Colleen Schreiberm Livestock Weekly:
The Texas House Committee on Culture, Recreation and Tourism conducted another special hearing to address the chronic wasting disease issue. This one was not held at the Capitol, however, but in Medina County, where four deer in a breeder facility are now known to have tested positive for CWD.
Dr. Dee Ellis, state veterinarian and executive director of the Texas Animal Health Commission, offered an update on the ongoing investigation. TAHC’s goald, he told the committee, is to try to find the source of the disease and prevent its further spread.
As of early September, 49 deer at the index facility had been euthanized and tested for CWD. Of the 49 tested thus far, three were positive for CWD in addition to the originally disclosed positive.
Additionally, there were 30 facilities that transferred deer into the index facility, known for purposes of the investigation as trace-ins, and another 147 facilities that received deer from the index facility, known as trace-outs. To date an additional 205 deer, either trace-ins or trace-outs, have been tested for CWD; all have tested negative.
The trace-in and trace-out herds were issued a hold order, meaning no movement of deer in or out until the animal or animals in question tested negative for CWD or they agreed to adhere to a herd plan developed in conjunction with TAHC. Because the accepted maximum incubation period for CWD is about five years, some of the herd plans will be in effect for five years, but many can be shortened by additional testing this fall or because the potentially exposed deer have been removed from the herd for a period of time.
As of the first week of September, 18 facilities that for various reasons were not able to test out and have the hold order removed, have agreed to a TAHC herd plan. TAHC is still negotiating with 57 others.
“We are committed to options and business continuity and working individually with each herd owner that has a specific problem to try to come up with solutions,” said Ellis.
In particular, TAHC is still negotiating with nine “source” herds, the trace-ins. The issue is that sometimes the animal or animals in question are dead, have been resold, or may already have been liberated.
“When we can’t find the animal we’re looking for, we talk to them about enhanced surveillance,” said Ellis.
That “enhanced” surveillance could be done by testing of other animals, either in the pen or during this upcoming hunting season, in an effort to raise the probability that the herd is not infected.
There are also “trace-out” breeders where the animal or animals in question are already dead or have been liberated and can’t be found. Thus specific surveillance plans are being worked out with those individuals. In one case TPWD granted permission via Antlerless and Spike Deer Control Permits prior to the regular hunting season to harvest from the pasture where these deer were liberated to meet the necessary testing requirements so the hold order on their breeding facility could be removed and liberation and commerce of animals could begin again.
There were also two instances in which the breeder deer were liberated on low-fenced areas. In those particular cases, he said, TPWD will work with the community to establish an enhanced surveillance program in the area.
If a facility has an exposed animal and is unwilling to test that animal, Ellis said, the owner is accepting the fact that he has limited options for movement and liberation, at least for this hunting season.
Ellis also acknowledged that there will be some who simply do not like the herd plan that TAHC has suggested. Those individuals may protest to TAHC. Ellis is the one who actually hears those protests.
“We will listen to them fairly,” Ellis assured the committee. “We always try to work it out.”
The state vet said that at maximum there are still 322 live deer on 41 premises that may be affiliated with the index herd. While there is some federal indemnity money available through USDA, the money has already been depleted for fiscal year 2015. The next fiscal year begins October 1.
“There are at least 79 deer on five premises where the folks are waiting to kill the deer to see if they can get some kind of indemnity,” said Ellis.
He noted, however, that Texas will be competing with other states with CWD for indemnity funds.
“The government is not going to be able to fully subsidize these operations now or in the future,” Ellis warned. “The most they’ll ever pay for an animal is $3000. It doesn’t matter if it’s a cow, horse or deer.”
Ellis reiterated that he is committed to reevaluating the plan in its entirety after further surveillance is conducted this fall.
“I’m committing that we will work with TWPD and go over what we find in the way of surveillance and what does it mean and what can we tweak,” he said.
Ellis also promised that “all options are on the table,” including live animal testing.
“With livestock we always say we don’t want to make the program worse than the disease, and it applies here as well,” he concluded.
In his opening remarks to the committee, Texas Parks and Wildlife executive director Carter Smith reminded members that the interim plan and the testing protocols associated with that plan were designed to address two different things in a disease risk framework — containment to the extent practicable or possible, and disease detection, specifically surveillance of both captive and free-ranging deer herds. As outlined by Ellis, Smith told the committee that the epidemiological investigation is still in the early stages.
