A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: 6 Jul 2009
Source: Texas Animal Health Commission, news release [edited]
Ranchers, Regulators Weary from Cattle Fever Tick War
-----------------------------------------------------
Texas animal health officials have cast another wide net in the battle
to eradicate cattle fever ticks in South Texas. The Texas Animal
Health Commission (TAHC) has temporarily quarantined 152 716 acres in
Starr and Hidalgo counties. In nearby Zapata County, 5-mile quarantine
perimeters are being drawn around fever-tick infested pastures. A
foreign pest, the cattle fever tick has the capability to carry and
transmit _Babesia_ spp, a blood parasite that can kill adult cattle.
Although it prefers cattle, the fever tick can survive and be carried
on horses, aoudad sheep, deer, elk and a number of other deer species.
Since October 2008, (the beginning of the 2009 federal fiscal year)
127 fever tick-infested premises in 8 South Texas counties have been
detected and quarantined. Of these, 68 premises are in Zapata County,
51 are in Starr County, and the remainder are scattered among
Maverick, Brooks, Cameron, Kinney, Dimmit and Webb counties. This
year's infested premises tally will eclipse last year's count of 132,
and could meet or beat the record set during the 1973 fever tick
outbreak -- 170 infested premises.
"The Starr-Hidalgo temporary quarantine is the 5th since July 2007 and
was implemented fewer than 70 days after we released nearly 375 000
acres from temporary quarantine in Webb, Dimmit and Maverick
counties," said Dr. Hillman. "We had very good results in Webb, Dimmit
and Maverick Counties, where the tick-infested premises count has
dropped to 5. About 250 000 acres remain under temporary quarantine in
the 3 counties.
"In rural Zapata County, there are no appropriate roads or easily
identified boundaries for establishing a temporary quarantine.
Therefore, to accomplish adequate tick surveillance in Zapata County,
premises within 5 miles of an infested pasture are being temporarily
quarantined." Dr. Hillman explained that ranchers in the temporary
quarantines can move livestock after the animals undergo a clean tick
inspection and treatment by the USDA Tick Force or TAHC.
Dr. Hillman explained that Tick Force and TAHC teams work inward from
the outer edges of the temporarily quarantined area, inspecting
ranches with cattle, horses and wildlife hosts to determine the
outermost spread of the fever tick infestation. Not only do animals
become tick-infested, but so do the pastures, as fever ticks may wait
in the grass for months, before finding a suitable onto a host
animal." said Dr. Hillman.
"When infested premises are detected, the animals and pasture are
quarantined for 9 months or longer, and a variety of tick eradication
measures are taken. Cattle are inspected and run through dipping vats
spray boxes charged with the pesticide CO-RAL. Another treatment being
evaluated in field trials is injectable doramectin. Horses are
sprayed, and wildlife are provided medicated feed or enticed to
treatment stations where their ears and neck rub against
pyrethrin-coated posts while they eat.
Alternatively, once cattle are 'tick-free,' the cattle may be moved to
a new site, allowing the pasture to be 'vacated' for months, causing
the ticks to starve. Greater success is achieved, however, by leaving
cattle in place and continuing to inspect and treat the animals every
14 days with CO-RAL or every 25 to 28 days with doramectin. Ticks
picked up from the grass by the cattle and destroyed by treatment,
eventually leaves the pasture free of the pest. This long and costly
process is a burden to the ranchers who must hire helicopters and
cowboys time after time to round up the cattle from the thick brush,"
said Dr. Hillman.
Add one/Cattle Fever Tick War
-----------------------------
"With each new infested premises, costs rise for the fever tick
program -- more equipment, more personnel, more products and more
time. Sadly, because we have worked so hard to keep this outbreak
contained to South Texas, it is not fully recognized as a national
animal health issue, with potential international consequences," said
Dr. Hillman, Texas' state veterinarian and head of the TAHC, the
state's livestock and poultry health regulatory agency. "The longer it
takes to eradicate this fever tick incursion, the greater are the
chances fever ticks will be spread to other states, which will raise
the costs exponentially. More people, more national resources and new
tick-fighting products are needed now to get this potentially deadly
pest out of the U.S."
Dr. Hillman said the USDA's Natural Resources Conservation Service
(NRCS) is helping ranchers with land management techniques to help
reduce cattle fever ticks, including, but not limited to,
cross-fencing, brush management, prescribed burning and prescribed
grazing to help with livestock handling, to destroy cattle fever tick
habitat, and to help manage wildlife.
