- Email: [email protected]
Bovine papilloma virus and equine sarcoids
environmental parameters will provide safeguards for 2002 and future years. This will require detailed planning and coordination with farm managers, veterinarians, scientists, and analytical laboratories. The remainder of 2001 will allow time to implement a plan providing reassurance for the success of the 2002 breeding season. Dr. Roberta Dwyer, from the University of Kentucky, has been in charge of a MRLS epidemiological study. She says that at first glance, conducting a survey should be an easy task: ask the questions you want answers to, and tally the results. Surveying with short, five-question surveys, as was done on May 7 to members of the Kentucky Thoroughbred Farm Managers' Club, was a straightforward job: 159 e-mailed or faxed responses were returned by 10 a.m., May 10, with results disseminated the next evening. Volunteer Dr. John Walker spent some 10 hours collecting and analyzing the data via computer software. Designing a survey to scientifically identify and analyze potentially multiple risks on farm, pasture, and individual animal bases is extremely complex. Wording survey questions is an art, since the final results must have numerators and denominators for both percentage and comparative analysis. An outbreak emergency situation is not the time to learn how to design and analyze surveys. Dr. Dwyer said, "We asked for, and graciously received, the help of the USDAs Center for Epidemiology and Animal Health (CEAH) experts who design and analyze national and multidisciplinary animal surveys. The public may be more familiar with their work on the 1998 Equine NationalAnimal Health Monitoring System (NAHMS), which has been widely quoted in lay and scientific literature and has been presented at multiple national and international meetings." More than 200 people worked on this survey, which had the goal of identifying factors associated with MRLS early and late-term abortions in central Kentucky. These included potential risk factors, protective factors which may have 588
helped prevent the syndrome, and those needing fnrther investigation. Results of these studies will be published at www.ca.ukyedu. This is, arguably, the best example of a large cooperative eftbrt of farm owners, managers and their staffs, veterinarians, equine industry representatives, researchers, and state and federal agencies coining together to help solve an equine problem of immense industry and financial significance. (Edited from EquineDisease Quarterly 10(1), 200t.) The House and Senate have passed the Fiscal Year 2002 Agriculture Appropriations Conference Report. This bill will provide $75.9 billion for agriculture programs through the United States Department of Agriculture and other agencies. Included in this bill are two provisions beneficial to horse owners and breeders affected by Mare Reproductive Loss Syndrome (MRLS). The first provision, added to the bill by Senator Mitch McConnell (R-KY), will allow horse breeders who have been affected by MRLS to apply for USDA disaster loans for a period of two years. If approved, The Secretary of Agriculture must provide loans to eligible horse farmers who have suffered a 30% loss in healthy foals in mares owned or boarded by them. "This is great news for Kentucky's horse breeders. They have suffered huge economic losses due to the deaths of numerous foals this year," saidMcConnell. "I applaud my colleagues for recognizing the importance of the horse industry to Kentucky. This measure will allow our horse farmers to get the financial assistance they need to get back on track." As with other emergency loans from USDA, an affected horse breeder must first apply for a loan through his/her local bank. If such aloan is denied, he/she would then be eligible to apply for emergency assistance through the local Farm Service Agency (FSA) office. However, according to a spokesman for the FSA in Kentucky, loans may not actually be available immediately. Since this is his fist time that horse breeders have been eligible for emergency loans, there is no specific application process already in place. Although this program is expected to be administered like other "Emergency Money" programs through USDA, because the horse industry is different than other
crops and livestock, it may take time before USDA can work out the details of the application process and determine how best to distribute the loans. The Farm Loan Program office in Kentucky has been asked to help the USDA write the regulations for this program. Language, which was added by Senator Bunning, was also included to direct the USDA's Animal and Plant Health Inspection Service to help monitor and study MRLS in conjunction with the University of Kentucky. (Edited from AHC News 28(5), 2001.) BOVINE PAPILLOMA VIRUS AND EQUINE SARCOIDS Sarcoids are the most common skin tumors in horses and often result in loss of the animal because of their locations and tendency to recur. Sarcoids develop as a multi-step process, proceeding from a normal cell to a tumor cell. Bovine papilloma virus (BPV), the cause of warts in cattle, appears to be an important factor of tumor formation. Several arguments indicate that the viral infection may be the initiating step towards sarcoid development. Vaccination against the BPV vires does not cause resolution of the tumor. Scientists at the University of California, Davis, believe that the virus is most likely inserting itself into the cell's DNA, causing alterations in the regulation of genes called oncogenes. Oncogenes are growth promoting genes that, if their function is altered, can induce tumor formation. In tissues collected from equine sarcoids, researchers found an increase in the activity of the oncogene, c-myc, and the degree of activity was positively associated with the aggressiveness of the tumors. Researchers hypothesize that, the BPV virus affects normal cells in horses in two ways: it provides the trigger for tumor formation and activates the c-myc oncogene which results in uncontrolled tumor cell growth. Researchers Alain Theon and Elizabith Carr collected tissue and blood samples from 20 horses with sarcoids (10 with multiple tumors and 10 with single tumors) that were referred to the UC Davis Veterinary Medical Teaching Hospital for treatment and also from five control horses. Researchers analyzed the association between the presence of BPV
