Running Rabid

Five years ago, rabies was rare in South Texas. Now nearly three hundred animals have died and the epidemic is not abating.

March 1993By Comments

The nature and nightmarish potential of the rabies outbreak dawned on South Texans in late 1988 and early 1989, when coyotes were seen trotting through the streets of Rio Grande City. The first of these wayward animals crossed U.S 183, the town’s busy main drag, and sat down in the yard of a highway patrolman. The officer promptly shot it.

The creature’s docile behavior was not atypical. The image of the rabid beast—staggering, snarling, drooling—is accurate but only half true; not all rabies is the furious type. Just as often, infected canids exhibit the lethargic and treacherous symptoms of “dumb” rabies. A few weeks after that first incident, another coyote sat watching cars go by a couple of blocks from the Starr County Courthouse. A resident shot it too.

Although rabies occurs regularly on the Mexican side of the river, the disease has been virtually unknown on the American side for nearly two decades. As of September 3, 1988, eighteen years had passed since the virus had last been detected in Starr and adjacent counties in any animals except bats. Since that date—when a sickly coyote entered a yard near the rural village of Rincon, menaced the owner, and fought with his two dogs while he ran for a gun—96 cases of animal rabies have been confirmed in Starr County alone. In a twelve-county area of South Texas, the number of cases is approaching 300 and shows no sign of slowing down.

The infected animals in Starr County have included a raccoon, a bobcat, a goat, and 3 domestic cats, but the overwhelming majority of cases have involved canids—27 coyotes, 60 dogs. The brush county outbreak has spread in a consistent pattern. In tiny ranching hamlets, there will be no sign of rabies; then, all at once, the areas are besieged. Rabid coyotes show up first. Then, after a lull of eighteen days, to ten months, unvaccinated dogs develop symptoms. Scattered north of Rio Grande City are Starr County’s principle ranching communities. Their names—El Sauz, La Gloria, Santa Elena, La Reforma—reflect the county’s dominant ethnicity. They are friendly little places with tidy homes and well-kept churches, perhaps a store and a school, cemeteries filled with the floral tributes that Hispanics bestow on the dead.

In March 1991 a wave of rabies passed through these enclaves in northern Starr County. The following August, on a ranch between El Sauz and La Gloria, a 55-year-old Hispanic woman fell ill and died of canine rabies. State health investigators could never prove that her tragedy was related to the coyote epidemic; incubation of the virus in humans can take more than a year, making cause and effect hard to pin down. But investigators became suspicious when they learned that the woman’s unvaccinated dog had recently died of unknown causes. A puppy that had played with the dog had later gotten a bone caught in its throat, and the woman had stuck her finger in the pup’s mouth, trying to dislodge the obstruction. Her husband swore that she was not bitten, but then, one doesn’t have to be. The virus can enter through a minor cut or an open sore. It can be transmitted through the mucus membranes of the eyes.

Unlike most viruses, which are blood-borne, rabies travels through the nervous system, reaching the spinal cord and then inching toward the brain. The gruesome vaccination ordeal of dozens of painful shots in the abdomen is an obsolete procedure; a newer and quite effective vaccine can be administered in a series of just six shots in the arm. But doctors have to realize that the shots are required, and rabies is notoriously hard to diagnose. Symptoms can include mental depression and restlessness, sore throat, fever, nausea, and stomach pains; the profile is easily mistaken for appendicitis or inflammation of the kidneys or pelvis. By the time lab testing confirms the disease, it is almost always too late. The patient can suffer seizures, hallucinations, uncontrollable excitement, and excruciatingly painful spasms in the neck and jaws. The spasms can be triggered by the slightest irritation. As a result, the patient is unable to drink, even though he may be consumed with thirst. Death from asphyxiation, exhaustion, or general paralysis usually follows in three to ten days. Rabies is a ghastly way to go.

North of the Starr County settlements, the chaparral stretches virtually unbroken for fifty miles before reaching the Jim Hogg county seat of Hebbronville. Late one afternoon in September 1991, a month after the death of the woman who handled the puppy, a three-year-old child was playing on her porch in Hebbronville. Inside the house, her mother heard the child suddenly begin to scream. She ran outside and saw blood and a nasty wound on her daughter’s back. This time the victim did not die, but the source of the bite was undisputable. In the yard was a rabid coyote that had come right up out of the brush.

