Category: Disease, Parasites & Virus

CWD Discovered in Texas

Chronic Wasting Disease (CWD) has been confirmed in free-ranging white-tailed deer in Texas. Yesterday, Texas Parks and Wildlife Department (TPWD) announced that a free-ranging white-tailed deer in Medina County tested positive for CWD. The disease had been previously documented in mule deer and elk (in the Texas Trans-Pecos and Panhandle) and in whitetail associated with two deer breeding facilities, but this is the first time CWD has been found in a wild white-tailed deer in Texas.

The deer was harvested during the deer hunting season for Medina County. The hunter brought the 1 1/2 year old buck deer to a voluntary CWD check station located within the surveillance zone that extends across portions of Bandera, Medina and Uvalde counties.

TPWD and Texas Animal Health Commission (TAHC) are taking steps to deploy an early detection and containment strategy designed to limit the spread of CWD from the affected area and better understand the distribution and prevalence of the disease.

“Although the disease has been discovered in a free ranging whitetail in this area, we cannot draw any conclusions at this time based on one detection,” said Dr. Bob Dittmar, TPWD’s Wildlife Veterinarian. “The proactive measures we are taking as part of our epidemiological investigation into this case are in line with the state’s strategies to prevent this disease from spreading any further. The more effective we are at containing this disease within a limited geographic area, the better it will be for our wildlife resources and all those who enjoy them.”

CWD Containment Zone Formed

Effective immediately under an executive order issued by TPWD Executive Director Carter Smith, Surveillance Zone 3 (SZ3), which extends across portions of Bandera, Medina and Uvalde counties, is now a CWD Containment Zone and all associated rules for that designation are in effect. Those rules include restrictions on the movements of carcass parts as well as live deer possessed under the authority of a permit. The department is also implementing mandatory CWD testing of hunter harvested deer within this containment zone.

“This emergency action allows us to contain the threat of this disease spreading any further while we collect more information and gather more data,” said T. Dan Friedkin, Texas Parks and Wildlife Commission Chairman. “Not only are these temporary emergency measures necessary and consistent with the state’s planned strategies for CWD management, they are essential for ensuring the protection of the state’s whitetail deer herd and the integrity of our hunting heritage.

“It is my intent for the Commission to address this issue through our regular rulemaking process, which provides opportunities for public comment and input from stakeholders, and that process will begin soon,” Friedkin added.

“With the confirmation of CWD in a free-ranging buck in Medina County, the TAHC is working with TPWD to determine the disease risk in the area,” said Dr. Susan Rollo, TAHC State Epidemiologist. “TAHC understands and appreciates TPWD’s immediate response and temporary measures to prevent the inadvertent spread of CWD to other parts of Texas.”

CWD Sampling

This most recent detection of CWD resulted from enhanced voluntary testing of hunter harvested deer in SZ3. The TPWD sampling goal for SZ3 for the 2016-17 hunting season is 1,749 samples. As of today, the department has received about 720 samples from hunter harvests and roadkills within the zone and anticipates receiving about 200 additional samples from deer breeding facilities and associated release sites in SZ3.

“TPWD is very appreciative of the effort and cooperation that has been put forth by landowners, hunters and local officials in the area,” said Carter Smith, TPWD Executive Director. “Our ability to control this disease is directly related to the cooperation offered by the citizens of Medina, Bandera and Uvalde counties, and we pledge to continue to work with everyone to minimize the impacts of this disease as well as these challenging but necessary measures designed to control the spread of CWD.”

While the general deer hunting season is over, TPWD will continue to collect samples from MLDP (Managed Lands Deer Program) properties in the new Containment Zone as well as roadkills. The agency is seeking as many additional samples for testing as it can obtain in order to get a better handle on the geographic extent and prevalence of the disease in this area.

CWD in Medina County

CWD was first discovered in Medina County in a dead buck in a white-tailed deer breeding facility in June 2015, with additional deer from that facility subsequently testing positive. The surveillance zone that includes portions of Bandera, Medina and Uvalde Counties was established in response to those positive samples.

