Veterinary Quarterly. Extension Veterinary Medicine College of Veterinary Medicine & Biomedical Sciences

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1 Veterinary Quarterly REVIEW Extension Veterinary Medicine College of Veterinary Medicine & Biomedical Sciences Volume 24, Number 3 Fall 2008 Department of Large Animal Clinical Sciences, CVM, TAMU, College Station, Texas This is number ninety-four of a continuing series of multispecies quarterly reviews and practice tips for veterinarians in Texas. Information in the Veterinary Quarterly Review is intended to be timely, concise and of practical value. Ideas and input from practicing veterinarians are encouraged Sources of abstracts, articles or practice tips will be credited. Questions/comments may be directed to blawhorn@cvm.tamu.edu. Bruce Lawhorn Visiting Professor, Swine Practice F.C. Faries, Jr. Extension Program Leader for Veterinary Medicine Steve Wikse Professor and Extension Veterinarian Beef Cattle BEEF AND DAIRY CATTLE PRACTICE New Efficacy Information on Vaccinating Calves with Persistent Maternal Immunity Current research confirms that calves can often be primed to develop a protective immune response to later challenge when vaccinated for the first time in the face of maternal antibody (IFOMA). Vaccination IFOMA activates pathogen-specific T cells in the absence of seroconversion following the first vaccination. Protection of calves vaccinated IFOMA has been shown by in vitro and ex vivo assays of immune function, by experimental challenge of vaccinated calves, and, in a small number of cases, by field trials that show decreased rates of naturally occurring disease or infection. Although more precise guidelines must await further research, data so far indicate that vaccination IFOMA can protect calves from disease when they are exposed to infectious agents after maternal antibodies have disappeared, in at least some cases. Vaccination IFOMA may be a worthwhile and cost-effective practice when nursing or post-weaning calves are at In this issue a reasonably high risk of diseases for which effective vaccines are available. More field studies are needed to confirm the promising findings of laboratory studies. Abstracted from Woolums, A.R., Vaccinating Calves: New Information on the Effects of Maternal Immunity, as reported in Proceedings of the American Association of Bovine Practitioners, Volume 40, September 2007, pp New Efficacy Information on Vaccinating Calves with Maternal Immunity 2. Proposed Regulations on Texas Cattle Trichomoniasis Program 3. California Passes Proposition 2 4. Oral Transmission of Circovirus Type 2 to Susceptible Pigs by Contaminated Pork Muscle and Bone Marrow 5. Deer Hunters Reminded of South Texas Tick Quarantine Restrictions 6. First Live Animal Test for Chronic Wasting Disease in Elk Developed 7. New Rules for the Movement of Live Feral Swine Adopted October 1, 2008 by the Texas Animal Health Commission 8. Giant Salvinia an Impending Calamity for Texas Lakes 9. Fishes of the Gulf of Mexico Recently Updated and Available 10. Veterinary Continuing Education Seminars, 2009, Texas A&M University 11. Top 10 Human Drug Types Causing Accidental Dog and Cat Poisoning Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin. The Texas A&M System, U.S. Department of Agriculture, and the County Commissioners Court of Texas Cooperating

2 Proposed Regulations on Texas Cattle Trichomoniasis Program Ranchers, cattle owners, veterinarians and other interested persons are encouraged to comment on Texas proposed regulations to control Trichomoniasis, or trich, a venereal disease of cattle that causes the early death of fetuses and abortions. The disease results in infertility in cows and extended breeding seasons in a herd. The comment period for the Texas Animal Health Commission s (TAHC) proposed regulations ends January 30, Trich infection often occurs when a producer unknowingly introduces an infected bull into the herd, and this bull infects cows during breeding. Likewise, infected cows can transmit the disease to clean bulls, creating a cycle of disease. Cattle experts say that the extended breeding seasons and loss of part of the calf crop can cause up to a 20 percent loss of herd income, said Dr. Bob Hillman, Texas state veterinarian and executive director of the TAHC. In the absence of a national trich control or eradication program, all western states, except Kansas and Texas, have taken regulatory action to prevent the introduction of infected bulls, and to control the spread of this cattle disease within their states, said Hillman. After being approached by the Texas cattle industry regarding the need for Texas trich regulations, the TAHC appointed a working group of cattle producers, veterinarians, university personnel and others to study and make recommendations for such regulations. The proposed Texas trich program focuses on breeding bulls, he said. According to Hillman, the Texas Trichomoniasis Program would roll out in two stages. The first stage, which could go into effect in late March 2009, would place new requirements on bulls entering Texas from other states. Breeding bulls would have to be officially certified as virgin bulls or have a negative trich test within 30 days of entering Texas. Bulls could be