Veterinary Quarterly REVIEW Extension Veterinary Medicine College of Veterinary Medicine & Biomedical Sciences Volume 24, Number 4 Winter 2008 2009 Department of Large Animal Clinical Sciences, CVM, TAMU, College Station, Texas 77843 This is number ninety-five 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 BEEF AND DAIRY CATTLE PRACTICE Risk of Polioencephalomalacia with Distillers Grains Distillers grains are widely available as feed for livestock because of the recently established ethanol fuel industry. Distillers grains (DG) were originally named for being the byproducts left over from the liquor distilling industries. When corn or other grains are used in this process, about 28 percent remains as spent grains. If the solubles remaining after distillation are added back to the spent grains, it is called distillers grains with soluble (DGS). Both DG and DGS can be fed in a wet or dry form (WDG, DDG, WDGS, DDGS). These feeds are very high in energy, protein and some minerals. The sulfur content varies depending on the processing techniques used. This has been a problem in the livestock feeding industry, particularly with cattle. Excess amounts of sulfur cause polioencephalomalacia, whose clinical symptoms may be blindness and/or circling. If there is sulfur in other feedstuffs or in water, there is an additive effect with the sulfur in the distillers grains. Corn gluten and molasses products also have varying sulfur levels. In this issue If these products make up very much of the concentrate ration, they should be tested for sulfur levels before feeding. One laboratory that tests for sulfur in feedstuffs is Servitech; the Web site is www.servitechlabs.com/. From Distiller s Grains Polioencephalomalacia, Animal Health Update newsletter, Center for Veterinary Health Sciences, Oklahoma State University, Fall 2008. 1. Risk of Polioencephalomalacia with Distillers Grains 2. Texas Cattle Trichomoniasis Program Adopted: Interstate Rules Effective April 1, 2009; In-State Rules Effective Jan. 1, 2010 3. A Practical Treatment for Urolithiasis in Goats 4. Know Your Grasses Available 5. Veterinary Continuing Education Seminars, 2009, Texas A&M University 6. New Texas Coral Reefs Book Available 7. Feline Bartonellosis and Cat Scratch Disease 8. Quantification of the Association between Intervertebral Disk Calcification and Disk Herniation in Dachshunds 9. Contagious Equine Metritis-Infected Stallion Confirmed in Texas 10. American Association of Swine Veterinarians and National Pork Board Revise Swine Euthanasia Guidelines 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
Texas Cattle Trichomoniasis Program Adopted: Interstate Rules Effective April 1, 2009; In-State Rules Effective January 1, 2010 Beginning April 1, 2009, breeding bulls entering Texas from any other state must be no more than 24 months old and certified as virgins, or they must have tested negative for cattle trichomoniasis within 30 days before entry. The entry requirements are part of a regulatory package adopted by the Texas Animal Health Commission (TAHC) to address trichomoniasis, a venereal disease of cattle that causes infertility and abortions and results in extended breeding seasons and diminished calf crops. The disease is economically important to livestock producers. Cattle trichomoniasis is not a human health issue. Industry members had significant input into the development of these regulations, said TAHC Commissioner Coleman Locke, who represents the beef industry on the commission and headed the Trichomoniasis Working Group, comprising producers, market operators, veterinarians, laboratory representatives and educators. The 74 comments we received from associations and individuals regarding the proposed regulations were reviewed carefully, and adaptations to the proposed rules were made in the adopted regulations to make the program workable for the producers. We have worked for months with industry members, veterinarians and the working group to gather information and develop the proposed regulations. Following the conclusion of the comment period, we considered all comments to develop a viable, cost effective program, said Dr. Bob Hillman, executive director of the TAHC. Industry associations and producers asked us to work with them to develop a program that would stop the introduction and unchecked spread of this protozoal disease. At least 15 other states in the western half of the United States have developed similar trichomoniasis programs to address the disease in their states. The regulatory components of the Texas Cattle Trichomoniasis Program will focus only on breeding bulls, which, even when infected, continue to appear and act normally. Under the new regulations, trichomoniasis also