WSDA suspects Bovine TB in Grant County dairy cow

OLYMPIA - A cow from a Grant County dairy, suspected of having had bovine tuberculosis, was sent to slaughter earlier this month.

Bovine TB has not been seen in Washington cattle since 1988, according to the state Department of Agriculture. Agriculture officials are currently investigating the suspected case, stated WSDA communications director Hector Castro Friday. There is no immediate human concern with the suspected bovine TB case, according to state health officials. The meat from the cow was taken into isolation and destroyed.

The meat never entered the food stream, stated Castro.

There is no health concern with the milk produced at the dairy either, since the milk is pasteurized before being sold to consumers. The pasteurization process kills TB, he said.

According to the WSDA, the cow was pulled from a Grant County dairy herd and transported to a Cowlitz County facility for slaughter on Jan. 8. There, a U.S. Department of Agriculture food safety inspector noticed a suspicious lesion on the cow. A sample was sent to the National Veterinary Services Laboratory in Iowa for testing, The Iowa lab reported last week the sample was consistent with bovine TB.

According to Castro, the cow had only been at the Grant County dairy for about a year. The cow came from a herd previously housed at a dairy in Snohomish County, he said.

Because of that transfer, WSDA officials will also be working with the Snohomish County dairy during their investigation, stated Castro.

Castro stated WSDA officials will be making a visit to the Grant County dairy soon to test their herd of cows for TB. Although the dairy only uses about 500 cows for their milking operation, there are other cows in close proximity, he said.

As a result, an estimated 1,500 cows will have to be tested during their investigation, Castro stated.

Although the sample was reported as being consistent with bovine TB, Castro stated an additional test is being conducted in order to accurately diagnose the disease.

Those results are expected within the next six to eight weeks, he said. However, WSDA officials are still implementing safety precautions and working on tracing the source of the disease in the meantime.

"We are acting on the assumption that it is bovine TB, so we put safety measures in place," Castro explains.

WSDA officials have blocked the dairy from moving any cows during the investigation, he said. Bovine TB causes weight loss and a reduction of milk production in cows, Castro stated. Since it is a respiratory disease, bovine TB can be easily transmitted between cows in close proximity to each other. Although it is contagious, Castro explains bovine TB is slow-growing. When a case of bovine TB is detected in a cow, only about 1 to 4 percent of cattle in close proximity to it also get the disease, he said.

According to the state Department of Heath, a robust state and federal program for detecting the disease has helped keep Washington cattle TB-free.

"The good news is that the safety systems in place were effective in identifying this problem and preventing it from spreading," commented WSDA Director Dan Newhouse. WSDA did not identify the Grant County or the Snohomish County dairies.