Foot-and-mouth disease look-alike caused alarm at Mexican border

Oct 15, 2003 (CIDRAP News) – Mexico closed its border to livestock from the United States last week because of concern that a herd of US cattle bound for Mexico had foot-and-mouth disease, but the border was quickly reopened when the disease was found to be a relatively harmless look-alike.

Tests by the US Department of Agriculture (USDA) showed that the cattle had bovine papular stomatitis, according to Jim Rogers, a spokesman for the USDA's Animal and Plant Health Inspection Service. The condition is a mild viral disease of young cattle that causes mouth lesions resembling those of foot-and-mouth disease.

The cattle were being held at Nogales, Ariz., when Mexican inspectors noticed their lesions and became concerned, according to Rae Chornenky, legislative liaison with the Arizona Department of Agriculture in Phoenix. The border was closed late Thursday evening or early Friday, Oct 10, and was reopened about 2 p.m. Pacific time Friday, she told CIDRAP News.

Eight cattle, all but one under 10 months old, in a herd of 40 destined for Mexico had signs of illness, Chornenky said. The shipment came from Texas. Samples from the animals were sent for analysis to the USDA's Plum Island Animal Disease Center off Long Island in New York. (The Department of Homeland Security recently took over the Plum Island facility, but USDA continues to conduct research there.) Tests there identified the illness as bovine popular stomatitis, according to Rogers.

The cattle remained at Nogales today awaiting shipment to Mexico, Rogers reported. He called the border closure to livestock "rather unusual." He said a US Immigration Service official told him that the last time Mexico closed the border to US cattle and animal products was in 1996 because of vesicular stomatitis. The border was closed to poultry shipments in October 2002 because of exotic Newcastle disease, he added.

Bovine popular stomatitis is a mild viral infection of young cattle (2 weeks to 2 years old) that causes papules on the muzzle and inside the nostrils and mouth, Rogers reported by e-mail. Other clinical signs may include decreased appetite, excessive drooling, weight loss, and a slight fever. Caused by a parapoxvirus, the condition has been reported in the United States, Africa, Australia, New Zealand, Canada, and the United Kingdom. There is no treatment, and no control measures are implemented after diagnosis, but infected animals generally recover uneventfully, Rogers said.

Foot-and-mouth disease is a highly infectious viral disease of cattle, sheep, pigs, and wild ruminants. It has a fatality rate of about 60% in young animals and is of concern as a possible biological weapon because it can cause heavy economic losses.

See also:

CIDRAP overview of foot-and-mouth disease

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