Outbreak of malignant catarrhal fever among cattle associated with a state livestock exhibition.
METHODS
Severe disease and death were identified in cattle exhibited at a state fair that were naturally infected with ovine herpesvirus type 2 (OvHV-2).


RESULTS
Most affected cattle had anorexia, signs of depression, diarrhea, fever, and respiratory distress ultimately leading to death. Mean duration of clinical signs prior to death was 6 days (range, 1 to 26 days). Mean number of days between apparent exposure and death was 71 days (range, 46 to 139 days).


RESULTS
19 of 132 cattle cohoused in 1 barn died of malignant catarrhal fever (MCF). The diagnosis of sheep-associated MCF was confirmed on the basis of results of an OvHV-2-specific PCR assay performed on tissue samples obtained from affected cattle. The disease was associated but not significantly with distance from the center of the barn and was not associated with distance from the center of the sheep pens.


CONCLUSIONS
Outbreaks of MCF in cattle are unusual, particularly in association with livestock exhibitions. Because the clinical signs may be similar to those of some transboundary diseases, cases of MCF should be reported and investigated. Findings for this outbreak provided evidence to suggest that fair boards and veterinarians should reexamine biosecurity recommendations for livestock exhibitions.
Moore
Dale A
DA
Department of Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA. damoore@vetmed.wsu.edu
Kohrs
Paul
P
Baszler
Timothy
T
Faux
Cynthia
C
Sathre
Peter
P
Wenz
John R
JR
Eldridge
Leonard
L
Li
Hong
H
D000818:Animals; D000829:Animals, Domestic; D002417:Cattle; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D008297:Male; D008304:Malignant Catarrh / Q000453:epidemiology* / Q000401:mortality; D014861:Washington / Q000453:epidemiology