becomes a reportable disease in Texas, which will give us more information on where and how much infection already is in the state, explained Dr. Hillman. There is no effective treatment or vaccine for bulls, and as they age, the surface of their organs becomes more hospitable to the protozoa, perpetuating the infection. Although the primary impact of the disease is on cows, which can become infected during breeding and abort, the cow herd is not included in the regulations. Most infected cows will clear the infection if they are given 120 to 150 days of sexual rest. A vaccine also can be administered to infected cows to help control the disease in the cow herd. Most of the producers who commented on the proposed rule and members of the working group recommended that the disease in the cow herd be managed through information and education efforts. Producers with infected herds should consult with their veterinarians to determine the most appropriate measures to employ to eliminate the disease from their herds. Virgin breeding bulls entering Texas must be identified and must be no more than 24 months old. A signed breeder s certificate must accompany the virgin breeding bull, and the information also must be included on the certificate of veterinary inspection. Other applicable tuberculosis or brucellosis entry requirements must be met, depending on the state of origin. Nonvirgin breeding bulls or bulls older than 24 months entering Texas must have tested negative for trichomoniasis within 30 days prior to entry. During the test period and before shipment, the bulls must have had no contact with female cattle. Like virgin bulls, the nonvirgin bulls must be officially identified with a breed registry tattoo or brand, a USDA metal ear tag, official RFID tag, official trichomoniasis ear tag from the state of origin, or other official identification. An animal must be accompanied by a completed trichomoniasis test document, certificate of veterinary inspection, and other routine health documents. The second phase of the program, which will address in-state movement of Texas breeding bulls, will go into effect January 1, 2010. It will require that breeding bulls changing possession within the state through sale, lease, exchange or any other means be certified as virgin bulls or have a negative test before the change of the possession. (No test or certification is required for bulls shipped or sold directly to slaughter.) Only one PCR (Real Time Polymerase Chain Reaction test) is required on nonvirgin bulls changing possession; alternatively, three consecutive culture tests, not less than 7 days apart, can be conducted. Breeding bulls must remain separated from female cattle during the testing. Negative test results will be valid for 30 days, but only if the tested breeding bulls continue to be separated from heifers or cows. A bull s virgin status can be extended to 30 months, which was requested by commenters, provided the breeder and the herd s accredited veterinarian certify on a breeder s certificate that the bull facility is sufficient to prevent contact with female cattle. The TAHC Commissioners delayed the implementation of the intrastate, or in-state movement requirements, to January 1, 2010, to provide time to 2 Veterinary Quarterly
certify veterinarians to perform all components of the trichomoniasis program, and to ensure producers are familiar with the disease, its implication to herd health, and the requirements for testing or certifying the virgin status of Texas breeding bulls undergoing change of possession, noted Dr. Hillman. We will be working closely with cattle industry organizations, Texas AgriLife Extension Service, the Texas Veterinary Medical Association and the Texas Veterinary Medical Diagnostic Laboratories to develop and deliver an effective information and education effort for cattle producers in Texas. We will be attending and making presentations at local, area and state producer and veterinary meetings to review the requirements and to ensure that producers are aware of the disease program. Dr. Hillman noted that samples for testing must be collected by accredited veterinarians certified to conduct cattle trichomoniasis work, and tests will be run at the Texas Veterinary Medical Diagnostic Laboratory (TVMDL). Seminars will be offered around Texas to certify accredited veterinarians, which will ensure that the collection methods, paperwork completion, sample submission, disease reporting and management of infected bull herds are uniform throughout the state, said Dr. Hillman. Payment for sample collection and laboratory costs will be the responsibility of the producer. Infected bulls will be restricted to movement for slaughter only, as there is no effective