BOTULISM 



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V DIAGNOSIS OF PHEASANT BOTULISMpProctor, S. J., Cassidy, D. R. and Harrington, R. (Project Report) 



Summary 



Botulism in pheasants caused by the ingestion of fly maggots containing .type C botulinum toxin was 

 diagnosed. Diagnosis was based upon finding the source of toxin and demonstrating its presence in serum of acutely 

 intoxicated pheasants. 



Introduction 



Animal botulism is initiated when feed containing botulinum toxin is ingested. Clostridial spores usually pass 

 through the digestive tract without harming animals. Culturing Clostridium botulinum from gastrointestinal contents 

 does not constitute a basis for the diagnosis of botulism. Demonstration of botulinum toxins in animal feed or 

 intestinal contents is a better index of intoxication, but a definitive diagnosis depends upon the demonstration of 

 botulinum toxins in serum or tissue samples. 



Pheasant botulism on game bird farms presents some unique features. Environmental conditions such as 

 crowding, dense cover in pens, fly larvae, ubiquity of C. botulinum spores, weather conditions, and the pheasants' 

 avid seeking of larvae and worms all contribute to botulism epornitics on game farms. Pheasants are susceptible to 

 botulinum toxins types A, C, and E. They are relatively resistant to type B (3, 6). 1 



The following report concerns the diagnosis of botulism on a game bird farm. 



Case Report 



In 1969 and 1970, from August to September, severe losses were experienced in a group of 7,000 Chinese 

 ring-necked pheasants, Phasianus colchicus torquatus, on a game bird farm in Kansas. Progressive ataxia, weakness, 

 "walking" on wings and flaccid paralysis were noted in the pheasants. No significant gross or microscopic lesions 

 were observed. 



Severe losses were again experienced in September 1971, on the same game farm. Clinical signs were 

 progressive flaccid paralysis and acute death. Affected pheasants were found lying on their sides or sternums. A 

 dense growth of grass, milo, and weeds, which hid dead bird carcasses, was present in each pen. Automatic waterers 

 and turkey feeders were present in each pen; however, feeder space was not adequate. 



Several flv-blown pheasant carcasses were collected from the pens, placed on dry ice. and transported to the 

 laboratory. Blood was collected from 10 acutely sick birds to obtain serum which was then frozen and transported 

 to the laboratory. Necropsies were performed on the sick birds and tissues collected for histologic examination. 

 Increased pericardial fluid was the only consistent necropsy lesion. 



Laboratory Procedures and Results 



Fifty blowfly larvae from two pheasant carcasses were macerated with a mortar and pestle and suspended in 

 50 ml. of phosphate-buffered saline which was centrifuged at 5000 r.p.m. for 5 minutes. Mouse neutralization tests 

 were performed on the supernatant and 10 pheasant serums (1). Type C botulinum toxin was found in the 

 supernatant and serum. Type C botulinum antitoxin or heat neutralized the lethal toxin. 



Numbers in parentheses refer to References at the end of this report. 

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