with regard to this disease 

 of cattle was first pointed out in 1892 by Zschokke,* but the para- 

 site had been previously noted by Ziirn in 1878. In Great Britain 

 the first cases were recorded by Gairf in 1898 and later by the 

 author J in north Devon in 1913. It is also known to occur in Corn- 

 wall and in Ireland, and is probably not uncommon in other parts 

 of the country. The disease usually attacks cattle when from 6 

 months to 2 years of age, though in Gair's cases adult milch cows 

 were also attacked. The author has not seen it in cattle which were 

 more than 18 months of age, even though such adult cattle were 

 grazing in the same fields as the affected animals, neither could 

 coccidia be found in their f?eces. The course of the disease is vari- 

 able. Zschokke, in Switzerland, found that sometimes all symptoms 

 disappeared in 5 to 10 days, though sometimes the disease lasted for 

 weeks and was accompanied by great emaciation. The incubation 

 period has been fixed by Degoix at from 1 to 2 months, which was 

 the time elapsing between the turning out of healthy animals into in- 

 fected pastures and the moment at which symptoms appeared. In 

 experimental cases the period of incubation has been found to be 

 about 3 weeks. Outbreaks sometimes reappear year after year on 

 certain pastures (Degoix). The disease is essentially a summer one, 

 cases chiefly occurring in July and August and, to a much less extent, 

 in September, though Gair, on farms where it reappeared, has 

 noticed it as early as April. It is especially to be met with in low- 

 lying damp pastures. The method of infection is by ingestion. 

 Though it is easy to understand why the disease spreads among 

 cattle in the same herd or in the same district, it is difficult in 

 certain instances to say how the disease arises. The purchase of 

 infected stock is doubtless a common method, but the author has 

 been able to exclude this means and has not been able to trace the 

 origin of certain outbreaks. A more careful routine examination 

 of the faeces of diarrhceic bovine patients might reveal unsuspected 

 cases of the disease, and thus throw some light on its transmission. 

 The mortality from the disease is very variable. Zschokke noted 

 *Journ. Comp. Path., Vol. V., p. 101, Trans, 

 t/owrn. Comp. Path., 1898, Vol. XL, p. 171. 



t Vet. Rec., 1913, Vol. XXVI., p. 71. 

 %Journ. Comp. Path., 1904, Vol. XVII., p. 91. 