Fortunately for humans and their domestic livestock and pets, the dozen or so known strains of rabies tend to be host specific. Dogs have dog rabies, raccoons have raccoon rabies. A particular strain can be transmitted to another species of mammal but not as readily as to the same species. In Texas, skunks are the creatures most often afflicted, accounting for about half of the more than four hundred positive tests recorded by the Texas Department of Health each year. Bats come in a far distant second. Like humans and cats, coyotes have not developed an endemic rabies strain and until now were rarely affected by rabies. The animal’s behavioral traits may help to account for that. Nimble and canny creatures, coyotes are hard to corner and have been clocked running 35 miles per hour. It is possible that they might just have a keen eye for sick animals acting crazy and have learned to avoid them.

The first crossover infection may have occurred long before the fall of 1988 and scores of miles from Starr County. Whenever it was, and wherever, a coyote contracted the strain of the rabies virus that U.S. scientists have named—with undiplomatic bluntness—Urban Mexican Dog. It is a particularly virulent strain of rabies, and once it jumped into the coyote population, a vicious cycle of coyote-to-dog transmission was established. In this part of the country, where vaccination of pets is not consistently practiced, the disease spread readily in populous areas.

Through 1990 the outbreak was confined to Starr and its downstream neighbor, Hidalgo County. In 1991 it abruptly leapt one hundred miles north of the Rio Grande. The outbreak has since spread through twelve of the state’s southernmost counties—roughly following a line from Corpus Christi to Laredo. In those counties, state health officials have now confirmed a total of 130 rabid coyotes and 149 dogs, only two of which had been vaccinated. Recently, a rabid coyote was killed on the beach near Port Aransas. As conditions now stand, there is no reason to believe the spread will stop short of the city limits of Victoria and San Antonio.

The present epidemic did not happen in a vacuum. Over the last several decades, coyotes have proliferated throughout North America as their chief natural rivals, wolves, have been eradicated. No habitat suits coyotes better than the brush country of South Texas, but as the incidence of rabies has grown, local residents have come to believe that the number of coyotes is way up. The past two years have brought unusually abundant rain and mild winters, and many species are doing well, among them cottontail rabbits, the primary prey of coyotes in the chaparral. With more rabbits for the adults to eat, more pups are likely to survive. Females are fertile at seven months and give birth to litters of six or seven pups.

But whether the coyote population is up or down, the incidence of rabies is definitely up. At the Texas Department of Health in Austin, Keith Clark, a Marble Falls rancher and veterinarian has been calling for emergency vaccination drives. A widely recognized authority on rabies, Clark says of the situation in South Texas, “We’re up against something that’s entirely new. Rabies is established in coyotes now. It’s not going to go away.”

“Here, hold this,” says Rio Grande City veterinarian Roberto Margo, placing a white plastic-foam container in the hands of a visitor. Margo turns to his paperwork with a slight smile. “It’s the head of a dog that died of rabies—probably.”

Packed in ice, the mongrel pup’s head will go by Greyhound bus freight to the Department of Health, where Keith Clark’s technicians will subsequently confirm it as the first case of rabies in Starr County in 1993.

In addition to operating a private practice, Margo serves as the Starr County veterinarian. His position sums up some of the problems facing the impoverished county. Rio Grande City (population 9,900) is the seat of Starr County but is unincorporated. Because of that, the city cannot effectively enforce measures such as mandatory pet-vaccination drives. All services, from water and sewage lines to public health and animal control, are administered by the county. But the county itself is so poor that it has no money to pay the county vet. Therefore, Margo does not earn a salary for his work. His situation has been frustrating.

Except for his years in college and the Air Force, Margo has always lived in Starr County—proudly chosen to live there—and he believes that the last thing his community needs is a reputation as the rabies capital of Texas. Margo is a part-time rancher, and he and his fellow ranchers harbor no great love for that folkloric trickster, the coyote. In addition to preying on rodents—which nobody minds—coyotes also kill the Spanish kid goats that local people raise to sell for cabrito. Coyotes also sneak up on cows that are temporarily immobilized by calving and kill their newborn. Starr County has a number of drip-irrigated farms; watermelons are a substantial cash crop. Coyotes are notorious for gnawing on them, prying open the rinds, and eating out the juicy hearts.

