LAREDO, TEXAS — Fred Garza has been patrolling a piece of the Rio Grande for 16 years, usually riding solo on horseback, sometimes venturing to areas where his radio and cellphone have limited range.
But Garza isn't looking for drug smugglers, human traffickers or illegal immigrants. He's looking for stray livestock that might be carrying a tick with a deadly disease into the United States.
"If it doesn't have hooves, it's not our concern," Garza said.
Garza is a veteran of the 61-member U.S. Department of Agriculture "tick rider" force, which keeps watch over a 700-mile buffer zone along the Rio Grande from Brownsville to Del Rio.
They inspect both foreign strays and native ranch animals for the fever tick, a parasite eradicated in the U.S. 65 years ago that can transmit disease to cattle and could spread to the entire southeastern U.S. if not controlled.
Lately, the tick has managed to migrate beyond the 862-square-mile permanent quarantine zone, an area from which cattle can't be removed unless they are free of ticks.
The spread has forced the formation of three temporary quarantine zones totaling more than 1,100 square miles.
Bob Hillman, state veterinarian and executive director of the Texas Animal Health Commission, said officials were concerned that fever ticks might spread to other regions.
"They're not adept at dealing with fever ticks in other parts of the country," Hillman said.
Before cattle from any quarantine zone can be moved into a "free area," they must be "scratched," or inspected, for ticks.
On the ranch, that usually involves forcing four or five animals into a narrow chute, where their udders, flanks and other areas can be felt for ticks.
In the wild, it means cattle must be "apprehended" -- that's tick rider-speak for roped -- for a thorough check.
Tick fever can kill up to 90% of infected cattle, causing anemia, weight loss and bloody urine before death.