Sage Grouse Coccidiosis N o t Transmissible to Chickens R A L P H F.
HONESS
Wyoming Agricultural Experiment Station1 (Received for publication May 12, 1942)
I
viable oocysts from diseased sage grouse to the domestic chicken. Coccidial oocysts from sick birds were sporulated in 2 percent dichromate solution, washed, and fed to two breeds, White Leghorn and Plymouth Rock, varying in age from four weeks to five months. The experimental birds were isolated in cages with screen bottoms. Cross infections were tried for three consecutive years using oocysts collected from sage grouse in various areas. The number of chickens in the experimental groups were 4, 7, 16, and 22. Most of the birds received only one feeding of viable oocysts. Fecal examinations were begun on the fourth day and continued for 7 to 10 days. However, the experimental birds were, in most cases, kept under observation seven or eight days longer. Not a single case of coccidiosis developed in either the experimental birds or in the controls. Two groups of experimental birds were later fed viable oocysts from mixed infections in the domestic chicken. Nearly all of them developed severe coccidiosis and many of them succumbed. It may be safely concluded that coccidiosis is not carried to domestic chickens by the sage grouse, and it would seem probable that the infection in the sage grouse is not brought about by contact with infected domestic birds.
CROSS INFECTION EXPERIMENTS
A satisfactory method of rearing sage grouse in captivity has not been developed, and consequently the cross infection experiments were confined to the feeding of 1
Published by permission of the Director.
REFERENCES
Lee, M. A., and L. H. Scrivner, 1936. Wyoming Extension Service Circular No. 32. Revised. Simon, Felix, 1939. Eimeria centrocerci n. sp. ,Du Centrocercus urophasianus (coq du Bruyere), Annales de. Par. Hum, et Comp. 17:137.
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N THE fall of 1932 an outbreak of coccidiosis occurred among the sage grouse, Centrocercus urophasianus (Bonapart), on the Sweetwater River, Fremont County, Wyoming. This outbreak began on a ranch where the birds had been protected from hunting and consequently intermingled freely with the domesticated chickens on the ranch. Subsequent outbreaks occurred among sage grouse on or adjacent to ranches where domestic chickens were kept, but were not confined to such areas. Lee and Scrivner (1936) found coccidiosis to be one of the common diseases of chickens in Wyoming. It is highly infectious and causes considerable loss. Simon (1939) made a limited taxonomic study of the species of Eimeria infecting the sage grouse. He concluded there were two species present, Eimeria angusta Allen 1934 and a new species described as Eimeria centrocerci. Later studies have indicated there may be more than two species but this is of no practical importance insofar as cross infection is concerned. With but few exceptions all species of birds have their respective species of coccidia. Since, however, a few exceptions do exist, it was deemed advisable to try experimental cross infections between the domestic chicken and the sage grouse.