CWD started in Texas with positives in mule deer in the far west and then the panhandle. The distance between the always-fatal deer disease and the stronghold of Texas’ whitetail herd offered some degree of comfort for the majority of deer hunters. Then CWD popped up in breeder facilities found in Medina and Lavaca Counties. Now the epicenter of CWD in Texas’ free-ranging whitetail herd is Medina County, which is much closer to home for many Texas hunters. The saga continues, but how does it play out?

CWD & Moving Harvested Deer

Question: “How do we prepare harvested deer in Texas to be transported to other states which have regulations related to CWD? The regulations for transporting harvested deer from other states to Mississippi are contrary to Texas requirements for transporting deer. Mississippi requires all meat to be deboned with no skin or heads to be brought into state unless mounted by a taxidermist or a boiled down head plate with antlers.

This is contrary to Texas requirements which says that the head with hunting license tag must accompany 2 front quarters, 2 hind quarters and 2 back straps. This prevents me from taking deer from Texas to my home in Mississippi. Do I have to stop hunting in Texas? What can I do to remedy this problem and adhere to both state’s requirements? Please let me know as my hunting trip to Texas in coming up in November.”

Transporting from CWD-Positive States

Mississippi and other states where Chronic Wasting Disease (CWD) has not been documented have passed regulations that prohibit the importation of cervid carcasses and deer parts from states where CWD has been found. A cervid is a member of the deer family and includes white-tailed deer, mule deer, elk, moose, caribou, red deer, sika deer, and fallow deer. Many states have carcass import bans, even those that have already found CWD within the state.

The goal of these importation rules is to prevent hunters from inadvertently fast-tracking the spread of the neurological disease that is fatal to deer. As of October 1 2016, CWD has been found in 24 states within the continental US and the Canadian provinces of Alberta and Saskatchewan, as well as the countries of Norway and South Korea.

CWD has been confirmed in the following states: Arkansas, Colorado, Illinois, Iowa, Kansas, Maryland, Michigan, Minnesota, Missouri, Montana, Nebraska, New Mexico, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming.

Texas Deer Hunting Regulations

In Texas, a hunter may skin and quarter a deer into 2 forequarters, 2 hindquarters and 2 backstraps and possess them for transport, provided the quartered deer is tagged and proof of sex accompanies the deer.

Texas hunting regulations also require the head as proof of sex for harvested deer. The regulations state that it is unlawful to possess a deer with proof of sex removed unless the deer is at a final destination and has been quartered. The regulations go on to say that proof of sex for a deer is:

• the head (skinned or unskinned) of a buck deer with antlers attached
• the head (skinned or unskinned) of an antlerless deer
• a completed Managed Lands Deer Permit (MLD), Landowner Assisted Management Permits (LAMPS), or TPWD Drawn Hunt Legal Deer Tag

There are, however, three exceptions to the proof of sex requirement covered in Texas’ hunting regulations. Texas Parks and Wildlife Department (TPWD) regulations read, “Instead of proof of sex, the hunter may obtain a (1) receipt from a taxidermist or a (2) signed statement from the landowner or the landowner’s agent,” and it was recently published that a (3) CWD receipt from a CWD check station also serves as proof of sex.

Basically, there are a number of ways to meet the proof of sex requirement without having to maintain possession of the head. This allows complete disposal of antlerless/doe heads. For bucks, it also allows hunters to transport antlers with cleaned skull plates in compliance with CWD import rules for their home state.

Preparing Harvested Deer

But what about bone-in fore and hindquarters? At the time of writing, Texas hunting regulations only allow hunters to legally process harvested deer down to 4 quarters and 2 backstraps until the animal reaches its final destination. Period. End of story.

Even in Texas’ 2 CWD zones, where mandatory testing is required on all hunter-harvested deer, hunters are still allowed to transport quarters out to other parts of the state. The problem is that what is legally required in Texas all of a sudden becomes a game violation when those fore and hindquarters are brought into a state that has banned bone-in meat from CWD states.

Transporting Harvested Deer: Process ‘Em

For hunters living in states with cervid carcass import bans, there appears to be only one way to lawfully take boneless venison out of Texas, have your deer processed before bringing it home. There are two options, however, when it comes to processing harvested game. Deer and other cervids must be brought to either (1) a commercial deer processing facility or (2) a “private processing facility.”

