PULLMAN,WA/USA, July 12th (BIERMANN) – During a state fair for cattle, individual animals that were naturally infected with ovine herpes virus type 2 (OvHV-2), displayed severe disease and death. Most affected cows suffered from anorexia, signs of depression, diarrhea, fever, and respiratory distress that ultimately led to death, Dr. Dale A. Moore and associates write. The mean duration of clinical signs prior to death was six days (range, 1 to 26 days). The mean number of days betweent apparent exposure and death was 71 days (range, 46 to 139 days).

A total of 132 cattle were cohoused in one barn. From these, 19 died due to MCF. The diagnosis was confirmed by OvHV-2-specific PCR assay performed on tissue samples obtained from affected cattle. The veterinarians could demonstrate an association from distance from the center of the barn, however this was not significant. There was no association with distance from the center of sheep pens.

Dr. Moore and colleagues noted that MCF outbreaks in cattle are unusual, especially in association with livestock exhibitions. They recommend reporting and investigation of MCF cases. “Findings for this outbreak provided evidence to suggest that fair boards and veterinarians should re-examine biosecurity recommendations for livestock exhibitions”, they conclude.

References

• JAVMA 237(1):87-92