“We still have not completed the collection, sampling and testing of all deer from the index facility,” said Smith. “The investigation has not determined the origin or genesis of that disease into that facility, and the investigation has not yet determined the abundance and prevalence and distribution of this disease in other affected breeder facilities, release sites, or free-ranging wild deer herds. In short, there is a lot to do and a lot to learn.”
Smith also noted that TPWD and TAHC are working to manage a disease risk that “cares not one whit about the height of one’s fence or not one whit about the size of one’s ranch.”
The breeder deer movement qualification standards, which were formalized by emergency rule on the 18th of August, Smith told the committee, were ultimately influenced and shaped by the input and feedback from multiple entities from all parts of the deer management continuum. Time, however, was not on their side.
“Is it a perfect plan? Absolutely not. Is it intended to be a permanent one? Let me be real clear on that. No. It is absolutely not,” Smith said.
He reminded the committee that both he and the state veterinarian have pledged publicly that they would revisit the plan at the end of this hunting season.
By law, Smith explained, an emergency rule can be enacted for 120 days. The department then has the ability to extend it for another 60 days. However, because that would still not take them through the end of the 2015-16 hunting season, the plan is for the Texas Parks and Wildlife Commission to adopt the interim rule at their November meeting. He said there would be language included in the interim rule acknowledging that the rule only applies through the current hunting season and as soon thereafter as TPWD and TAHC can evaluate the efficacy of the implementation of the current rules, assess the epidemiological data collected, and promulgate new standards to reflect an appropriate and acceptable risk threshold for the state’s captive and free-ranging herds.
Wrapping up, Smith told the committee that their intent is to collect and evaluate an “artesian well” of data from both captive and wild, free-ranging deer herds across the state. That data will be used to help them make the most informed decisions going forward. Those decisions, he stressed, will be based on sound science. He added that the department fully supports live animal testing in certain herds and within certain risk parameters.
“My commitment to all of you is that we are wide open as to what we will consider.”
TPWD’s wildlife division director Clayton Wolf also addressed the committee. His intent was to share the details of the movement and liberation standards that are being used in the emergency rule. However, he was interrupted repeatedly by committee members with specific questions and never had a chance to present those standards in their entirety.
Wolf noted that the first CWD testing requirements implemented for deer breeders in Texas began in May 2006. Since that time, deer breeders have been required to test at least 20 percent of their eligible mortalities for CWD to be movement-qualified in Texas. Eligible mortalities are those that are 16 months of age and older.
Now that the emergency rule is in place there are three different transfer qualification categories for deer breeding facilities and three different testing requirements for release sites.
The breeder facility classifications are as follows:
— A Tier 1 Facility has either transferred breeder deer to a CWD-positive facility within the previous five years or received deer from a CWD-positive facility in the past five years. If the facility “tests out,” the hold order is lifted and they are no longer classified as Tier 1.
— A Transfer Category 1 (TC1) has a “Fifth Year” or “Certified” status in the TAHC CWD Herd Certification Program.
— A Transfer Category 2 (TC2) has submitted “Not Detected” CWD test results for 4.5 percent of the average adult population in the deer breeding facility for the previous two years or 50 percent of eligible mortalities (minimum of one mortality required) between April 1, 2013 and March 31, 2015, whichever is less. Facilities that do not currently meet these guidelines may undertake additional testing to achieve this status.
— A Transfer Category 3 (TC3) has tested 20 percent of eligible mortalities since May 23, 2006, but has not met the requirements to achieve TC2 status. A facility with TC3 status may achieve TC2 status by submitting a number of “Not Detected” CWD test results equal to or greater than 4.5 percent of the average adult population size in the deer breeding facility for the previous two years.
For purposes of the plan issued under the emergency order, eligible mortalities are those deer that are at least 16 months of age, or at least 12 months of age if the mortality occurred in a facility enrolled in the TAHC Monitored Herd Program.
Then there are release site classifications. Those are as follows:
— A Class I Release Site is one that receives deer only from Transfer Category 1 (TC1) facilities. No testing of hunter-harvested deer is required for Class I release sites.
