"As of Wednesday evening, infection has been confirmed only in El Paso County," said Dr. Bob Hillman, state veterinarian and executive director for the Texas Animal Health Commission.

Hillman said El Paso County has been quarantined by the TAHC, and the New Mexico Livestock Board has quarantined Luna, Dona Ana and Otero counties in New Mexico. By mid-afternoon, the U.S. Department of Agriculture is expected to have placed a federal quarantine on these counties, in addition to Hudspeth County in Texas.

The flock in El Paso County was destroyed earlier this week in an effort to keep the disease from spreading, Hillman said.

"However, the five counties quarantined in Texas and New Mexico are considered to be a trade area in which there is significant movement of birds and poultry," Hillman said.

"State and federal authority is being imposed so that disease surveillance, testing and diagnosis can be conducted. It is customary for the USDA to quarantine additional counties, in order to create a 'buffer zone' around an infected county. The END outbreak must be stopped before it spreads to other backyard, hobbyist or exhibition flocks, or to the commercial poultry industry," he added.

Hillman said the USDA provides fair market payment for birds that are destroyed during the outbreak.

Dr. John El-Attrache, assistant professor of veterinary pathobiology at the College of Veterinary Medicine at Texas A&M University, said the original disease introduction in California about six months ago came from the illegal importation of fighting gamecocks into eastern Los Angeles from Mexico.

As of early April, more than 3.5 million birds in southern California had been destroyed to stop the spread of END, according to the TAHC. This disease has affected the commercial egg-laying industry in southern California as well as non-commercial birds in two bordering states, El-Attrache said.

While END poses little threat to humans or the food supply, it typically causes severe illness and death in commercial poultry and gamecock flocks, and it also affects domesticated birds such as parrots and budgies.

Dr. Bruce Lawhorn, veterinarian with Texas Cooperative Extension and the College of Veterinary Medicine at Texas A&M, said symptoms of END are respiratory distress such as gasping and/or coughing; central nervous disorders such as depression, circling, paralysis, drooping wings and/or dragging legs; greenish diarrhea; swelling of the tissues around the neck and head; or a drop in egg production.

Death is almost certain; it's just a matter of the number of birds lost, he said. Also, death may be the first sign seen in some flocks with END.

If birds are vaccinated, the symptoms in commercial flocks may be less severe, with only a moderate death loss and reduction in egg production, Lawhorn said. The virus that causes END can be spread by carrier birds through respiratory discharges, feces or feathers.

The virus can survive several weeks in warm, humid weather, said Dr. Max Coats, TAHC assistant deputy director for animal health programs. In cold temperatures, it can remain alive indefinitely. Viral disinfectants, dry weather and sunshine, however, kill the disease.

The commercial poultry industry in Texas employs more than 11,000 people and generates annual cash receipts of more than $1.4 billion.

Dr. Alan Sams, head of the department of poultry science, said there is little commercial production of poultry in West Texas. Most of it is in the eastern and central regions of the state.

"Our primary concern is the movement of birds and people, which is now highly restricted by the animal health authorities," Sams said.

Since the disease must be reported to government animal health authorities, interstate commerce as well as international exports can be impacted, El-Attrache said.

Any unusual death losses or illness in flocks should be reported. In Texas, owners can call their veterinarians or the TAHC, which takes emergency calls 24 hours a day at (800) 550-8242.

e-mail: rsmith@primediabusiness.com