A few months back, Minnesota Assistant State Veterinarian Paul Anderson suggested it wouldn’t be surprising if the U.S. encounters a few cases of pseudorabies (PRV) in its bid to stay at zero and eradicate the disease.

His words proved prophetic. Minnesota has managed to stay PRV-free after cleaning up its first case in about a year in April, he says. But new cases were reported in Pennsylvania and Iowa in July.

The 200-head sow/boar herd tested positive in Crawford County in western Iowa has been depopulated, according to Lawrence Birchmeier, DVM, in charge of the PRV program for the Iowa Department of Agriculture. On a routine six-month test, five out of dozen 80-lb. pigs turned up positive. Circle testing in a 3-mile radius hasn’t turned up any additional positive animals.

In Pennsylvania, slaughter traceback of a cull sow revealed that one of five sow herds in a large multi-county operation was positive for PRV, reports Arnold Taft, DVM, USDA Animal and Plant Health Inspection Service National Animal Health Programs. In all, about 90% of the 700-sow herd tested positive. The operation feeds into three common nurseries. The pigs then go to 12 finishers, two of which have tested positive.

In less than a week, the one sow herd, all three nurseries and the two finishers in Lancaster and surrounding counties were depopulated, says Taft.

Taft assures that Pennsylvania, Stage V PRV-free status since June 2000, will retain its ranking as long as no further infection is found. Circle testing is being done in a 3-mile radius. The Pennsylvania situation shows that the virus doesn’t disappear overnight and that vaccination and surveillance are still needed," stresses Iowa’s Birchmeier.