News Release
Texas Animal Health Commission
Box l2966 * Austin, Texas 78711 * (800) 550-8242 * FAX (512) 719-0719
Bob Hillman, DVM * Executive Director
For info, contact Carla Everett, information officer, at 1-800-550-8242,
ext. 710, or ceverett@...

By Carla Everett
For immediate release---

Stakes High in Fight Against the Cattle Fever Tick;
Pest Could Spread Coast-to-Coast

Livestock health officials say it could cost upwards of $13 million and
take as long as two years to stop an incursion of fever ticks into the
formerly fever tick free areas of five counties along the Texas-Mexico
border. The fever tick, less than a 1/8-inch long, is capable of carrying
and transmitting ‘babesia,’ a blood parasite deadly to cattle.

“For most of the country, the fever tick has been pushed out of sight, out
of mind, since the 1940s. This tick, however, is capable of transmitting a
foreign animal disease and it’s sitting in our backyard,” said Dr. Bob
Hillman, Texas’ state veterinarian and executive director of the Texas
Animal Health Commission (TAHC), the state’s livestock and poultry health
regulatory agency.

“If we do not stop it, the fever tick could spread from coast to coast,
except the arid lands of New Mexico and Arizona, and as far north as
Washington D.C.,” stressed Dr. Hillman. “As the tick spreads, so will the
need for personnel and resources. Win the battle along the Rio Grande in
Texas, and other states won’t have to fight the war.”

The TAHC has placed temporary fever tick quarantines on 1116.3 square miles
in five Texas border counties, including parts of Starr and Zapata
counties, and a contiguous area encompassing parts of Maverick, Dimmit and
Webb Counties. In addition, an 852-square mile permanent quarantine zone
butts up against the Rio Grande from Del Rio to Brownsville and is under
the management of the U.S. Department of Agriculture’s 60-person Fever Tick
Force.

The USDA, which is adding up to 30 temporary tick inspectors, and the TAHC,
which has detailed inspectors to south Texas on a rotating basis, are
working with ranchers to locate, ‘corral’ and eradicate the tick. In this
area about the size of Delaware, all cattle, horses, penned deer, llamas,
camels and any other species that can host the tick are being manually
inspected –or “scratched”--by TAHC or USDA inspectors.

If animals in these quarantined areas are moved from their premises,
they’ll undergo another “scratch” inspection, then be dipped or sprayed,
and permitted for movement. Because horses can give ticks a lift, these
animals are put under 14-day inspections and treatment, if they’re moved
routinely from their home base.

When fever tick-infested livestock are detected, the premises are
quarantined for six to nine months. As of early October, this included at
least 25 premises in the temporary quarantine areas and about 56 premises
in the permanent quarantine zone.

Cattle remaining on tick-infested premises must be inspected and dipped
every 14 days or treated with doramectin every 28 days. Alternatively, the
animals may be moved to a new site, but only after undergoing two
consecutive tick-free inspections and dippings. A movement permit then is
issued, and the cattle must be transported immediately.

“The USDA has made $340,000 available for immediate fever tick needs in
south Texas, and the state legislature granted the TAHC an extra $150,000
to purchase additional Co-Ral, the acaracide used for dipping vats and in
spray rigs,” Dr. Hillman said. He reported that a USDA assessment
concluded that to eliminate fever ticks from the temporary preventive
quarantine areas, at least $13 million was needed to hire additional
personnel, repair or replace worn out portable tick dipping equipment,
purchase new spray rigs and supplies, and procure other essential equipment.

“To get a handle on potential fever tick spread, the TAHC field staff also
is tracing the movement of cattle from infested premises in the temporary
quarantine area within the past year,” Dr. Hillman noted. So far, this has
involved nearly 800 animals, of which about 459 have been located,
inspected and found to be fever tick-free. Some were found in Kansas or
Texas Panhandle feed yards, and others were scattered across the state and
to two other states.

“Many of these animals had been moved as calves without any identification,
except the livestock market back tag, or clearly defined destination,” he
said. “This slows down our work, but we don’t give up until all avenues are
exhausted.”