— A Class II Release Site receives deer only from TC1 and TC2 facilities. Eligibility requires testing 50 percent of the number of breeder deer that are liberated in the 2015-2016 season or 50 percent of hunter-harvested deer, whichever is less.
— A Class III Release Site is one that receives deer from Tier 1 facilities that have tested all exposed deer that are available for testing, or from TC3 facilities. Qualification requires testing 100 percent of hunter-harvested deer, not to be less than the number of breeder deer liberated on that site in that year. All liberated breeder deer that are ultimately harvested on Class III release sites (even if in subsequent years) also must be tested for CWD.
Additionally, all liberated deer must possess an 840 RFID button tag or USDA National Uniform Ear-tagging System tag. All release sites also must be surrounded by a fence that is at least seven feet in height and is capable of retaining white-tailed deer under ordinary circumstances.
Wolf explained to the committee that a TC1 has the highest testing standards. Many of these facilities, he noted, were released ahead of schedule because of the higher testing performance, thus indicating a lower CWD risk potential. Because of their higher testing protocols and lower risk, there are no further testing requirements for deer released on these sites.
On the other end of the spectrum are the TC3 facilities.
“TC3 requirements are essentially the same requirements that we had prior to the adoption of this emergency rule,” said Wolf. “If a facility doesn’t meet the TC3 standards, then basically they remain not qualified to move animals.”
He also explained that a TC1 can release to Class 1, 2, or 3 sites; TC2 can release to 2 or 3, and TC3 can only release to class three sites.
“So if you want to buy deer from a TC2 facility to release on your ranch, our database will generate an e-mail to you that will let you know what the testing requirements are for a Class 2 release site,” explained Wolf. “The receiving party would have to acknowledge whether he accepts those requirements.”
Several committee members questioned how TAHC and TPWD came up with the testing percentages for the various protocols and whether or not they followed what other states are doing in terms of testing for CWD. Ellis affirmed that TAHC’s epidemiologists used statistical analysis, and they deemed the prescribed testing protocols to be reasonable for the short term.
He stated that the emergency rule was not patterned after any other state, primarily because Texas is the only state that allows liberation of captive breeder deer into the wild.
“There is no template to follow; we’re plowing new ground,” Ellis told the committee.
He also pointed again to the time constraint they were under in getting the rules developed so breeder facilities could meet the September 22 liberation release deadline for the upcoming hunting season. And he told the committee that the testing and release protocols were far more liberal than what the commission would ever have considered if a cattle herd was infected with TB or fever ticks.
“When we put statistical values to these animals, some critics would believe they shouldn’t have been released at all,” said Ellis.
“This one deer producer (the index facility) had contact with almost 15 percent of the industry in the last five years,” he reminded. “There are some 1200 permitted deer breeder facilities and 155 or 160 were involved in this one case.
“With the high fence … this was a compromise between complete aversion to risk and putting people out of business,” he told the committee.
There has been much speculation as to where or how the disease came to be in the Medina County deer breeding facility. There is talk about the disease coming from semen straws, but Ellis said science does not support that theory. There is also talk about it coming in on alfalfa hay. Ellis said some research indicates that plants could pick up the prions and be ingested by grazing animals, and there is also the possibility of soil contamination.
That said, the most likely source of the contamination, Ellis told the committee, is that it came from another cervid, as animal to animal via animal secretion is the most common form of transmission. Thus the logic for the assigned protocols was based on this known scientific fact.
There was much discussion about live animal testing. Specifically, one committee member wanted to know if rectal and tonsil samples were being taken in addition to the obex and lymph node samples, which are the gold standard and the only testing procedure currently accepted. Ellis confirmed that for the index herd they are taking samples from the obex and lymph nodes as well as tonsil and rectal biopsy samples. Ellis responded that the lab has not performed rectal or tonsil tests on the trace-out herds or the trace-ins, primarily because of the time constraint and also because the tonsil biopsy, for example, is a “technically challenging” test and few veterinarians in the state are confident and willing to do the test.
Wolf provided specific details on the testing results from the four known CWD positives. The first animal that tested positive was found under normal CWD screening, thus only the obex and lymph node samples were taken. Both the obex and the lymph nodes tested positive.
