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Anthrax Confirmed in Deer in Uvalde County

White-tailed deer diseases are common. Although most only result in minimal impacts on a local deer population, some deer diseases can can have a severe impact on deer hunting and management activities. Anthrax is one of the diseases that is really good at making deer dead. This bacterial disease not only kills deer, but all other mammals as well. The Texas Animal Health Commission (TAHC) announced in a news release last week that the first confirmed case of anthrax in a Texas animal for 2012 has been detected in a whitetail buck in Uvalde County.

An anthrax outbreak occurred on June 6, 2012, and involved 10 dead white-tailed deer on a newly purchased ranch approximately 20-25 miles north of Uvalde, Texas, on Highway 55 (to Rocksprings). There was one freshly dead deer when the veterinarian visited the ranch, and this was the one he sampled and sent to the Texas Veterinary Medical Diagnostic Laboratory in College Station for confirmation. Information from that sample spurred TAHC’s anthrax news release. The high fenced ranch where the anthrax outbreak occurred has both whitetail and exotics deer species. There are no livestock grazing on the property and the size of the ranch is not available at this time.

Anthrax in Texas - Deer Hunting to be Impacted

The 10 deer are said to have died over a two day interval. This tells me that there are already other prior cases in that general area that either no one is talking about (not unusual), or they have yet to get out and check their stock and watch the vultures. The fact that “ten” deer were affected essentially at once would confirm fly activity, because in dry years, it is usually just single or double deaths and no follow through. The flies feed on an index case, and then with contaminated mouthparts feed on other deer, mammals nearby. From the nature of commercial deer breeding in Texas, the deer density is high, as they are frequently fed with protein pellets or cracked corn at multiple feeding stations, so the female flies do not have trouble finding another deer to feed upon, infect and kill.

The new ranch owner had been moving dirt, as new owners often do, and it is theoretically possible he had disturbed an old anthrax grave site, which, with the recent four to six inches of rain, the turned soil could have sprouted some tasty deer foods. Though normally browsers, whitetail deer will graze on fresh, succulent grasses. Anthrax outbreaks based on grazing usually start with a single affected animal from which the infection spreads. Ten “at once” is not likely to be from grazing, but the full story has yet to unfold.

Because of the increase in rainfall in early May 2012 in the area bounded by Interstate 10 and Interstate 90, essentially between Uvalde and Sonora, Texas state veterinarians had been warning the local deer ranchers of the risk from a sudden tabanid hatch and resulting anthrax outbreaks involving numbers of animals. Additionally, they have been reporting a lot of flies in the area. Unfortunately, it looks like they have been correct their prediction about this deadly deer disease. Expect an active summer in this part of Texas, where wildlife anthrax is endemic.

Whitetail Deer Diseases - Anthrax in Deer in Texas

TAHC News Release:

“Anthrax Case Confirmed in White-tailed Deer near Uvalde

The first confirmed case of anthrax in a Texas animal for 2012 has been detected in an adult white-tailed male deer near Uvalde (Uvalde County). At this time no domestic livestock are involved.

Anthrax is a bacterial disease caused by Bacillus anthracis, which is a naturally occurring organism with worldwide distribution, including Texas. It is not uncommon for anthrax to be diagnosed in livestock, whitetail deer or other wildlife in the Southwest part of the state. In recent years, cases have been primarily confined to a triangular area bounded by the towns of Uvalde, Ozona and Eagle Pass.

“The TAHC will continue to closely monitor the situation for possible new cases across the state. Producers are encouraged to consult with their veterinary practitioner or local TAHC office about the disease,” Dr. Dee Ellis, State Veterinarian, said. For more information regarding anthrax, visit the Texas Animal Health Commission website or call 1-800-550-8242.”

CWD Regulations on Red Deer, Sika Deer

Texas has been keeping an eye on Chronic Wasting Disease (CWD) for a number of years now. Whitetail, mule deer and elk are known to be highly susceptible to the disease. CWD poses a significant threat to the social and economic importance of both mule deer and whitetail deer hunting in the state. State agencies have done as much as possible to safeguard CWD from entering into Texas by regulating the movement of deer through the commercial deer breeding industry, but CWD is currently knocking on Texas’s door, found just north of the Texas-New Mexico border in the Trans-Pecos region.