JOURNAL OF EQUINE VETERINARY SCIENCE
Equine sarcoid. and the increased activity of c-myc. The researchers determined if the increase in c-myc expression was due to gene amplification or due to direct activation of the gene. They then evaluated tissues positive for BPV to determine the location of the viral DNA. They performed statistical analysis to assess if there was any association between the characteristics of viral infection, the changes seen in the oncogene activity, and the clinical characteristics of the different sarcoids. This study shows that the interaction between BPV infection and deregulation of a specific oncogene, c-myc, rather than viral infection alone, plays a crucial role in the development of sarcoids in horses. Further studies are needed to determine which of the two events, BPV infection or c-myc activation, is the determining factor in the development of sarcoids. The lack of c-myc overexpression in normal tissues seems to favor a critical role for the c-myc oncogene. Once researchers gain a better understanding of the molecular basis of cellular transformation leading to sarcoids, then they can develop effective treatment and prevention strategies. Depeuding on whether BPV infection is the leading transforming event or if c-myc activation is required for BPV transforming activity, vaccinating against viral transforming proteins or regulating gene expression (gene therapy) may become effective and economic approaches to the treatment and prevention of sarcoids. (Edited from the UCD's 2001 Research Report.) ROS IN JOINTS Much of the work on horses done at CSU's Orthopaedic Research Center is tied
Volume 21, Number 12, 2001
in very closely to studies involving human orthopedic work. One study, headed by Dr. Paul Siciliano and involving graduate student Abigail Dimock, investigated Reactive Oxygen Species (ROS), also known as Free Radicals, a type of molecule that degrades joint components. ROS have also been found to worsen joint disease in humans. Dr. Siciliano was attempting to discover if this culprit of joint disease in the human athlete is also a contributor to similar problems in the equine athlete. To discover if ROS did contribute to joint problems in horses, Dr S iciliano took samples of synoviat from both normal horses and horses undergoing arthroscopic surgery with Dr. Wayne Mcllwraith. Both Quarter Horses and Thoroughbreds were used in this study. The synovial fluid was tested for the level of protein carbonyl content, which is a marker for damage done from ROS. Dr. Siciliano and Dimock did find that the levels of protein carbonyl content were significantly higher in diseased joints than in healthy joints. This research could open the door to therapy dealing directly with the reactive oxygen species. Free radical scavengers are currently used to reduce the number of ROS in humans. One example of free radical scavengers is Vitamin E.
For effective protection against West Nile fever, the first dose of vaccine must be followed three to six weeks later with a second dose. An annual booster vaccine to maintain protection should be given in the late Spring o1"early Summer. Horses that were vaccinated this Summer and Fall should receive their annual booster vaccine in the late Spring or early Summer of next year, even though it will not be a year since the initial vaccination was given. This will provide these horses with the greatest protection against West Nile infection during the period when vires activity is at it highest. After this, the annual vaccination should occur each spring or early summer. There have been some concerns regarding international restrictions on vaccinated horses, To date, only Columbia and Argentina have restricted the importation of U.S. horses fi'om areas where WNV activity has been identified. The European Union has notplaced restrictions on horses from WNV affected areas and is not expected to. (From AHC News, Sept/Oct, 2001.)
WEST NILE VIRUS
BIO-TERRORISM GUIDE
West Nile fever has occurred in more than 400 horses since the 2001 outbreak began last spring, as it has moved as far south as Southern Horida. WNV has recently been reported in the Cayman Islands. It has moved west with evidence of WNV activity in midwestern states such as Ohio, Wisconsin and Indiana and north into Canada. In July, a conditional license was issued for the use of a vaccine against West Nile fever. The vaccine has proved to be safe with no undue problems being reported from its use. The vaccine is also believed to be effective, provided initial vaccinations include the recommended two doses of vaccine, Protection against West Nile infection does not occur until after the second dose of vaccine is given and, in some cases, illness has occurred in horses exposed to the West Nile virus after the first dose of vaccine had been given.