treatment for this disease, said Dr. Hillman. The remaining bulls in the herd will be held, isolated from female cattle until they are tested at least once more by PCR test or twice more by culture, with each culture conducted at least a week apart. If the remaining bulls test negative (each nonvirgin bull in an infected herd must have at least two consecutive negative RT PCR tests or at least three consecutive negative culture tests in order to be classified as negative), they are free to move. Producers who have encountered cattle trichomoniasis in their herds know how devastating this disease can be to their calf crops and production, stressed Dr. Hillman. This program is directly in response to producer and association requests for help to stop the spread of this insidious disease, and to stop the importation of infected bulls into the state. It is important to note that since this is an industry requested program, input from the cattle industry is critical to the effective functioning of the program. To this end, the rules contain provisions for the program to be reviewed annually by a broad based Trichomoniasis Review Working Group, which can make recommendations on changes or even abolishment of the program. By enacting the interstate requirements now, we can address the importation of disease immediately, he said. Delaying the intrastate regulations until the first of next year will ensure that everyone can be on board to attack this disease and protect their herds. From a February 27, 2009 news release, Texas Cattle Trichomoniasis Program Adopted, by Carla Everett, information officer, Texas Animal Health Commission, Box 12966, Austin, Texas 78711, Bob Hillman, DVM, executive director. For more information contact Carla Everett at 1-800-550-8242 ext 710 or ceverett@tahc.state.tx.us SHEEP AND GOAT PRACTICE A Practical Treatment for Urolithiasis in Goats A retrospective case study was conducted to review the outcome of ultrasound-guided cystocentesis and percutaneous injection of Walpole s solution for the treatment of male goats with urolithiasis. Twenty-five male goats were included in the study. Fourteen animals (56%) had complete urethral obstruction and 10 (40%) had partial obstruction. The severity of obstruction was not recorded in one goat. During initial examination, the urethral process was present and subsequently amputated in 18 of 24 animals (75%). Four of six animals without a urethral process at the time of admission had complete urethral obstruction. Walpole s solution was infused once in 18 (72%), twice in six (24%) and three times in one goat (4%). A range of 50 to 250 ml of Walpole s solution was infused into the bladder to achieve the target ph of 4 to 5. The urethra became patent in 20 treated goats (80%) and these were discharged. Five of the treated goats (20%) were euthanized because of persistent urethral blockage. Six of the 20 discharged goats (30%) were reexamined when urethral obstruction recurred; these were retreated with an infusion of Walpole solution. In four of the six re-treated animals, urethral obstruction resolved again. Two of the six were euthanized because of persistent obstruction. Researchers could not determine how much of the response was due to Walpole s solution alone, since concurrent treatments (including Flunixin meglumine and ammonium chloride administration and amputation of the urethral process) were performed in most cases. Also, the longterm success rate of Walpole solution could not be determined. Nevertheless, the results suggest that ultrasound-guided cystocentesis combined with percutaneous infusion of Walpole s solution may be a practical and cost-effective treatment in male goats with obstructive urolithiasis. From Use of Walpole s Solution for Treatment of Goats with Urolithiasis, J.J. Janke, J.B. Osterstock, K.E. Washburn, et al., Journal of the American Veterinary Medical Association, Volume 234, Number 2, January 15, 2009, 249-252. Veterinary Quarterly 3
GENERAL PRACTICE AQUATIC PRACTICE FELINE PRACTICE Know Your Grasses Available The popular Extension publication Know Your Grasses, by Barron S. Rector, is again available. Grasses are one of Texas most valuable natural resources. This publication will introduce you to the amazing variety of native and introduced grasses in Texas. Plants are arranged alphabetically by common name, with scientific names included for clarity and reference. Each grass is beautifully illustrated and carefully described, with information about the areas of the state which it can be found. Order your copy online at http:// agrilifebookstore.org. The cost is $14.95. New Texas Coral Reefs Book Available The first edition of SP-347, Texas Coral Reefs, is available (Jesse Cancelmo, August 