To complicate matters, recent findings have discovered that other ungulates can carry the disease. This has resulted in two more deer species being added to the list of “CWD susceptible” species, the Red deer and the Sika deer, both exotic species commonly found with whitetail deer on hunting ranches across Texas. The Texas Animal Health Commission (TAHC) announced that effective immediately it is has determined that Red deer (Cervus elaphus), and Sika deer (Cervus nippon) are “susceptible species” for Chronic Wasting Disease (CWD) and thereforemust meet the same entry requirements as other cervid species regulated by the agency such as moose and elk.

Deer Hunting in Texas - Red Deer and Sika Deer CWD Regulated Now

The new entry rules for Red deer and Sika deer will require they originate from herds with at least five years of participation in a herd certification program from states where CWD has been detected, and at least three years participation in programs from states that have not found CWD thus far. The TAHC decision was based in part on the disclosure that a farmed Red deer herd in Minnesota was confirmed positive for CWD in May of this year.

Additionally, the United States Department of Agriculture (USDA) released an interim final CWD rule on June 8, which designates Sika deer and Red deer as susceptible CWD disease species. The USDA rule is intended to establish minimum requirements for interstate movement of all deer, elk, moose, and other susceptible cervids, and to also establish a national CWD certification program.

Under the new deer entry requirements, besides originating from a herd with three or five year status as described above, Red deer and Sika deer shippers must also obtain an entry permit and request entry in writing. Proper supporting documentation must also accompany the request for entry at least 10 days prior to the proposed entry date. More information on TAHC entry requirements related to cervids can be found in Texas Administrative Code.

Sika Buck - Deer Hunting in Texas

Native cervid species such as white-tailed deer and mule deer are regulated by the Texas Parks and Wildlife Department (TPWD), not the TAHC. Currently those species are entirely prohibited from entering Texas based on TPWD rules. Will all of these agency regulations prevent CWD from enter Texas? The answer is definitely no, especially since a deer (probably a mule deer) carrying CWD can walk right into West Texas. The bigger question is, “Will CWD ever severely impact deer hunting in Texas?” That I do not know, but I’m definitely in favor of slowing the spread of CWD and waiting as long as possible to find out.

Deer Nutrition Key for Better Hunting & Fawn Survival

A Look at Deer Nutrition

Rainfall (received or not received) during the first half of the year dictates deer hunting season. Although the rains dried up recently, many areas received good amounts of rain throughout the late-winter and early-spring. This will generally improve deer nutrition. However, it’s almost summer and more often than not it’s dry. Strong spring rains equate to better than average body condition in all deer and enhanced antler growth in bucks.

Summer rains are an appreciated bonus and can provide stable nutrition for whitetail deer herds during what is often a hot and dry stress period. The best way to manage for disappearing forage is through supplemental feeding. Thanks in a large part to the rain received this spring, in addition to the abundance of high protein forbs it produced, many deer managers reported sharp declines in protein consumption by deer. This is good for the pocket books and good for the deer, too.

“Supplement” to Improve Deer Nutrition

When it comes to quality, nothing competes with the nutrition offered by high quality forbs and new-growth browse. Forbs are weeds and wildflowers. Browse is the leaves, stems and twigs of woody plants. These foods are the best of the best, often packing high protein levels that make pelleted feeds look weak in comparison. Currently, good habitat conditions exists around the state. However, I have a feeling that things get really dry all over again. Now is the time when the “supplemental” part of supplemental feeding comes into play.

Dietary supplements for deer compliment foods naturally available. This helps improve deer nutrition during stress periods. Do not use supplements to provide everything a whitetail needs. Otherwise, that’s called complete feeding. If this is the case, it’s time to reduce the deer population.

Looking at Nutritional Stress

Does start dropping fawns in late-May over much of the whitetail’s range. However, most of the fawns drop during the month of June in Texas. Supplemental forage, which includes pelleted protein, whole cottonseed, roasted soybeans and food plots (irrigated or otherwise), help compliment deer nutritional requirements during the summer. Many provide supplements to deer to increase antler growth. Hunters like big bucks. More importantly, scientific data says supplemental feeding elevates deer productivity and survival, which increases the density of the deer population.

