7|(i DIt. II. I!. I'AXI'IIAM ()\ AVIAX (()('( 'IIJIOSIS. |M;ivn. 



lIu'V call I'cacli oilier organs. l''iii-l her, t lie (leuudat ioii (if the 

 epithdiuni of the gut allows of easy entry of liacterial agents of 

 infection. 



In connection with tlie action of liactevia in the disease of 

 fowls known as '* wliite diairhcKa,"' there are two opposing views. 

 Morse (1908), working in America, has investi.^ated white 

 diarrlioca in fowls and other birds and alwa^'s found inte.stinal 

 coccidiosis. HaiUey (11)09), also working on the subject, found 

 not only intestinal but also hepatic coccidiosis in fowls suffering 

 fi'oni w-hite diarrluea. Morse notes the presence of bacteria in 

 the gut, and thinks that they may gain access to the .system 

 on account of the denudation of the gut e))ithelium. Rettger 

 (1909), on the other hand, considers that white diarrhoea is due 

 entirely to a bacterium, lUictcrudii scpticeiiild' (jdlllnaruni or 

 Bacteriuw pulloruvi. 



Probal)ly both of these conilic^ting views are right as far as they 

 go, but separately they may only partially explain the cause of 

 " white diarrhfca." ] )rs. Cobbett and Graham tSmith, of tlie Grouse 

 Di.sea.se Inquiry, have shown (1910) experimentally that Bacteria 

 niav be inoculated by means of coccidia, and find their way into the 

 internal organs probably by way of the portal vein. The agency 

 of parasitic worms and coccidia in causing lesions of the mucous 

 membrane through which harmful bacteria may enter, is of far- 

 ]-eaching importance and probably of wide application in tlie 

 elucidation of certain intestinal diseases. 



Morse's paper gives much valuable information regarding 

 treatment of coccidiosis and brief notes on intestinal coccidiosis of 

 various birds. Game birds other than grouse are susceptible to 

 coccidiosis, for M'Fadyean reported coccidiosis in pbeasants in 

 1893-4. At the time of correcting proofs of this article I am 

 engaged in investigating coccidiosis which is causing the death of 

 many young pheasants in various parts of England. 



The onset of sporogony of PJ. avium means either the recovery or 

 the death of the infected chick as a rule. When the oocysts pa.ss 

 out from the body of the host, the e})ithelium of the gut may be 

 able to recover itself, when the l)ird grarlually increases in weight 

 and makes partial or entire recovery. This recovery is sometimes 

 aitled l)y infiltration of connective tissue into the lesions. If, 

 however, the infection h.is been heavy, the epithelium cannot 

 regenerate itself and the bird liecomes exh.-iusted and dies. 



V. RklativI': uksistancf, of j:)ifi'i:i;i;m' Hi;i;i;r.s oi-' 

 Fowls axu Pioeoxs to Cocc'ij)iosis. 



Young chicks are far more susceptible to coccidiosis than :)dult 

 birds*. Very young fowl chicks (up to 8 days old) die in a few days 

 after l)eing fed with coccidian oocysts. Chicks first dosed willi 

 cysts when 14 days old do not succundi so ivadily ; they may li\e 



* 01(1 binls iiiny l)ecoin<' rhroiiics hikI thus intVct tlu' iikidis. In this comuctiau 

 infected foster mothers in phcMsniit-rcnrinir imiy he (hiniicnms. 