certified as virgins until they were about 18 months old, as evidenced by the eruption of permanent incisors and a breeder s statement that the animal had not been commingled with heifers or cows. Bulls entering Texas without such certification or negative trich tests would be restricted to sale or movement for slaughter only. Hillman explained that bulls are tested by culturing samples for the trich organism. In nearly all states with regulations, this must be done by accredited private veterinary practitioners and laboratories approved to do trich tests, said Hillman. The system specified for Texas is the InPouch, which allows the sample to be incubated and microscopically examined in the pouch. The Real Time Polymerase Chain Reaction test (RT-PCR) also be can run on the incubated sample. According to the proposed regulations, all the non-virgin bulls in a herd could be tested at the same time. If results were negative, this single test would be sufficient for importing any of the bulls in the herd, said Hillman. Individual bulls would have to have three consecutive negative culture tests, at least 7 days apart, or two negative RT-PCR tests performed at least 7 days apart. Repeated tests are needed for individual bulls because of the difficulty of collecting the tiny trich protozoa from the surface folds of the bull s reproductive organs, whereas testing all bulls in a herd should, statistically, reveal the disease with one test. Hillman noted that there is no effective treatment for infected bulls. Culling them is the only way to halt the spread of disease. Most infected cows can recover from the disease if the animals are given three to four heat cycles of sexual rest. A small percentage of cows will not clear, and these should be culled. A cow s disease status can be identified through a veterinary examination of the reproductive tract. Under the proposed regulations, trich would become a reportable livestock disease in Texas, requiring that both negative and positive test results be reported within 48 hours. Acquiring negative data is as important as positive results when determining the prevalence and distribution of the disease within the state. This information would be invaluable for determining the future direction of the program, Hillman explained. The second phase of the proposed Texas Trichomoniasis Program would be effective no earlier than September Before changing ownership in Texas, breeding bulls would have to be officially certified as virgin bulls or be tested for trich. Infected bulls would be restricted to slaughter or movement through a livestock market to slaughter. The negative trich tests for Texas-origin bulls would be valid for 150 days provided the animals were not commingled with female cattle from the date of the test to the sale date. The Texas Veterinary Medical Diagnostic Laboratories in College Station and Amarillo would serve as the official laboratories for the program. Texas accredited veterinarians could be certified to collect the samples. A bull s owner or seller would be responsible for costs associated with virgin certification or testing. Laboratory fees are about $5 for the InPouch culture test and $25 for the RT-PCR test. To ensure that the trich program continues only as needed, the TAHC commissioners added a final, very important caveat to the proposed regulations, said Dr. Hillman. The program would undergo an annual review by a Trichomoniasis Program Review Working Group, which would consist of representatives from the 2 Veterinary Quarterly

3 cattle industry, veterinary colleges, veterinarians and the TAHC. Representatives from TAHC are available to discuss trich and the proposed program regulations at industry, producer or veterinary meetings, classes or association gatherings. To arrange for a speaker, contact the nearest TAHC area office or call the TAHC Public Information Office at , ext 710. A fact sheet and the text of the proposed TAHC regulations are posted on the TAHC Web site. Or, you can request this information by contacting the TAHC at comments@tahc. state.tx.us or , ext written comments about the proposed trich program regulations to comments@tahc.state. tx.us; fax them to ; or mail them to TAHC Comments, Box 12966, Austin, TX From a November 24, 2008, news release, Comments Sought on Proposed Cattle Trich Program for Texas, by Carla Everett, information officer, Texas Animal Health Commission, Box l2966, Austin, Texas For more information contact Carla Everett at ceverett@tahc.state.tx.us. SWINE PRACTICE California Passes Proposition 2 A proposal that would ban modern housing systems for gestating sows, egg-laying hens and veal calves by 2015 was approved November 4, 2008, by 63 percent of California voters. Similar laws for swine and veal have previously been passed by voters in Florida, Arizona, Colorado and Oregon. California is the first of these five states to require that all egg-producing hens be kept in more spacious enclosures or be free to roam in a hen house. Most swine and veal producers have already expanded their pen sizes so California s law will have the most impact on the poultry industry. In approving the initiative, voters rejected the arguments of Governor Arnold Schwarzenegger, the agricultural industries and the American