Healthy deer results in an increase in deer density (after fawns are born). This can be correctly diagnosed through deer surveys performed during the late- summer, then properly treated through harvest during the deer hunting season. However, from a nutritional standpoint, early-May is a long way from the fall. Fall is the next boom of natural foods, but deer nutrition can wane during the summer, especially in Texas.

Summer, like winter, is a tough time of the year for deer. It’s important to keep in mind because the the most expensive nutritional part of a doe’s annual cycle is in raising fawns. Mother Nature has already provided for all of her needs to date, but it’s going to get worse before it gets better. A lactating doe that is on a high plane of nutrition can be expected to raise more or at least more healthy fawns. With temperatures heating up and fawns about to drop, this is also the time of year when doe greatly benefit from supplementation.

Rainfall Provides Nutrition

A wet spring season means a strong start to the year for deer. Good spring rains provided a bounty of foods for native wildlife and domestic livestock. Even without another drop of rain (hope not) until the fall, habitat looks better for deer than they did in 2011. Deer in many areas improved in body condition through the fall and winter thanks to heavy acorn crops, mild temperatures and good rains. However, it did make for tough hunting.

READ: Management to Improve Deer Nutrition

If the trend of favorable environmental conditions continues through the spring, then I suspect hunters experience a really good deer hunting season. Let’s hope we catch a few rains throughout the summer to help get these deer through to the other side. Manage livestock grazing to preserve fawning habitat and to bank valuable deer browse into the summer. Again, it’s been a good year to date, which is good for antler growth and fawn production. That’s all good for hunters!

CWD in Texas?

Chronic wasting disease (CWD) is basically the “mad cow disease” of elk, mule deer and white-tailed deer. CWD is not new; the deer disease has been on the radar of state wildlife departments for decades. CWD was first diagnosed in 1967 in a captive herd of mule deer in Colorado and not long after was found naturally occurring in that state as well as Wyoming. It was not until 1996 that the deer disease was found outside of that area. It was at that time when many states started monitoring for the highly contagious CWD.

Hunters are always concerned about wildlife diseases, especially the highly infectious ones such as CWD, that impact game animals. It is also the responsibility of state and federal wildlife agencies to reduce the transmission of all wildlife diseases while attempting to learn more about the problem. Wildlife management – deer management specifically – is about taking the steps necessary to react to an ever-changing environment to reach certain objectives. One of the biggest variables for whitetail deer is food availability, but most hunters control for this factor through deer harvest, food plots and supplemental feeding.

CWD in Whitetail Deer: The Disease May be Found in Texas Soon

More variables = more unknowns. A higher number of variables makes it increasingly difficult to manage for a desired result. CWD has not shown to be the end all of whitetail populations in any area, but it is another variable that does negatively impact deer populations in areas where the disease is found. CWD can drastically reduce a local deer population, but not all animals necessarily die from the disease. In Texas, CWD monitoring has taken place for over a decade, but no positive samples have ever been found. That may be about to change.

Source: “The New Mexico Department of Game and Fish (NMDGF) has informed Texas officials that three mule deer harvested a few miles from the Texas border last hunting season have tested positive for Chronic Wasting Disease (CWD).

The deer were harvested in the Hueco Mountains, which extend into Texas northeast of El Paso in Hudspeth County. New Mexico has been monitoring annually for CWD since it was first discovered 10 years ago and this event is the closest to Texas that the disease has been detected. Texas also has had an active CWD surveillance program for the past decade, and CWD has not yet been detected in the state. However, state wildlife officials have been preparing for the possibility since 2002.

“While this finding is not a big surprise, we’re not going to ignore it,” said Mitch Lockwood, Big Game Program Director for the Texas Parks and Wildlife Department. “We are working with TPWD’s Wildlife Health Working Group to develop a more intensive strategy for sampling, and to determine the geographical extent of the disease if it is detected in Texas.”

The Wildlife Health Working Group is comprised of wildlife biologists, veterinarians and other animal-health experts from TPWD, Texas Animal Health Commission, Department of State Health Services, Texas A&M College of Veterinary Medicine, and USDA. The New Mexico Department of Game and Fish is also involved in the discussion.