Margo remembers when the ranchers could buy strychnine in pharmacies and practice their own predator control. Congress and Richard Nixon outlawed that activity in 1972, but now some people are saying that it’s time to reverse the ban. They want to bring back strychnine or use the even more controversial and lethal poison known as 1080—sodium monofluoroacetate. In order to gain permission to use 1080, the county would have to persuade the Environmental Protection Agency to certify the coyote rabies outbreak as a federal health emergency. In Margo’s opinion, an emergency is precisely what the situation is. “We’re talking about human lives,” he says. “What are they waiting for?” He gazes out at the grayish-green chaparral that stretches north to the horizon. “How do they think it got to Hebbronville? Dogs? Cats?”

Slowly driving through a pasture that lies across the road from a subdivision of brick homes on Rio Grande City’s north side, an affable career civil servant named Martin Mendoza and his newly employed Starr County trapper, Rene Muñoz, are doing as much as the law allows to contain the rabies outbreak. Mendoza lives in Kingsville and is a district supervisor for the Animal Damage Control program of the U.S. Department of Agriculture. Mu&ñoz is a part-time rancher.

Mendoza is no ghoul. His job requires that coyotes be killed, but he avoids the use of steel traps and fence-line snares when he has an alternative. To spare the animals unnecessary agony, federal regulations mandate that the traps have to be checked as often as possible. “Nature takes care of overpopulation through starvation and disease,” Mendoza says. “Right now, the coyotes have lots to eat,” so that leaves disease. “Rabies is the bad luck of the draw.”

Rene Mu&ñoz pokes his Bronco along senderos (“trails”) that have been cut through the brush. He is checking on M-44 sodium cyanide devices, the primary means of coyote control in the area. The device is highly lethal, consisting of a short metal cylinder with a spring-loaded plunger inside. On top is a nub that can be baited with something the coyote finds irresistible—like a foul past of carrion and coyote urine. When the coyote gnaws on the nub and releases the spring, the plunger sends a spray of dry cyanide crystals into its mouth. The coyote is dead in a matter of seconds.

If landowners consent, federal trappers bury cyanide devices in the ground on their property, prominently marking them with red warning signs in English and Spanish. The M-44’s design is canine-specific so it does not pose a threat to other wild animals. Raptors and vultures are not strong enough to set of the guns with their beaks, and raccoons worry at the devices with their paws, which keeps them out of the line of fire even if they happen to trigger the device. Ocelots, jaguarondi, and other wild cats are spared by the advanced decomposition of the carrion bait. They like only fresh meat. Dogs, though, are easy victims, an incentive to owners to keep them penned up.

Stopping the Bronco to replenish the bait in a cyanide device, Mu&ñoz shows a visitor his pocket carton of amyl nitrate ampoules—the antidote for the poison, just in case. He talks about reading wind patterns and planting the M-44s just under a ridge, where coyotes like to sit and smell and watch. Smearing on the paste with an ice cream stick, Muñoz says, grinning, “I like to use jackrabbit. That coyote can hardly ever run one down, so he really likes the taste.”

Besides being a rancher, Muñoz used to work as a landman, a scout of promising oil leases, but then the bust hit. He needed a job, and this one came open. He converses with his boss in the easy way of border tejanos, switching back and forth from English to Spanish changing languages inmid-sentence.

Nearby, the bells of goats clank and tinkle. The sky is full of hawks and caracaras. The time is mid-January, and the mesquites are leafed out lime green. Soon the huisaches will burst aglow in delicate yellow flowers the size of dimes and it won’t be long before spring rain will ignite the cenzio’s purple blossoms. “Some people look at this and say there’s nothing here,” Muñoz observes. “Thorns and ugly old brush. But to me, this is beautiful.”

The same week that Muñoz is placing coyote bait around the countryside, Martin Mendoza drives to Laredo, where city-county health director Jerry Robinson has convened an informal but urgent session of the commissioners’ court. From Hebbronville, rabies has spread 25 miles northwest into Webb County, creating another rash of cases around the communities of Bruni, Oilton, and Mirando City. And now, suddenly fifteen miles north of Laredo, a rabid puppy is found to have exposed 19 humans to the disease. The city of more than 120,000 is almost surrounded by cases of rabies.

