436 PARASITISM AND DISEASE IN RUFFED GROUSE 



It has been pointed out that, during recent years, none of the pathological conditions en- 

 countered in the wild* have occurred in grouse hand-reared at the Research Center, and 

 none of the diseases which occasionally appear in captive grouse* have been found in wild 

 birds. It has been observed that the infestations with bird lice, when they do occur, are 

 heavier in the captive birds than in the wild ones. The lice involved, however, are not the 

 same species. The ones which occur on the hand-reared birds have pheasants as their ordi- 

 nary hosts. The heavier infestations are undoubtedly due to the lack of dusting facilities in 

 the cages. 



In the following sections, the important specific diseases of ruffed grouse in captivitv are 

 discussed. Three of these, "quail disease", blackhead and tuberculosis, make their primary 

 invasions in the digestive tract, though other organs may later be affected. Two, aspergillosis 

 and air-sac mites, are typically disorders of the respiratory tract and its appendages. One is 

 a nutritional disorder which affects the leg joints. 



It should be indicated that certain other pathological conditions appear in hand-reared 

 grouse, though no specific disease-producing organism is held to be responsible for their oc- 

 currence. For instance, congestion of the lungs or pneumonia, which is observed in young 

 chicks, generally follows exposure to over-heating or chilling. This may result from inade- 

 quate brooding facilities. There is also a condition in which urates, substances ordinarily 

 eliminated by the urinary system, are retained within the body and precipitate in the kid- 

 neys, liver and heart. Since this disorder can be produced experimentally by altering the diet 

 or environment, it is difficult to identify its cause. 



In the following sections, detailed descriptions of symptoms of the various diseases have 

 been omitted because of their undependability in the diagnosis of disease. Sick birds usu- 

 ally tend to present the same appearance and behavior when afflicted with any of a variety of 

 disorders. Positive identification of pathological conditions is best made by post-mortem ex- 

 amination of birds which died of disease or birds selected from pens where infection is sus- 

 pected. 



The several diseases which afflict hand-reared grouse may now be taken under specific 

 consideration. 



"Quail Disease" or Ulcerative enteritis 



Cause. The causative agent of this infection is still in doubt. Morley and Wetmore*" 

 isolated an organism which they believed to be the cause and named it Corynebacteriiim per- 

 dicium. Recently Bass'" reported that the true causative agent was an anaerobic organism. 

 Neither of these claims have been confirmed b\ nuraiit and noil"" wlm \mmc iiiuiblc to deter- 

 mine the cause of this disease. 



Nature of the Disease. The malady may be described as an acute contagious disease 

 tliai allacks the ceca and intestine of quail, grouse, chukars and turkeys. Outbreaks in the 

 two former species have occurred only in artificially propagated birds although Green and 

 ShilliiiL'cr'"" in Minnesota have re|)orted finding ulcerative <Mitcritis in a wild grouse. Post- 

 iniirtcni lesions may be entirclv lacking, especially in birds lliat die al llic lM-j;iniiing of an 

 cpi/odtic. Later, the dead birds arc found to have small hemorrhages on the surfaces of the 

 internal organs and extreme congestion of the intestinal and lacia nnicosa. In more advanced 

 cases, discrete round white necrotic areas 2 or .*? mm. in diameter are easily visible through 

 the intestinal wall. On the mucosal surface, these white areas are found to consist of raised 



With litii onr rirrption, aspcrgillotis. 