“The fever tick, by itself, will not cause disease. However, cattle tick
fever is imminent if the fever tick is carrying babesia, and transmits it
to cattle that are ‘naïve,’ meaning they have no resistance to the organism
that quickly breaks down red blood cells,” said Dr. Hillman. “There are
two potential scenarios with fever ticks that keep the TAHC, the Tick Force
and border ranchers awake at night.”

The first scenario, explained Dr. Hillman, involves Mexico, where fever
ticks and babesia have not been eradicated. Young calves there may be
exposed to the babesia, survive the disease and develop immunity, but
continue to carry the organism.

“Even if Mexican feeder cattle carry babesia, they will not cause a disease
problem ­ unless there is fever tick involvement,” said Dr. Hillman,
setting the scene for the scenario. “Mexican-origin feeder cattle enter
the U.S. under strict USDA fever tick inspection and dipping requirements.
To keep them away from fever ticks, the TAHC requires Mexican-imported
cattle to have an “M” branded on their hip and prohibits these animals from
being maintained in the permanent quarantine zone.”

“If fever ticks are moved to sites where Mexican feeder cattle are
pastured, the pests may pick up babesia. The babesia infected female tick
transmits the disease to the next generation of fever ticks. Only one
element then would be missing from the dangerous disease equation ­ U.S.
cattle with no immunity to the babesia,” noted Dr. Hillman. “If native US
cattle, which are susceptible to babesiosis or ‘cattle tick fever,’ are
infested with babesia-infected fever ticks, then disease transmission to
the native cattle will occur. Most likely, this will cause significant
death loss of native cattle. It’s crucial to keep the fever tick pushed
beyond the border, and support and fund surveillance activities in the
permanent fever tick quarantine zone.”

Dr. Hillman said the second scenario involves wildlife as effective
alternative hosts and sources for movement of ticks into Texas from Mexico
and from the permanent quarantine zone to the free area of Texas. For once,
noted Dr. Hillman, the beleaguered feral (wild) hog is not implicated.
Fever ticks have not acclimated to swine, goats, sheep or dogs. On the
other hand, elk, white-tailed deer, nilgai and red deer, serve as effective
hosts for fever ticks, but are not affected by babesia.

“Free-ranging cervids do not respect national borders, shallow rivers, low
fences, quarantines, or permits for movement,” he said. “Wildlife hosts
may crisscross the Rio Grande, hauling in fever ticks. Right now, wildlife
presents the greatest risk for fever tick movement.”

In spring 2007, more than 30 nilgai were depopulated in the Lower Rio
Grande Valley National Wildlife Refuge, due to fever tick infestation.
Twenty-eight of the 42 free-ranging white-tailed deer that were trapped and
examined this year also were “ticky.”

“Treating wildlife is a tricky proposition, because current methods are
limited to feeding cervids ivormectin-treated corn or drawing them to
‘four-poster’ stations where they rub against pyrethrin-treated posts,
which transfers the chemical,” he said. “Ivormectin use requires a 60-day
withholding period prior to slaughter or harvest, so wildlife feeding
treatments will be delayed until hunting season ends.”

In the meantime, the USDA or TAHC must inspect, treat and permit the
movement of hides from deer or exotic hoof stock harvested on tick-infested
or exposed premises. (Meat may be moved without inspection.) To avoid the
possibility of transporting fever ticks, ranchers and hunters are urged to
practice good sanitary measures when leaving a ranch. Brush off clothing
to dislodge any ticks that may be on the fabric. Clean off boots and shake
out jackets or items that have been on the ground.

“The fever tick is not a human health threat,” said Dr. Hillman. “But be
careful. Don’t transport ticks to new sites. Getting and keeping the fever
tick out of Texas and the U.S. is critical for disease control and our
continued ability to move livestock without restrictions.”

“If we are ultimately to be successful in our battle against the fever tick
and ’cattle tick fever,’ we must eliminate the current fever tick
incursions in the free areas of Texas, then push the pest back into
Mexico. To accomplish this, we must acquire resources necessary to fulfill
the long-range fever tick eradication plan, fund research and develop
additional treatment products and methods. We also must aid our Mexican
neighbors in their fight against the fever tick and ’cattle tick fever,’”
concluded Dr. Hillman.


---30--