A private processing facility is a processing facility that is not available for use by the public. The processing facility must be stationary facility that is on-site and is designed and constructed to process game animals. There does not appear to be any registration process involved in setting up such a facility, but any place operating as such must meet the requirements previously mentioned and maintain a “Cold Storage or Processing Facility Record Book.”

It would take some resources to put together such a place, even if the site was simply a small building with water, table, grinder and a freezer of some type, but it could be well worth it depending on the number of animals harvested by the hunter or hunters off a property annually.

In closing, to follow the rules of the state you are hunting in as well as that of your home state, you will need to have all deer processed, either by a commercial or private processing facility, before crossing a state line. It appears to be the only legal way.

CWD is Moving

Chronic wasting disease (CWD) is a big deal for deer populations, deer management, and deer hunting — and for many reasons. First, it’s a threat to white-tailed populations throughout the deer’s range. Secondly, it is a huge point of contention between hunters and deer breeding operations as well as hunters and state natural resource agencies. The fact is that nobody really knows how CWD will impact free-ranging deer herds over the long term.

It’s a little disturbing for those of us that enjoying hunting white-tailed deer in the fall and consuming venison throughout the year with our families. At a time when the importance of recruiting new hunters is much of what we hear and read about, CWD itself, or the resulting management of the disease, may potentially push current and additional, potential hunters away. Who knows?

Fast-Tracking CWD Transmission

What is known: CWD is fatal to any deer that gets it. It’s a naturally occurring disease. Infected animals can infect other animals. Healthy animals can become infected while living in an infected environment. The rate of spread from one area to another can be increased by people moving deer infected with CWD. CWD has been found in 23 states, to date.

It’s generally thought that older bucks are the CWD-prone animals, but new research suggests that does are more likely than bucks to spread CWD within their range. According to reports of the study:

Fewer female white-tailed deer disperse than males, but when they do, they typically travel more than twice as far, taking much more convoluted paths and covering larger areas, according to researchers in Penn State’s College of Agricultural Sciences.

These findings, from a study in which 277 juvenile female deer were fitted with radio collars, has important deer-management implications in states where chronic wasting disease is known to be infecting wild, free-ranging deer, noted researcher Duane Diefenbach, adjunct professor of wildlife ecology.

“Dispersal of female deer is density dependent, meaning that higher deer densities lead to greater dispersal rates.” He explained. “Therefore, reducing deer density will reduce female dispersal rates—and likely will reduce disease spread.

CWD More Likely in Bucks

Past studies have shown that older bucks are more likely to have CWD, to test positive for it. This makes sense to me because even though the new research out of Pennsylvania suggest that does are more likely to spread the disease through dispersal, bucks likely encounter more does during the breeding season, which increases their chances of contracting the fatal disease.

It’s been suggested that bucks be targeted by hunters to slow the spread, but no one can say for sure whether or not this strategy has worked or will work for sure. In Wisconsin, yearling bucks and does were found to have CWD at a similar rate, about 3.5 percent, in areas where the CWD disease was “most prevalent.” Those are only year-and-a-half old deer, which means both sexes are going to test out at significantly higher rates as they age.

The Penn State research gives some merit to herd reduction plans commonly implemented by state natural resource departments throughout the US; a decrease in deer density and shorter dispersal distances will reduce the rate of spread of CWD within deer populations. It’s paramount that it be pointed out that the end result is still fewer deer. CWD itself, or the control strategies implemented to reduce the spread of the disease, both lead us to the same end-point, reduced deer numbers, reduced hunter opportunity and a continued decline in hunter recruitment.

Scientists believe that the prions that cause CWD in white-tailed deer can persists for years, maybe even decades, in the soils in areas that have become infected — even after all of the deer are gone. If we remove all of the deer to prevent the spread of the disease, then what will we be left with?

Fortunately, CWD kills deer slowly. In fact, it’s been reported that a deer must have CWD for almost a year before it will even test positive for the disease. CWD is always fatal to a deer, but since it works slowly the biggest initial threat to most management programs will be reduced age structure in bucks. Even fewer bucks will reach old age as the disease becomes more prevalent, assuming hunting pressure remains constant. That’s a big assumption. Only time will tell.