The second animal had a positive on the obex, lymph nodes, tonsil, and the rectal tests.
On the third animal only the lymph nodes tested positive, and the fourth animal had positive obex and lymph nodes. The private practitioner authorized by TPWD and TAHC to collect the sample did not submit a tonsil biopsy on the fourth animal but did submit a rectal biopsy. That test result is pending.
Ellis reiterated that TAHC is committed to getting the necessary research for live animal testing to be used in the future, “probably by next year.” He noted, however, that because live animal tests can yield false negatives, such protocols will likely call for more multiple tests over some prescribed period of time.
TPWD’s Smith also reiterated his commitment on the record for live animal testing to be used in the future.
“We’re absolutely and unequivocally committed to live animal testing, but a lot of detail has to be worked out,” Smith said.
He also took the opportunity for the record to address comments made by committee member Rep. Lyle Larson. Larson, who has been a proponent of live animal testing since the start of the investigation, said, “I can’t figure out why we’re killing animals that have very little connection to the index herd.”
“Respectfully, I take issue that we are requiring people to sacrifice deer to appease someone,” said Smith. “I honestly don’t understand that statement, and it’s certainly not part of my calculus, so I respectfully disagree for the record.
“I absolutely do not want to discount either the emotion or the economics associated with an individual breeder making a very difficult choice to sacrifice and collect samples on a deer in order to realize a certain movement level qualification,” he added.
Smith also offered more “real” numbers. He pointed out that of the 1318 breeders in the state, 600 required no additional testing to meet the Class 2 release site qualification standards. There were 1000 breeders who either had no further testing or were only required to test one additional animal to qualify as a Class 2 release site.
“That’s about three-quarters of the state’s breeder community,” Smith pointed out.
Furthermore, 1120 breeders, or 85 percent of them, had to test one, two or none at all to qualify for the Class 2 release site.
There were questions posed by the committee about the cost of testing and who pays. Smith explained that TPWD covers the cost of testing of the hunter-harvested samples. Any sample not associated with deer movement but under the department’s permit programs, for example, deer breeder program and the TTT program, the permittee bears the burden of the sampling cost.
Currently, a TTT permittee must test 10 percent of the number of deer permitted to be moved with a minimum of 10 and a maximum of 40.
“It’s actually one of our higher testing thresholds,” said Wolf.
He also pointed out that if they test 60 animals they get a preferred status and their testing requirements go down.
TAHC is covering the cost of any of the required tests associated with the prescribed herd plans that TAHC works out with the respective breeders.
As for the actual cost of the test, because the Texas Veterinary Medical Diagnostic Lab in College Station does the testing, Ellis could only give a ballpark number. He said the testing costs on average about $50-100 depending on whether a vet is doing the sampling and if the whole head is shipped. TPWD gets a slightly better deal of $30 per sample for the hunter-harvested samples submitted from check stations in West Texas, but those samples, Wolf noted, are already fixed in formalin.
Wolf finally addressed the increased hunter harvest surveillance plan they have developed for the 2015-16 season. He first noted that hunter harvest testing will only be required on the areas that are linked to the index facility. Otherwise, Wolf said, hunter harvest sampling is voluntary.
“We will have a lot more folks out there looking, so we’ve budgeted for higher seasonal costs during hunting season and also for the higher testing costs,” he told the committee.
To date, TPWD has collected close to 30,000 CWD samples across the state. The goal has been to get 298 samples per eco-region per year.
“There is a statistical significance to that number,” said Wolf. “If we can sample that many across the population, then we are 95 percent confident that we would detect the prevalence of the disease at one percent.”
Given the latest finding, however, the department has plans to increase the number of samples by looking at resource management units instead of eco-regions. There are 33 resource management units in the state compared to 10 ecoregions, Wolf explained.
He told the committee that the specific plan has not yet been nailed down because the department is in the middle of a risk assessment.
“One of the factors we’re looking at is the deer population estimate for a given area, because the more mouths, the more bodies, the more likely it could be spread,” explained Wolf. “We’re also looking at the number of other CWD-susceptible species in the area.”
The risk assessment is also taking into consideration the proximity to CWD sites, the proximity to exposed herds, as well as the proximity to low-fenced exposed herds and testing history of the area.