2008, 134 pages, $25.00). The spectacular colors of reef fishes blaze from every page of this book. More than 30 coral reefs can be found just off the Texas coast; each teems with life, from ruby brittle stars to jackknife fish to hermit crabs and rays. The author takes you along as he explores the underwater wonderland. Order online at http://agrilifebookstore.org. Veterinary Continuing Education Seminars College of Veterinary Medicine & Biomedical Sciences Texas A&M University, 2009 *May 1 3...Annual Feline Medicine Symposium (Dr. John August) *June 5 7...18th Annual Food Animal Conference (Chair to be named) *July 24 26...Practical Dentistry for Small Animal Practitioners (Dr. Bert Dodd) *August 7 9... Orthopedics Conference (Dr. Don Hulse) *August 21 23...Oncology/Cytology Conference (Dr. Heather Wilson) *October 2 4... Annual Clinical Neurology Conference (Dr. John Levine) *October 16 18...Annual Equine Reproduction Symposium (Dr. Dickson Varner) *October 23 25...Annual Equine Conference (Chair to be named) *November 6 8... Small Animal Emergency Medicine & Critical Care (Dr. David Nelson) *November 13 14...Small Animal Anesthesia Conference (Dr. Elizabeth Martinez) *December 4 6... Annual Exotic Pets Conference (Dr. Sharman Hoppes) *Confirmed Calendar is subject to revision. For more information on these programs of self-study and personalized continuing education opportunities, please call 979-845-9102; (fax) 979-862-2832; or e-mail ceoffice@cvm.tamu.edu. Visit our Web site at http://www.cvm.tamu.edu/vtce. From the Office of Veterinary Continuing Education, Texas Veterinary Medical Center, College Station, Texas. Feline Bartonellosis and Cat Scratch Disease Bartonella species are important emerging zoonotic pathogens. Transmission of these organisms in nature may be much more complex than is currently thought. Cats can be infected with five Bartonella species, including Bartonella henselae, Bartonella clarridgeae, Bartonella bovis, Bartonella koehlerae and Bartonella quintana. In addition to cats, humans and many domestic and wild animals (including bovine, canine and rodent species) can serve as chronically infected reservoir hosts for various intra-erythrocytic Bartonella species. A number of arthropod vectors, including biting flies, fleas, keds, lice, sand flies and potentially ticks, have been implicated in the transmission of various Bartonella species to animals or humans. In the reservoir host, Bartonella species cause chronic intra-erythrocytic and vascular endothelial infections, with relapsing bacteremia documented in experimentally infected cats. Although the immunopathology induced by Bartonella infection requires additional study, the organisms can localize to the heart valve (endocarditis); cause granulomatous inflammation in lymph nodes, liver or spleen; induce CNS dysfunction with or without cerebrospinal fluid changes; and may contribute to inflammatory polyarthritis. Hematological abnormalities are infrequent, but thrombocytopenia, lymphocytosis, neutropenia and eosinophilia have been reported in Bartonella henselaeinfected cats. Serology, PCR and culture can be used to support a diagnosis of feline bartonellosis, but because of the high rate of subclinical infections among various cat populations, documenting the cause in an individual cat is difficult, if not impossible. 4 Veterinary Quarterly
As fleas are involved in transmission among cats, the use of acaracides to eliminate fleas from the environment is critical to decreasing the risk of Bartonella henselae transmission from cats to humans. From Breitschwerdt, E.B., Feline Bartonellosis and Cat Scratch Disease, Veterinary Immunology and Immunopathology, 123:1/2, pp. 167-171, 2008, from the Veterinary Science Database, CBI, as reported in Animal Health Spectrum newsletter, Volume 20, No. 1, Winter 2009, Extension Veterinary Medicine, Mississippi State University Extension Service. CANINE PRACTICE Quantification of the Association between Intervertebral Disk Calcification and Disk Herniation in Dachshunds A longitudinal study was conducted to quantify the association between intervertebral disk calcification and disk herniation in dachshunds. Of 61 dachshunds that had been radiographically screened for calcification of intervertebral disks at 2 years old in other studies, 37 had survived to the time of the present study and were 8 years old or older; 24 others had not survived. Radiographic examination of the 36 surviving dogs was performed and information on the occurrence of disk calcification at 2 years of age was obtained from records of all dachshunds. A questionnaire given to owners obtained information on the occurrence of disk herniation between 2 and 8 years of age. Associations between numbers