Corn and Deer

The disease termed acidosis can occur anywhere when wild or domestic white-tailed deer, cervids or ruminants ingest large quantities of readily digestible carbohydrates. Often times, these food are grains such corn but acidosis in deer can also be caused by beets, apples and any other high carb, highly fermentable food. Acidosis is whitetail is characterized by indigestion, a static rumen, dehydration, diarrhea, toxins in the blood, a lack of coordination and death.

Acidosis can occur relatively quickly in whitetail whenever there is a SUDDEN and SUBSTANTIAL increase in carbohyrates in the animal’s diet. Within 24 hours of grain ingestion deer may be recumbent (down), staggering or standing quietly. Death from corn toxicity can occur within 24 to 72 hours. The rumen is usually static accompanied by diarrhea. The deer is essentially “poisoned” and dehydrated.

Corn and Acidosis

Corn is readily available and commonly fed to deer by hunters and non-hunters alike. Where legal, corn is the most widespread bait during the hunting season and there is no doubt that deer will eat it readily. Corn is high in carbohydrates and this is attractive to deer, especially during very cold periods when the seek out high energy foods. Corn consumption by deer is not necessary a bad thing. They can handle it. It’s only when they eat too much of it, when it suddenly becomes a major component of their diet.

Source: Corn causes problems in the deer’s digestive system because of characteristics of both corn and the deer. Corn is composed primarily of starch, which is meant to serve as an energy source for the corn seedling after germination. The starch intended for use by the growing corn plant is also readily available to the deer, which is why deer crave corn. Although starch is an important source of energy, it may be a problem for deer because deer are ruminants.

The Pathology of Acidosis

So how do corn or other high carb/starch foods cause problems for deer? Well, a shift from a natural diet of high fiber woody browse to low fiber, high carb foods is what starts the illness known as acidosis. The severity of the disease in deer depends on the type of grain, previous exposure of the animal to the grain, the amount consumed, the animal’s nutritional state and physical condition, and the microflora present in the animal’s digestive system.

The rapid intake of  high carb foods can cause problems in deer almost immediately. Ingestion of toxic amounts of corn and other starches are followed within 2 to 6 hours by a change in the microbial population in the rumen of the deer. The number of Streptococcus sp. bacteria increase dramatically and replace the normally abundant, “good” bacteria.

This sudden increase in Streptococcus sp. bacteria produces large quantities of lactic acid. This results in the rumen pH falling to or below 5, destroying protozoa, cellulolytic organisms, and lactate utilizing organisms, and reduces rumen mobility. Suddenly, the digestion and movement of food within the deer stops. Chemical rumenitis and absorption result in lactic acidosis.

The lactic acid and lactate build-up cause excessive quantities of fluid to move into the deer’s rumen, causing dehydration.

How to Identify Corn Toxicity in Deer

Acidosis is diagnosed when deer in otherwise good physical condition are found to have died quickly and there are large quantities of corn in the stomachs. A common way to diagnose acidosis is by checking for dark colored lesions (eroded areas) on the lining of the stomach. These lesions are typically located on the folds but can be observed anywhere in the stomach.

There is no treatment for rumen acidosis in white-tailed deer and other wild ruminants because they usually found dead. A deer can survive if the high carb food is no longer available (removed, completely consumed). However, the animal will likely have a permanently damaged rumen lining.

Deer Management: Preventing Acidosis

Many people feed deer, although most of the time it is hunters that feed deer regularly and in volume through supplemental feeding programs. Some suburban homeowners feed deer with regularity too. Corn is commonly consumed by deer without issue. It’s also commonly used by hunters as bait prior and during the hunting seasons.

Corn and other high carb foods are not a problem for deer as long as they are introduced gradually into the diet and as long as they do not comprise the MAJORITY of the animal’s food intake. As such, acidosis can occur during the summer, but is more likely to occur during the winter when leafy forage is lacking. This is because without other available foods and a high need for energy, deer will readily consume any food available to them during this period.