“It could be that in our high risk areas we want to go with 99 percent confidence rate that we’re detecting the disease at a one percent prevalence, but maybe in our lower risk areas we stick with a lower confidence level,” Wolf told the committee.
For example, in Medina County they are considering stepped up sampling in a five mile radius of the index facility. The five mile figure was chosen because research has shown that yearling bucks disperse four to five miles, on average, and Wolf noted that yearling bucks roam the most.
“We’re going to have a target of 298 samples in that area,” he told the committee. “That would mean that we are 95 percent confident that we would detect the disease at a one percent prevalence.”
The more samples they can collect, the better the risk assessment will be.
“If we hit 433 samples, that gives us 99 percent confidence that we can detect it at one percent prevalence,” said Wolf.
The plan is to establish two check stations for this area. They intend to add additional personnel on the four busiest weekends of the deer season.
The department also intends to employ a “roving” strategy whereby hunters leave heads behind if the ranch has a cooler in which they can be stored until personnel can pick them up. The department is considering purchasing some transportable refrigerated coolers as well.
Wolf also said the department is planning a public meeting in the area to discuss the strategies, and they intend to personally contact every individual landowner listed on the tax records within a five mile radius of the index facility.
Smith added that the department works with some 10,000 landowners on different harvest programs on more than 24 million acres. He told the committee that increasing surveillance on wild, free-ranging deer is also a priority.
Finally, Wolf noted that the CWD task force recommended that the department consider carcass movement restrictions in the containment zone in West Texas as well as on other sites associated with the index facility.
“We know that the prions are more concentrated in certain body parts,” Wolf told the committee.
The plan, which thus far is in draft form, is to establish restrictions for carcasses moving out of CWD zones and CWD-positive states. Carcasses coming from those zones would have to be quartered and caped so as to have a clean skull cap, leaving the brains and spinal cord behind, where they would be disposed of in the appropriate manner.
The emergency rule as well as the details of the breeder deer movement qualification standards are available on TPWD’s CWD website at http://tpwd.texas.gov/huntwild/wild/diseases/cwd/. TPWD’s next commission hearing is November 5.
UPDATE: CWD Case Confirmed In Lavaca County Deer Breeder Facility
AUSTIN —(TAHC)— The Texas Animal Health Commission and Texas Parks and Wildlife Department have announced that a captive white-tailed deer in a Lavaca County deer breeding facility has been confirmed positive for chronic wasting disease.
The Texas A&M Veterinary Medical Diagnostic Laboratory in College Station detected the presence of CWD in samples submitted, and the National Veterinary Services Laboratories in Ames, Iowa subsequently confirmed the findings.
The discovery at the newly quarantined Lavaca County facility is a result of testing trace-out animals that originated from a Medina County index captive white-tailed deer herd where CWD was first detected on June 30.
CWD was first detected in Texas in 2012 in free-ranging mule deer in far West Texas in the Hueco Mountains. The Lavaca county herd is the second infected breeder herd detected in Texas.
“The investigation of the index facility in Medina County continues,” said Dr. Dee Ellis, TAHC executive director. “The TAHC, TPWD and USDA are diligently working with the breeder deer industry to assess disease transmission risks, and to protect Texas’ free-ranging deer, captive deer, and hunting industries.”
“TPWD will continue to work with TAHC, USDA and stakeholders representing wildlife conservation and deer breeding interests to implement measures appropriate to protect our state’s most popular big game animal, the white-tailed deer,” said Carter Smith, TPWD executive director.
The disease was first recognized in 1967 in captive mule deer in Colorado. CWD has also been documented in captive and/or free-ranging deer in 23 states and two Canadian provinces. CWD among cervids is a progressive, fatal disease that commonly results in altered behavior as a result of microscopic changes made to the brain of affected animals. An animal may carry the disease for years without outward indication, but in the latter stages, signs may include listlessness, lowering of the head, weight loss, repetitive walking in set patterns, and a lack of responsiveness. To date there is no evidence that CWD poses a risk to humans or non-cervids. However, as a precaution, the U.S. Centers for Disease Control and the World Health Organization recommend not to consume meat from infected animals.
More information about the TAHC’s CWD program may be found at http://tahc.state.tx.us/animal_health/cwd/cwd.html