Veterinary Medical Association. Adapted from California Passes Proposition 2, American Sheep Industry Weekly, November 7, Oral Transmission of Circovirus Type 2 to Susceptible Pigs by Contaminated Pork Muscle and Bone Marrow A recent study demonstrated that susceptible pigs can be infected with circovirus type 2 when they consume uncooked, infected pork lymphoid tissues, bone marrow and skeletal muscle. This means that pork products can introduce PCV2 isolates into a swine farm. This research reemphasizes the importance of properly disposing of leftover human food products containing pork meat scraps. Opriessnig T., Patterson A.R., Xiang-Jin M., et al. Porcine Circovirus type 2 in Muscle and Bone Marrow is Infectious and Transmissible to Naïve Pigs by Oral Consumption. Veterinary Microbiology, Volume 133, Issues 1-2, January 1, 2008, 54-64, as reported in American Association of Swine Veterinarians (AASV) News Archive, November 25, 2008; and Bruce Lawhorn, DVM, MS, Visiting Professor, Swine Practice, Food Animal Section, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas WILDLIFE AND EXOTIC PRACTICE Deer Hunters Reminded of South Texas Tick Quarantine Restrictions State officials are reminding hunters and meat processors in South Texas that additional precautions are required when handling deer carcasses because of concerns about the spread of fever ticks in the region. The general deer hunting season opened Nov. 1. Portions of Zapata, Starr, Jim Hogg, Maverick, Dimmit and Webb counties are under preventive quarantine for livestock by the Texas Animal Health Commission (TAHC) because of increased numbers of fever ticks outside the permanent quarantine zone along the Rio Grande border. The entire quarantine area covers more than 1 million acres. If you are hunting in these counties, contact the land owner or manager to determine the current fever tick status. Cattle, horses, white-tailed deer, nilgai and elk can act as hosts for the tick. If not contained, fever ticks will continue to spread northward outside the permanent fever tick quarantine area and could become re-established in other areas of Texas and throughout much of the south, southeast and parts of California. We re telling hunters to use common sense and take precautions when handling and transporting deer taken on ranches within the quarantine zone, said Mike Berger, Texas Parks and Wildlife Department director of wildlife. According to the TAHC, fever ticks are unlikely to kill deer, but can affect their condition and general well-being. It is safe to eat venison from fever tick-infested deer. Deer harvested on infested, exposed, adjacent and check premises must be inspected, treated and permitted before they can be removed from the premises. If you kill a deer on other properties within the temporary quarantine areas, you have three options: 1. Remove the hide completely and leave it on the ranch. If the skull is needed for proof of sex, seal it in a bag, then dispose of it away from livestock or wildlife after the carcass is processed. 2. Freeze the hide for 24 hours. Veterinary Quarterly 3

4 3. Have the hide/cape inspected and treated by the U.S. Department of Agriculture s Fever Tick Force before removing it from the ranch. A permit for movement issued by a representative of the TAHC must accompany the shipment of the hide and cape. There is too much at stake here to take a chance on inadvertently carrying this deadly parasite outside the quarantine zone and we are asking hunters to be vigilant to help keep this tick from spreading, Berger stressed. Fever ticks can carry and transmit a protozoa, or tiny blood parasite, that destroys red blood cells, causing the deadly livestock disease Texas Fever. Cattle are highly susceptible to Texas Fever, which may kill up to 90 percent of infected cattle. It took more than 50 years to eradicate fever ticks from the U.S., said Dr. Bob Hillman, TAHC executive director and Texas state veterinarian. We have taken extraordinary precautions against expansion of fever tick infestation into other counties or other areas of the Texas. Compliance with these measures is extremely important to prevent the spread of this dangerous tick. A permanent fever tick quarantine zone runs through eight South Texas counties along the Rio Grande to prevent the reintroduction of the ticks into Texas and the U.S. Additional information on fever ticks may be found on the TAHC Web site at tx.us. From an October 22, 2008, news release, Deer Hunters Reminded of South Texas Fever Tick Quarantine, by Carla Everett, public information officer, Texas Animal Health Commission, Box 12966, Austin, Texas 78711, , FAX , and from Texas Parks and Wildlife. For more information contact Carla Everett at ceverett@tahc.stste.tx.us. First Live Animal Test for Chronic Wasting Disease in Elk Developed Researchers from the U.S. Department of Agriculture s Animal and Plant Health Inspection Service (USDA/APHIS) and Colorado State University (CSU) recently completed their third year of evaluating and validating the first live rectal tissue biopsy method for detecting chronic wasting disease (CWD) in captive and wild elk. To date, researchers have collected more than 1,500 biopsies from captive elk in Colorado and used the technique to find 15 elk