The symptoms were all similar, and all ghastly. Within two to three days of infection the animal's temperature soars to 103�-106�. The horse becomes listless and depressed. Soon the blind staggers set in, and the horse stumbles about in circles or stands helplessly, often cross-legged. Within six to eight days, death occurs in 80% of the cases. Fortunately, human symptoms are milder, resembling influenza, and other nonequities seem immune. No human fatalities from VEE have been reported in the U.S.
Some officials blamed the erratic spread of the disease on hysteria. In Brownsville, panicky horse owners were seen loading their animals in trucks and heading north. "They thought they were escaping," said one vet, "but the horses were already infected, and they were just spreading it."
Dr. Gary Crouch, the Brownsville veterinarian who diagnosed the first U.S. cases, spoke of driving down a nearby road in the second week of July and seeing nine dead horses on the shoulder in one three-quarter-mile stretch. "They were dying all over the place," he said. "One man lost 12. The woman next door lost five out of six."
"We're unable to assess the number of dead," said Dr. Perrian Henry, federal coordinator at Harlingen, at the height of the epizootic. "I guess we've lost this battle, but we haven't lost the war." And the fight raged on.
On July 14 the USDA placed a federal quarantine on Texas. No horses or other equines would be allowed out of the state unless vaccinated at least 14 days prior to shipment. To this point VEE had been moving considerably faster than the wheels of the various bureaucracies seeking to contain it, and many Texans were critical of USDA efforts. By mid-July, when VEE was known to have been in this country for less than two weeks, Omohundro requested that Secretary of Agriculture Clifford M. Hardin declare a national emergency. Next day, Hardin agreed. The move was made, said Hardin's statement, "...to control and eradicate the disease wherever found," and in effect the campaign got a blank check to meet the emergency. The first step was to establish an east-west cordon sanitaire of vaccinated horses across Texas. Meantime, intensive spraying was begun and the states of Louisiana, Arkansas, Oklahoma and New Mexico shortly were added to the federal quarantine. A sixth state, Mississippi, was included later.
On July 18 Omohundro canceled a two-week family camping trip to Nova Scotia and flew to Texas to coordinate an anti-VEE task force of 80 men and women from 23 states that began moving into the sprawling Field Inn North motel outside Houston. Omohundro's defensive strategy depended on three weapons: the quarantines already imposed, mosquito spraying and vaccinations. He appointed men to administer each, and the USDA team went on 24-hour call, seven days a week.
To evaluate the effectiveness of their campaign, Omohundro's men tried to determine how many horses VEE was killing in Texas each day. But that proved impossible. To detect the presence of VEE, blood and tissue samples have to be taken while the horse is still alive or within half an hour after death. Otherwise the tests are inconclusive. Unfortunately, horse owners were seldom anxious to keep a dead horse around, or to call in a vet immediately after one had died. Many animals were simply buried, quickly, and so Omohundro's diagnosticians had to depend on luck or some rancher's inspiration. One call lured scientists on a two-hour drive at the end of which they found a horse that had been killed by a truck. Others were easier to find, but not all owners were cooperative. One Port Isabel rancher lost 30 head and was obviously miffed by the official inquiries. "All they can do is drive up and down the road asking how many dead horses have you got," he said. "I told one of 'em he should ask how many live horses I've got. I told him if another man asks me how many dead horses I have I'm going to whip him."
Texas politicians and newspapers were displaying some of the same impatience. U.S. Representative Eligio de la Garza said he had tried to get the USDA to fight the disease in June, before it reached Texas. And the Houston papers asked why the vaccinating wasn't started before the epizootic began. Dr. Omohundro responded to such questions succinctly. "I didn't make the decision when to start this program," he says. "I was just sent here to do a job."
One day after the Houston operation began, mosquito control planes were starting the largest aerial spraying operation in history. It covered the entire Texas coastline, part of Louisiana and a 130-mile stretch up the Rio Grande River, about eight million acres of potential mosquito breeding spots altogether. On the ground, meanwhile, a team of 26 entomologists was making mosquito counts—one of the methods was to walk into a swamp area (without benefit of insect repellent or special protective clothing) and see how many mosquitoes landed on you in two minutes. Only nine of the 26 men had been vaccinated against VEE. "We're not trying to kill all the mosquitoes," explained the chief entomologist at Houston, Dr. Robert Hoffman. "We're just buying time until they get 90% of the horses in Texas vaccinated."
It seemed a straightforward task, if not a simple one. Early estimates had put the number of horses there at 450,000, but it was soon apparent that someone had miscalculated. By the first week of this month Omohundro's men had already vaccinated 548,000 head, meaning the state had a phantom horse population of 100,000 or more. The trouble was statistical, of course. The last horse census taken in Texas was in 1960, and since then, as in most states, the horse population has more than doubled. At one point, therefore, Houston was estimating the figure to be more than a million, but later it was dropped to 700,000. And by this week the 90% vaccination level had been passed.