The commissioners and Robinson discuss bringing in a helicopter and a sharpshooter to hunt down coyotes from the air. Their aim is to create a coyote-free buffer zone in the brush outside of town and buy some time. Eventually though, they decide against it because the method is not only expensive but also has limited utility. “It’s effective,” says John Spruiell, one of the vets who sat in with Robinson and the commissioners, “but coyotes are too smart—it won’t work more than once.” Spruiell also doubts that much will come of Robinson’s demand for a strict ordinance enforcing pet licensing. “We’ve seen it all before,” he says. “The judges here just tell people that if they’ll go home and get their dogs vaccinated, they won’t have to pay the fines.”

Spruiell goes on to point out that dogs and coyotes are not the only species that need to be targeted. “I’ve got a client, a rancher, who was out working on a windmill,” he says. “Some of his cows and calves had come up close around. A coyote jumped out of the brush and ran right at those cattle. The mother cows went out to meet it and tromped it down real good. Because that rancher just happened to be on that windmill, he knew that he needed to get those cattle vaccinated. But what if he hadn’t seen that? Those cows are trained to come up and eat out of his hand. The next time he gets out of his pickup, his gentle Santa Gertrudis could come up at him like a Mexican fighting bull.”

It is hard to say which is more daunting—the logistics of dealing with the massive rabies outbreak, or the ethical and social issues that it has raised. At the meeting in Laredo, two other local veterinarians question the notion that healthy coyotes should be randomly sacrificed when humans can easily protect themselves by taking the responsibility for vaccinating their pets. But how realistic is it to expect people to suddenly respond when they have never done so before? Similarly, veterinarian Phyllis Volz-Creamer’s proposal of an oral vaccine for coyotes is greeted with a few discreet sighs. Webb County alone has 3,300 square miles of uninhabited land. Estimates of numbers of coyotes in the brush range from five to sixteen per square mile. The truth is, nobody really has a clue how many animals are out there or how they would reach them even if they did know.

Yet John Spruiell and Martin Mendoza both say an oral wildlife vaccine may be the only long-term solution to the problem. At Texas A&M’s college of veterinary medicine, Leon Russell, the faculty’s rabies expert, emphatically agrees. “An oral vaccine hasn’t been tried yet with coyotes,” he says. “But we need to be looking at Europe. The problem over there is with foxes—a very similar species. Ten years ago, West Germany, about the size of Oregon, was having more rabies cases than we see in the entire United States. They got on top of the problem by putting baits out by hand and helicopter, using a computer grid. They used chicken heads at first; now the bait’s a little more sophisticated. Switzerland also stopped fox rabies, and it didn’t bankrupt the government. If a vaccine can work in the Swiss Alps, open country is no reason not to try it in South Texas.”

He questions whether the control measures now under way will be effective. “Every experience we have with wildlife control suggests that the way we’re doing it now, trying to create these buffers, just won’t work,” Russell continues. When hunters and trappers have eradicated coyotes from a given area, he says, “the other coyotes sense there’s a vacuum in the habitat, and they come pouring back in to get the food. You can’t shoot or poison enough of them. It’s like trying to bail water out of a river.”

In rural Starr county, on the road from Rio Grande City to El Sauz, there is a turnoff at a small sign reading “Mirasoles Ranch.” The place is not far from the house where the woman fell sick from rabies two years ago. A few hundred yards down the dirt road are the remains of a community where nobody lives any more. Several of the abandoned homes are of forties frame construction; three others—roofless stone houses—were erected in a prior century. From them, coyote trapper Rene Muñoz salvaged hand-hewn mesquite windowsills that that been set in stucco by his ancestors. His cattle graze nearby.

As the sunset fades, the foliage, earth, and sky meld into a uniform gray. A great horned owl leaves a tree in ponderous flight. A cottontail hops across the road. And, as if you had called them up, coyotes erupt in a stammering yodel of howls, hoots, yips, and hollers. There are probably only two or three of them, but it seems like twenty. The sound is one of the most enchanting in nature, but things are different now. You smile that the creatures have noted your presence. But you stay safely in your car.

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