that were positive for CWD. This live test appears to be nearly as accurate as proven post-mortem diagnostic tests. The key advantage to the rectal biopsy test is that it can be performed on live animals. Until now, there was no practical live test for CWD in elk, said research biologist Dr. Kurt VerCauteren with APHIS Wildlife Services (WS) National Wildlife Research Center (NWRC). With this technique we can detect CWD in animals not showing any signs of the disease and, thus, remove them so they are not left to infect other individuals and further contaminate the environment. The research is a collaborative effort between APHIS WS and Veterinary Services programs, the Agricultural Research Service, and the Colorado State University Veterinary Diagnostic Laboratory within the College of Veterinary Medicine and Biomedical Sciences. Most of the research was conducted on the Velvet Ridge Elk Ranch, owned by Dennis and Stephanie White, near Fort Collins, Colorado. In 2002, an elk on this ranch was confirmed to have CWD and since then the Whites have worked closely with NWRC and other collaborators to learn more about CWD and develop methods of managing it in captive and wild settings. CWD is a transmissible spongiform encephalopathy that causes abnormal proteins to accumulate in the central nervous system and lymphatic systems of infected animals. Symptoms are a degenerative lack of control, a wasting-away decline, and death. There is no cure for CWD. The disease is reported in captive and free-ranging mule deer, whitetailed deer, elk and moose. An estimated 12,000 to 14,000 captive elk have been killed in the western U.S. and Canada in the past 7 to 8 years to control CWD. Several thousand free-ranging mule deer, white-tailed deer and elk also have been killed in attempts to reduce the disease in the wild. The NWRC is the research arm of USDA s WS program. It is the federal institution devoted to resolving problems caused by the interaction of wild animals and society. The center develops practical ways to resolve these problems and maintain the quality of the environment shared with wildlife. To learn more about NWRC, visit wildlife_damage/nwrc/. From a May 30, 2008, news release, USDA and Colorado State University Researchers Develop First Live Test for Chronic Wasting Disease in Elk, by Gail Keirn and Carol Bannermann , USDA/APHIS Legislative and Public Affairs, 4700 River Road, Riverdale, Maryland, , , usda.gov. New Rules for the Movement of Live Feral Swine Adopted by the Texas Animal Health Commission New rules for the movement of live feral swine were adopted by the Texas Animal Health Commission (TAHC) on October 1, The rules state that after trapping or capture by some other means, live feral hogs can be legally moved or transported from private property to one of only 4 Veterinary Quarterly

5 three locations: 1) a TAHC-approved holding facility, 2) a TAHC-approved hunting preserve (boars and barrows only with individual ID tag or mark; gilts and sows cannot be legally moved to a hunting preserve), or 3) a legally established and governmentinspected slaughter facility. Note that a TAHC-approved hunting preserve must be enclosed in swine-proof fencing (much debate still on swine-proof fencing!) and have a hunting lease license issued by Texas Parks and Wildlife. Also, the boars and barrows to be released must be individually identified. The TAHC is currently working on the type of tag or other ID to be attached to male feral swine before release within a hunting preserve. The TAHC does not charge any fees for permits. These new TAHC regulations affect only the transporting and holding of live feral swine. They do not affect current laws or rules governing hunting, live-trapping or otherwise harvesting feral swine for personal use on private property. Also, as long as the animal is dead when it leaves private property, these new TAHC transportation and holding regulations do not apply. Many comments were received before the TAHC adopted these rules. For an in-depth discussion of the history of these regulations, the comments and TAHC response to comments for the current new rules, and the detailed new rules themselves, go to animal_health/swine/2008aug_feral SwineRegulationAndComments.pdf. AQUATIC PRACTICE Giant Salvinia an Impending Calamity for Texas Lakes Salvinia molesta, better known as giant salvinia, is a non-native, freefloating plant that can reproduce uncontrollably and double in surface area size each week. Giant salvinia plants form dense mats that can cover the surfaces of entire lakes of any size. Such dense cover blocks sunlight, reduces oxygen levels, destroys fisheries and wildlife habitat, and clogs the cooling inlets of powergenerating plants. Giant salvinia is being recognized as an impending disaster for southern lakes in the U.S. It is already a problem at Toledo Bend Reservoir, Sam Rayburn Reservoir, B.A. Steinhagen Lake, Center City Lake, Lake Texana, Sheldon Lake, Lake Conroe, Brady Branch Reservoir and Caddo Lake, and it is slowly spreading west. Giant salvinia is most commonly spread by sticking to boat trailers and being transported to a new body of water. It is a Class C misdemeanor, punishable by a fine of up to $500 per plant, to possess or transport giant salvinia in