of calcified disks and disk herniation were analyzed with maximum likelihood logistical regression. Results: Disk calcification at 2 years of age was a significant predictor of clinical disk herniation. The number of calcified disks in the full vertebral column was a better predictor than the number of calcified disks between vertebrae T10 and L3. Numbers of calcified disks at 8 or more years of age and at 2 years of age were significantly correlated. Practical importance: Because of the high heritability of disk calcification, it is possible that an effective reduction in the occurrence of severe disk herniation in dachshunds could be obtained by selective breeding against high numbers of calcified disks at 2 years of age. A radiographic screening program is ongoing in Denmark. The Danish Dachshund Club recommends breeding dogs with two or fewer calcified disks but not dogs with more than four calcified disks. Dogs with three or four calcified disks may be used only for strategic breeding, such as having only one or two litters with progeny screening before further breeding. The results of this present study support the Danish breeding recommendations. From Quantification of the Association Between Intervertebral Disk Calcification and Disk Herniation in Dachshunds, V. J. Jensen, S. Beck, K.A. Christensen, et al., Journal of the American Veterinary Medical Association, Volume 233, Number 7, October 1, 2008, 1090-1095. EQUINE PRACTICE Contagious Equine Metritis- Infected Stallion Confirmed in Texas The Texas Animal Health Commission (TAHC) reports that laboratory tests have confirmed contagious equine metritis (CEM), a highly contagious venereal disease of horses, in a stallion in Texas. The Texas-born quarter horse had spent the 2008 breeding season in Kentucky, where CEM was detected in a stallion during routine testing in mid December. As of January 15, nine infected stallions had been detected: four in Kentucky, three in Indiana, and one each in Wisconsin and Texas. All of the infected stallions have epidemiological links to one or more CEM infected equine during the 2007 or 2008 breeding season. State and federal authorities are seeking the source of the infection. At least 38 states are involved in an epidemiological investigation and testing of about 275 horses that may have been exposed to CEM through natural breeding or artificial insemination. The disease can be spread among stallions if strict biosecurity measures are not maintained during the collection of semen. CEM is not routinely spread through casual contact or shared boarding facilities, and horses can be treated with disinfectants and antibiotics to wipe out the infection. The movement of potentially exposed and infected horses is being restricted by state animal health authorities until the animals test negative for the disease or are treated and certified as CEM negative. The TAHC is working with accredited private veterinary practitioners to test another stallion and 21 mares that may have been exposed to CEM. In some cases, CEM may cause infected mares to abort. CEM is not known to affect humans. The equine disease was first detected in the United States in 1978, then again in 1979. In both instances, the limited outbreaks were eradicated. Additional information may be found on the USDA s Web site at http://www.aphis.usda.gov/news room/hot_issues/cem/index.shtml From a January 15, 2009, news release, CEM- Infected Stallion Confirmed in Texas, by Carla Everett, information officer, Texas Animal Health Commission, Box l2966, Austin, Texas 78711, (800) 550 8242, FAX (512) 719 0719; Bob Hillman, DVM executive director. For more information, contact Carla Everett at 1 800 550 8242, ext. 710, or ceverett@tahc.state.tx.us Veterinary Quarterly 5
SWINE PRACTICE American Association of Swine Veterinarians and National Pork Board Revise Swine Euthanasia Guidelines Members and staff of the American Association of Swine Veterinarians and the National Pork Board recently reviewed and revised the document NPB-04259, On Farm Euthanasia of Swine Recommendations for the Producer. The new, 20-page booklet is designed to help producers make appropriate decisions regarding euthanasia of swine. It describes methods of euthanasia recommended for different sizes of pigs and explains the factors to consider when selecting a method. Copies are available in pdf format or print. Go to http://www.porkstore. pork.org to order. From AASV Staff, American Association of Swine Veterinarians, 902 First Avenue, Perry, Iowa 50220, PHONE (515) 465-5255, FAX (515) 465-3832, E-mail aasv@aasv.org, WEB http://www. aasv.org; and National Pork Board, P.O. Box 9114, Des Moines, Iowa 50306, PHONE (515) 223-2600, FAX (515) 223-2646, WEB http://www.pork.org.