While several thousand deer have been tested for CWD in Texas, wildlife officials express concern that the Trans Pecos region is underrepresented because of the very low number of deer and the relatively low deer harvest in that region. Samples are obtained from hunter-harvested deer, deer found dead on public roadways, and deer showing clinical symptoms. TPWD is determining how many more deer need to be sampled and deer hunters in the region could be asked for their assistance during the next hunting season.

“We are using disease models to determine the intensity of sampling that would be required to detect CWD in that deer population if it is present with a prevalence of at least two percent,” said Ryan Schoeneberg, Big Game Program Specialist with TPWD.

CWD was first recognized in 1967 in captive mule deer in Colorado and has also been documented in captive and/or free-ranging deer in nearly two dozen states and Canadian provinces, including New Mexico. Although fatal in deer, there is no evidence that CWD poses a risk to humans or livestock in the natural environment.

“It would be almost impossible to eradicate the disease once it becomes established in a population,” said Lockwood. “But, what we can do is manage the disease and minimize the risk of it spreading.”

CWD is a member of the group of diseases called transmissible spongiform encephalopathies (TSEs). Other diseases in this group include scrapie in sheep and goats, bovine spongiform encephalopathy (BSE or mad cow disease) in cattle, and Cruetzfeldt-Jakob disease in people. CWD is a progressive, fatal disease that affects deer, elk, moose, and other cervid species and there is no vaccine or other biological method that prevents it.”

Deer Aging: Whitetail Aging Chart Uses Tooth Measurement

Hunters interested in producing and growing bigger, more healthy whitetail understand that active deer management is the key to long term success. An important component of a successful deer hunting and management program is being able to accurately age white-tailed deer, specifically bucks.

The selection of bucks suitable for harvest is most often performed by aging deer on the hoof in the field, but that determination is often evaluated by aging harvested deer using the tooth wear and replacement method. Neither of these methods are foolproof.

Determining Age of Live Deer

Aging deer on the hoof relies on the observer being able to objectively judge an animal based on physical characteristics. It’s an acquired skill that hunters can get better with over time, but its’ not perfect. This technique can be enhanced by allowing observers more time to look at individual animals, which is often accomplished using game camera photos placed in feeding areas.

Numerous photos from various angles usually allow a hunter to get a good idea of deer’s age before even heading to the field. Observation of the animal before or during the deer hunting season can then be used to confirm or reject the armchair evaluation of the deer’s age.

Deer Hunting - Deer Aging for Whitetail Deer Management

The tooth wear and replacement technique is most commonly used on dead deer, although persons involved in the legal trapping and transporting of wild deer as well as commercial deer breeders may use the method on live deer. There are, however, a number of variables that can impact tooth wear in deer.

The teeth of whitetail found living over sandy soils will wear quicker than those found living over clay soils. Deer that eat a lot of protein feed will wear down slower too. But like most things that require skill to get better, confidence and consistency with the deer aging technique takes time. So is there a better way?

Tooth Aging Chart for South Texas Deer

Source: Researchers at the Texas AgriLife Research and Extension Center in Uvalde have developed a more accurate technique than traditional methods for estimating the age of white-tailed bucks. When owners or managers know the true age of harvested deer on their ranch, it improves their ability to predict the age of live deer on that property.

“South Texas is famous for producing trophy white-tailed deer,” said Dr. Susan Cooper, AgriLife Research associate professor and lead investigator for the new age-estimation research. “Large-antlered deer sell for very high prices, so harvesting a good buck before it reaches its prime or after it begins to decline can represent a significant loss of income to the producer.”

“The traditional method for estimating the age of white-tailed deer has been by visual, tooth-wear patterns,” Cooper said. “This method – known as the Severinghaus technique – was developed using northern deer and is inaccurate for estimating the age of wild deer in Texas beyond the rough categorizations of young, mature or old.”

The new technique also relies on using the animal’s teeth, but involves measuring the width of the dentine — the hard tissue located under the enamel of a tooth — on a specific tooth.

