COCCIDIOSIS OP THE FOWL. 815 



COCCIDIOSIS OF THE FOWL. 



By H. H. CuBSON, M.E.C.V.S., Veterinary Kesearcli Officer, 



Grahamstown. 



This disease is very prevalent in tiie Cape Peninsula and probably 

 in other parts of tlie Union, and, as many poultry owners are not 

 even aware of its existence, and otiiers seem to regard it as a new 

 disease and are therefore ignorant of tlie ravages it may cause among 

 the'r birds, a brief description should prove useful, especially as the 

 disease is so important from an economic point of view. 



Among poultry breeders coccidiosis is often known as " white 

 diarrhoea " from the most common and most evident symptom. The 

 term '" white diarrhoea " is, however, somewhat misleading, for there 

 are other diseases which have as a common symptom the passage of 

 fluid-like feeces, and in many cases of coccidiosis the discharge from 

 the bowels is green or yellowish-green. 



Definition and Course of Disease. 



Coccidiosis is the name applied to a disease which is caused by a 

 parasite (iCoccidium or Eimeria avintn) belonging to the class of 

 organisms known as Protozoa. The main clinical symptom is an 

 enteritis or inflammation of the lining membrane of the intestines. 

 The course of the disease may be acute, as is generally the case in 

 chicks, or clirnnic in the chicks that survive an acute attack and in 

 older birds. In certain outbreaks many of the birds are found dead 

 before the disease has been noticed ; in other cases they are ill a few 

 days and then die. In adult fowls, however, in the more chronic 

 stages of the malady, they may linger for a few weeks and then 

 succumb . 



Cause of Disease. 



The causal parasite (Cocci dium or Eimeria avium) is found in 

 the intestine. The cysts that are passed out with the fseces are of a 

 regular ovoid or spherical shape, and can only be detected with the 

 aid of a microscope. 



The life-cycle of the parasite is somewhat complicated, involving 

 as it does more than half a dozen intermediate stages. The length 

 of the course, from the time the cysts become ingested with the food 

 or drinking water until a new generation of cysts is excreted in the 

 faeces, varies from eight to ten days. The cysts may then remain 

 alive in the crevices, etc.. of a poultry-run for at least twelve months 

 and during that time ag;iin become ingested, thus leinfecting the 

 birds. 



Symptoms. 



In the acute stage these, especially in birds that have unlimited 

 running" space, are often unobserved, but, if observed, they may be 

 described as follows : The onset is sudden and the chicks lose their 