As professionals in the animal health industry, veterinarians are in a unique position to serve our country by providing an early warning alert in the event of a suspected biological threat. Fort Dodge Animal Health has developed the technical reference: A
Guide for Practicing Veterinarians: Recognizing Suspected Biological Agents Used in Bio-terrorism. This technical reference guide has been distributed to over 50,000 veterinarians nationwide in an effort to help animal health professionals maintain a heightened state of awareness to the potential of biological threats to animal populations. For a copy of the Bio-terrorism Guide, contact the Fort Dodge Animal Health Professional Services Departent at 1-800-533-8536.
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helped prevent the syndrome, and those needing fnrther investigation. Results of these studies will be published at www.ca.ukyedu. This is, arguably, the best example of a large cooperative eftbrt of farm owners, managers and their staffs, veterinarians, equine industry representatives, researchers, and state and federal agencies coining together to help solve an equine problem of immense industry and financial significance. (Edited from EquineDisease Quarterly 10(1), 200t.) The House and Senate have passed the Fiscal Year 2002 Agriculture Appropriations Conference Report. This bill will provide $75.9 billion for agriculture programs through the United States Department of Agriculture and other agencies. Included in this bill are two provisions beneficial to horse owners and breeders affected by Mare Reproductive Loss Syndrome (MRLS). The first provision, added to the bill by Senator Mitch McConnell (R-KY), will allow horse breeders who have been affected by MRLS to apply for USDA disaster loans for a period of two years. If approved, The Secretary of Agriculture must provide loans to eligible horse farmers who have suffered a 30% loss in healthy foals in mares owned or boarded by them. "This is great news for Kentucky's horse breeders. They have suffered huge economic losses due to the deaths of numerous foals this year," saidMcConnell. "I applaud my colleagues for recognizing the importance of the horse industry to Kentucky. This measure will allow our horse farmers to get the financial assistance they need to get back on track." As with other emergency loans from USDA, an affected horse breeder must first apply for a loan through his/her local bank. If such aloan is denied, he/she would then be eligible to apply for emergency assistance through the local Farm Service Agency (FSA) office. However, according to a spokesman for the FSA in Kentucky, loans may not actually be available immediately. Since this is his fist time that horse breeders have been eligible for emergency loans, there is no specific application process already in place. Although this program is expected to be administered like other "Emergency Money" programs through USDA, because the horse industry is different than other
crops and livestock, it may take time before USDA can work out the details of the application process and determine how best to distribute the loans. The Farm Loan Program office in Kentucky has been asked to help the USDA write the regulations for this program. Language, which was added by Senator Bunning, was also included to direct the USDA's Animal and Plant Health Inspection Service to help monitor and study MRLS in conjunction with the University of Kentucky. (Edited from AHC News 28(5), 2001.) BOVINE PAPILLOMA VIRUS AND EQUINE SARCOIDS Sarcoids are the most common skin tumors in horses and often result in loss of the animal because of their locations and tendency to recur. Sarcoids develop as a multi-step process, proceeding from a normal cell to a tumor cell. Bovine papilloma virus (BPV), the cause of warts in cattle, appears to be an important factor of tumor formation. Several arguments indicate that the viral infection may be the initiating step towards sarcoid development. Vaccination against the BPV vires does not cause resolution of the tumor. Scientists at the University of California, Davis, believe that the virus is most likely inserting itself into the cell's DNA, causing alterations in the regulation of genes called oncogenes. Oncogenes are growth promoting genes that, if their function is altered, can induce tumor formation. In tissues collected from equine sarcoids, researchers found an increase in the activity of the oncogene, c-myc, and the degree of activity was positively associated with the aggressiveness of the tumors. Researchers hypothesize that, the BPV virus affects normal cells in horses in two ways: it provides the trigger for tumor formation and activates the c-myc oncogene which results in uncontrolled tumor cell growth. Researchers Alain Theon and Elizabith Carr collected tissue and blood samples from 20 horses with sarcoids (10 with multiple tumors and 10 with single tumors) that were referred to the UC Davis Veterinary Medical Teaching Hospital for treatment and also from five control horses. Researchers analyzed the association between the presence of BPV
JOURNAL OF EQUINE VETERINARY SCIENCE