Texas. The Texas Agrilife Extension publication L-5432, Salvinia, is a color poster that illustrates this plant pest and shows the weevil that is used as one method of controlling it. This poster is available for $5.50 from the Texas AgriLife Bookstore at agrilifebookstore.org. Condensed from A Monstor is Loose in Caddo Lake by Jack Canson and Kent Barker, Texas CO-OP Power, November 2008, pp Fishes of the Gulf of Mexico Recently Updated and Available The second edition of SP-341, Fishes of the Gulf of Mexico, is now available (H. Dickson Hoese and Richard H. Moore, August 2008, 424 pages, $19.00). This book has long been the premiere reference for identifying fish of coastal waters. It includes descriptions of 539 species and their locations. To help the reader identify fish species, there are 225 color photographs and identification keys for groups of fishes. Sections on ecology and conservation review the results of recent and ongoing studies. Order online at Veterinary Continuing Education Seminars College of Veterinary Medicine & Biomedical Sciences Texas A&M University, 2009 *February 6 8, th Annual Veterinary Technician Conference (Ms. Lori Atkins and Candise McKay) *February 20 22, Pain and Physical Rehabilitation Seminar (Dr. Gwendolyn Carroll) *May 1 3, Annual Feline Medicine Symposium (Dr. John August) *June 5 7, th Annual Food Animal Conference (chair to be named) *July 24 26, Practical Dentistry for Small Animal Practitioners (Dr. Bert Dodd) *Confirmed. Calendar is subject to revision. For more information on these programs of self-study and personalized continuing education opportunities, please call ; (fax) ; or ceoffice@cvm.tamu.edu. Visit our Web site at From the Office of Veterinary Continuing Education, Texas Veterinary Medical Center, College Station, Texas. Veterinary Quarterly 5

6 CANINE AND FELINE PRACTICE Top 10 Human Drug Types Causing Accidental Poisonings of Dogs and Cats In 2007, the ASPCA Animal Poison Control Center received 89,000 calls related to pets ingesting overthe-counter and prescription medications. To help you prevent an accident, ASPCA poison control experts have created a list of the top 10 human medications or medication groups that most often poison dogs and cats. The ASPCA Animal Poison Control Center s 24-hour hotline is Remember to advise your clients to keep all medications stored in bathroom cabinets and far from curious cats and dogs. NSAIDs NSAIDs (non-steroidal anti-inflammatory drugs) like ibuprofen or naproxen are the most common cause of pet poisoning in small animals. They can cause serious problems even in minimal doses. Pets are extremely sensitive to their effects, and may experience stomach and intestinal ulcers and, in the case of cats, kidney damage. Antidepressants Antidepressants can cause vomiting and lethargy and certain types can lead to serotonin syndrome a condition marked by agitation; elevated body temperature, heart rate and blood pressure; disorientation; vocalization; tremors and seizures. Acetaminophen Cats are especially sensitive to acetaminophen, which can damage red blood cells and interfere with their ability to transport oxygen. In dogs, it can cause liver damage and, at higher doses, red blood cell damage. Methylphenidate (for ADHD) Medications used to treat ADHD (Attention Deficit Hyperactivity Disorder) in people act as stimulants in pets and can dangerously elevate heart rates, blood pressure and body temperature, and cause seizures. Fluorouracil Fluorouracil an anti-cancer drug is used topically to treat minor skin cancers and solar keratitis in humans. It is rapidly fatal to dogs, causing severe vomiting, seizures and cardiac arrest even in dogs that have chewed on discarded cotton swabs used to apply the medication. Isoniazid Often the first line of defense against tuberculosis, isoniazid is particularly toxic for dogs because they don t metabolize it as well as other species. It can cause a rapid onset of severe seizures that may ultimately result in death. Pseudoephedrine Pseudoephedrine is a popular decongestant in many cold and sinus products. It acts like a stimulant if accidentally ingested by pets. In cats and dogs it causes elevated heart rates, blood pressure and body temperature, as well as seizures. Anti-diabetics Many oral diabetes treatments including glipizide and glyburide can cause a major drop in blood sugar levels of affected pets. Clinical signs of ingestion include disorientation, lack of coordination and seizures. Vitamin D derivatives Even small exposures to Vitamin D analogues like calcipotriene and calcitriol can cause life-threatening spikes in blood calcium levels in pets. Clinical signs of exposure including vomiting, loss of appetite, increased urination and thirst due to kidney failure often don t occur for more than 24 hours after ingestion. Baclofen Baclofen is a muscle relaxant that can impair the central nervous systems of cats and dogs. Some symptoms of ingestion include significant depression, disorientation, vocalization, seizures and coma, which can lead to death. Adapted from the American Society for the Prevention of Cruelty to Animals (ASPCA) Web site, October 17, 2008; PageServer?pagename=pro_apcc_medications. 6 Veterinary Quarterly

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