For the 2010-2011 biennium, the Texas Legislature appropriated an
additional USD 500 000.00 a year in state funds for the fever tick
program. The TAHC will [use] some of the funds to hire 5 new fever
tick personnel. "The U.S. Department of Agriculture's Tick Force has
received some funding to hire temporary and term workers, but
sustainable, ongoing funding of about USD 15 million per year is
needed to support this program, eradicate the current outbreak and
prevent future problems. I urge industry and lawmakers to support
fever tick eradication while it is still a brush fire confined to
South Texas. The situation with this foreign pest could become a
wildfire, particularly if ticks begin transmitting Babesia, and we
have cattle deaths. We don't need a replay of the 1800s, when
thousands of cattle died from tick fever," he said.
Although the fever tick was declared eradicated from the U.S. in 1943,
it has never been wiped out in Mexico, which serves as a continuous
source for tick reinfestation in Texas. The U.S. Department of
Agriculture's Tick Force has fewer than 60 riders to patrol the 900
miles of the Rio Grande on horseback from Del Rio to Brownsville, and
apprehend 'ticky' Mexican cattle, horses, deer, elk and susceptible
species that cross the river. Detecting ticks in this narrow permanent
fever tick buffer zone is expected, due to the prevalence of the tick
in Mexico, explained Dr. Hillman. "Finding them farther inland
indicates that our defenses are inadequate and that wandering wildlife
or stray or smuggled livestock are spreading the foreign ticks. Today,
60 percent of the fever tick infestations are encroaching deeper into
the 'free' areas of the state," said Dr. Hillman.
The boundary of the new temporary quarantined area in Starr and
Hidalgo counties begins at the intersection of Military and Garza
Roads in La Joya, in Hidalgo County. It follows Garza northward to the
intersection with US Highway 83, where it follows the highway to the
intersection with Jara Chinas Road. The boundary continues north on
Jaras Chinas until it turns northwest on 14 Mile road, then north on
Salazar Road to the intersection with FM 490. The boundary follows FM
490 northwest, crossing the county line into Starr County and
continuing to the intersection with the fence line of El Junco Ranch.
At this point, the boundary turns south, following the ranch fence
line to Las Brisas Road/Pimienta Road, where it continues south to
U.S. Highway 83. The boundary follows Highway 83 southeast, where it
follows Montalvo Road, then Military Road to the intersection with
Garza, the starting point of the zone.
--
Communicated by:
Carla Everett
[As the article explains, it is a very expensive and time consuming
task to eradicate the carrier of this disease. In the 1940's cattle
were dipped in large vats with an arsenic-containing dip. Co-Ral is
not an arsenic dip, but rather an organophosphate, which can inhibit
cholinesterase. This chemical is a restricted use pesticide, meaning
special training and handling is required to use it. - Mod.TG]
[Photo of cattle being run through a dip at
Picture of engorged Texas fever tick _Margaropus annulatus_
Photo of Aoudad (Barbary) sheep at
- Mod.JW]
[A map showing the counties of Texas is available at:
[see also:
2008
----
Texas cattle fever tick - USA (02): (TX) quarantine expanded 20080705.2046
Texas cattle fever tick - USA: (TX), quarantine expanded 20080418.1384
Texas cattle fever tick - USA (TX): quarantine extended 20071005.3292]
....................tg/ejp/jw
*##########################################################*
************************************************************
ProMED-mail makes every effort to verify the reports that
are posted, but the accuracy and completeness of the
information, and of any statements or opinions based
thereon, are not guaranteed. The reader assumes all risks in
using information posted or archived by ProMED-mail. ISID
and its associated service providers shall not be held
responsible for errors or omissions or held liable for any
damages incurred as a result of use or reliance upon posted
or archived material.
************************************************************
Become a ProMED-mail Premium Subscriber at
************************************************************
Visit ProMED-mail's web site at
Send all items for posting to: promed@promedmail.org
(NOT to an individual moderator). If you do not give your
full name and affiliation, it may not be posted. Send
commands to subscribe/unsubscribe, get archives, help,
etc. to: majordomo@promedmail.org. For assistance from a
human being send mail to: owner-promed@promedmail.org.
############################################################
############################################################
Posts
No comments:
Post a Comment