Cooper said over the past 10 years the wildlife team at the Uvalde center has ear-tagged more than 2,000 wild buck fawns on South Texas ranches. During the past decade, ranch owners and operators have kept tabs on ear-tagged deer, collaborating with the center on deer-related research. “When these bucks are harvested, the partner ranch returns any known-age jawbones from tagged deer to us for evaluation and assessment,” she said.

Cooper said research assistant Shane Sieckenius had noted that an actual measurement of tooth wear would be superior and more accurate than a basic visual scoring system would be in aging white-tailed deer.

After discussion and evaluation, the team determined the first permanent molar would be the tooth which was most likely to show age-related wear patterns. Using digital calipers, they took accurate measurements in millimeters of tooth height, as well as all ridges of white enamel and brown dentine on the tooth from jaw samples of harvested known-age bucks 2.5 to 7.5 years old.

“We wanted to see if we could go to just one location in the jaw to reduce the amount of variability of age-related wear within the jaw,” Sieckenius said. “This particular tooth was consistent in showing the true indication of wear.” Cooper said evaluation of measurement data revealed that only the width of the dentine in the tooth’s cusps, pointed ends of the chewing surface, was related to the age of the deer.

“The best measurement fit for aging was the width of the dentine, which we gave the value D, in the front cheek-side cusp of the first molar on the right side of the jawbone,” she said. “This provided us with the relatively simple formula for estimating age: 1.8 times D, plus 1.8.”

She said the only equipment needed for the study was the digital calipers, which can be purchased from major online retailers for as little as $20 each. “To save doing the math, measurements can be compared to a simple chart that we have developed and will make available to landowners,” she said.

“You have to get the jaws good and clean before measuring, so in our case we boiled the jaws thoroughly to ensure they were free from any tissue, decay or foreign objects that might hinder obtaining an accurate measurement,” Sieckenius said.

Cooper said when tested on a sample jaws of 141 bucks, the formula predicted the correct age for 61 percent of young bucks aged 2.5 to 3.5 years; 53 percent of mature bucks aged 4.5 to 6.5 years, and 25 percent of old bucks aged 7.5 to 8.5 years. She added that all animals were correctly aged within one year of their actual known age.

For comparison, Cooper said, 27 wildlife professionals and students were asked to age samples of the same jaws using traditional visual tooth-wear measurements.

“They estimated the correct age for 40 percent of young bucks, but only 18 percent of mature bucks and none of the old bucks,” she said. “This means the new technique – which we have named the AgriLife Dentine Method – of aging deer provides much greater precision in aging harvested deer.”

Sieckenius said the new aging technique will be of particular interest to ranchers and hunting lease owners who wish to harvest deer at a specific age.

“This new measurement process is very interesting,” said Jim Hillje, a wildlife consultant for many South Texas ranches and a former Texas Parks and Wildlife biologist. Recently, Sieckenius traveled to Encinal to demonstrate the new technique to Hillje and Jeff Pierce, manager of the 7-1 Ranch in Webb County.

“It’s good to have a more precise way of aging a particular deer, and this new method works well in conjunction with the buck ear-tagging we’ve been doing for several years to confirm the deers’ age.”

Hillje said while he is satisfied that the new technique is an improvement in age-estimating methodology, the down side of current age-measurement techniques is the difficulty in applying them to live deer specimens.

“Landowners want to harvest deer at their maximum antler potential,” Sieckenius said. “Some want to harvest them at five years old and some farther south may prefer to harvest when they’re closer to six years old. We’re giving them a means by which to maximize that potential so they can get the most for their hunt.”

The AgriLife Dentine Method of aging deer does provide measurable physical factors for the aging of harvested deer, but the fact remains that the deer must be in someone’s hands, and dead. The method will accurately determine the age of an animal 60 percent of the time or get within one year of age. With this stated, I’m not convinced that this way is really any better than the old-standby Severinghaus tooth wear technique.

Review of the Deer Aging Chart

The technique uses measurable tooth wear, kind of a modified Severinghaus method, so the new deer aging technique will only be applicable to those deer hunting in South Texas or in areas that have very similar soil and habitat conditions to South Texas.

As mentioned earlier, there are many factors that can impact tooth wear in deer. Soil type, plant communities, supplemental foods and even genetics can affect tooth wear in individual animals. This techniques is still far from perfect, but could offer value to those with little experience aging dead deer.