Equine sarcoid. and the increased activity of c-myc. The researchers determined if the increase in c-myc expression was due to gene amplification or due to direct activation of the gene. They then evaluated tissues positive for BPV to determine the location of the viral DNA. They performed statistical analysis to assess if there was any association between the characteristics of viral infection, the changes seen in the oncogene activity, and the clinical characteristics of the different sarcoids. This study shows that the interaction between BPV infection and deregulation of a specific oncogene, c-myc, rather than viral infection alone, plays a crucial role in the development of sarcoids in horses. Further studies are needed to determine which of the two events, BPV infection or c-myc activation, is the determining factor in the development of sarcoids. The lack of c-myc overexpression in normal tissues seems to favor a critical role for the c-myc oncogene. Once researchers gain a better understanding of the molecular basis of cellular transformation leading to sarcoids, then they can develop effective treatment and prevention strategies. Depeuding on whether BPV infection is the leading transforming event or if c-myc activation is required for BPV transforming activity, vaccinating against viral transforming proteins or regulating gene expression (gene therapy) may become effective and economic approaches to the treatment and prevention of sarcoids. (Edited from the UCD's 2001 Research Report.) ROS IN JOINTS Much of the work on horses done at CSU's Orthopaedic Research Center is tied
Volume 21, Number 12, 2001
in very closely to studies involving human orthopedic work. One study, headed by Dr. Paul Siciliano and involving graduate student Abigail Dimock, investigated Reactive Oxygen Species (ROS), also known as Free Radicals, a type of molecule that degrades joint components. ROS have also been found to worsen joint disease in humans. Dr. Siciliano was attempting to discover if this culprit of joint disease in the human athlete is also a contributor to similar problems in the equine athlete. To discover if ROS did contribute to joint problems in horses, Dr S iciliano took samples of synoviat from both normal horses and horses undergoing arthroscopic surgery with Dr. Wayne Mcllwraith. Both Quarter Horses and Thoroughbreds were used in this study. The synovial fluid was tested for the level of protein carbonyl content, which is a marker for damage done from ROS. Dr. Siciliano and Dimock did find that the levels of protein carbonyl content were significantly higher in diseased joints than in healthy joints. This research could open the door to therapy dealing directly with the reactive oxygen species. Free radical scavengers are currently used to reduce the number of ROS in humans. One example of free radical scavengers is Vitamin E.
For effective protection against West Nile fever, the first dose of vaccine must be followed three to six weeks later with a second dose. An annual booster vaccine to maintain protection should be given in the late Spring o1"early Summer. Horses that were vaccinated this Summer and Fall should receive their annual booster vaccine in the late Spring or early Summer of next year, even though it will not be a year since the initial vaccination was given. This will provide these horses with the greatest protection against West Nile infection during the period when vires activity is at it highest. After this, the annual vaccination should occur each spring or early summer. There have been some concerns regarding international restrictions on vaccinated horses, To date, only Columbia and Argentina have restricted the importation of U.S. horses fi'om areas where WNV activity has been identified. The European Union has notplaced restrictions on horses from WNV affected areas and is not expected to. (From AHC News, Sept/Oct, 2001.)
WEST NILE VIRUS
BIO-TERRORISM GUIDE
West Nile fever has occurred in more than 400 horses since the 2001 outbreak began last spring, as it has moved as far south as Southern Horida. WNV has recently been reported in the Cayman Islands. It has moved west with evidence of WNV activity in midwestern states such as Ohio, Wisconsin and Indiana and north into Canada. In July, a conditional license was issued for the use of a vaccine against West Nile fever. The vaccine has proved to be safe with no undue problems being reported from its use. The vaccine is also believed to be effective, provided initial vaccinations include the recommended two doses of vaccine, Protection against West Nile infection does not occur until after the second dose of vaccine is given and, in some cases, illness has occurred in horses exposed to the West Nile virus after the first dose of vaccine had been given.
As professionals in the animal health industry, veterinarians are in a unique position to serve our country by providing an early warning alert in the event of a suspected biological threat. Fort Dodge Animal Health has developed the technical reference: A
Guide for Practicing Veterinarians: Recognizing Suspected Biological Agents Used in Bio-terrorism. This technical reference guide has been distributed to over 50,000 veterinarians nationwide in an effort to help animal health professionals maintain a heightened state of awareness to the potential of biological threats to animal populations. For a copy of the Bio-terrorism Guide, contact the Fort Dodge Animal Health Professional Services Departent at 1-800-533-8536.
589