The supplemental feeding of whitetail deer and other wild ruminants (mule deer, elk) is often the cause of corn toxcity/acidosis. The free-choice feeding of high carb foods is not recommended. Most hunters that feed corn by hand or use spin feeders to attract deer to an area for hunting do not distribute enough for it to comprise a substantial part of a single deer’s diet. This is baiting deer, not supplementing them. Baiting in this manner should not cause corn toxicity in deer.

Homeowners should not SUDDENLY pour a 50 pound sack of feed behind their house to feed cold, hungry deer that have not been exposed to corn. On the same note, hunters should not dump a pile of corn into the field since this could SUBSTANTIALLY alter a deer’s diet. Both of these scenarios end bad for the deer.

Digestive problems from the excessive intake of grain and resulting acidosis can lead to laminitis in white-tailed deer. Laminitis is caused by inadequate blood flow in the hoof which results in unusual foot growth and/or permanent lameness. Animals often die before the feet become involved. Avoid the disease of acidosis and corn toxicity in deer by NOT suddenly and substantially adding foods high in carbohydrates to their diets.

How to Get Deer Tested for CWD

Wondering how to get deer tested for CWD after the shot? Texas Parks and Wildlife Department (TPWD) will test your harvested deer for chronic wasting disease (CWD) during the upcoming deer hunting seasons. They start on October 3 for archery hunters and properties participating in TPWD’s Managed Lands Deer Permit (MLDP) Program.

CWD was recently found in two captive deer breeding facilities, one in Medina County and the other in Lavaca County. As a result, TPWD will increase efforts to strategically sample hunter harvested deer during the 2015-16 hunting season.

Testing Deer for CWD

Whitetail and mule deer hunters are encouraged to assist with this statewide monitoring effort by voluntarily submitting CWD samples for testing this fall. TPWD biologists will collect and submit samples to the Texas A&M Veterinary Diagnostic Lab at no cost to the hunter. Tissue samples from the heads of harvested deer must be collected within 24 hours of harvest, up to 48 hours if kept chilled. It is very important that the deer head not be frozen.

Since 2003, TPWD biologists have been monitoring the state’s free-ranging deer population for CWD. Using statistical sampling tables commonly used by animal disease experts, biologists set a sampling goal that would detect the disease with 95 percent confidence if at least one out of every 100 deer was infected.

Thus far, biologists have collected nearly 30,000 samples from hunter-harvested deer across Texas’ eight ecological regions, in most cases surpassing 95 percent confidence standards. To date, CWD has not been found in Texas free-ranging white-tailed deer.

CWD Sampling Based on Risk

The sampling strategy for the 2015-16 hunting season is being refined to target CWD disease risk levels within the state’s 33 unique Resource Management Units (RMU). These RMUs  are wildlife conservation areas that TPWD uses for all other deer management decisions. Criteria for establishing risk levels include factors such as deer density, susceptible species importation history, proximity to a CWD-positive site, etc.

Sampling goals will rely upon hunter harvest submissions ranging from 60 to 433 (lowest to highest risk) deer for each RMU, and if biologists can achieve these goals, will result in excess of 7,000 samples. TPWD will also specifically target sampling/testing efforts within a 5-mile radius around the CWD index facility in Medina County to determine the prevalence and geographic extent of the deer disease in that specific area.

“In the wake of our increased concern about CWD in Texas we are ramping up our sampling effort statewide,” said Mitch Lockwood, TPWD Big Game Program Director. “We will be collecting samples from deer and elk, and other cervid species, in every county where deer hunting occurs.”

How to Get Deer Tested

Hunters wishing to submit CWD samples from harvested mule and white-tailed deer for testing should contact the local TPWD biologist for the county. Biologists will provide information on how to get deer tested for CWD. In addition, biologists will provide a CWD sample receipt hunters can use to track test results online. TPWD anticipates test results could take 3-4 weeks to process.

In some cases, biologists may request to retain the entire deer head for later sample collection; a resource document will be given to the hunter as proof of sex in those instances. More information about the disease, CWD testing of harvested deer, safe carcass handling tips and deer processing precautions can be found here.