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Livestock Disease Diagnostic Center Emerging Diseases and Disease Management Update 2007 ANR Update Patty Scharko, DVM, MPH, DACVPM Extension Ruminant Veterinarian. EHD Epizootic Hemorrhagic Disease of White Tail Deer. http://fw.ky.gov/gifs/ehdcounties.gif. EHD Details.
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Livestock Disease Diagnostic Center • Emerging Diseases and Disease Management Update • 2007 ANR Update • Patty Scharko, DVM, MPH, DACVPM • Extension Ruminant Veterinarian
EHD Epizootic Hemorrhagic Disease of White Tail Deer http://fw.ky.gov/gifs/ehdcounties.gif
EHD Details EHD does not affect humans, nor impact the safety of consumed deer EHD is caused by the bite of an infected midge and once there has been a hard freeze, the insects die off for the winter, eliminating new cases of EHD Most significant disease of white-tailed deer in the United States Virus identified and described in 1955 in NJ Enzootic to Southeastern United States Outbreaks often associated with drought Can result in high deer mortality in some areas
EHD Symptoms in Deer Symptoms vary depending on virulence of the virus and resistance of the deer Animals may appear feverish Have pronounced swelling of head, neck, tongue, and eyelids May have respiratory distress Internal hemorrhaging Highly virulent strains may cause death in 1-3 days Carcasses often recovered near water
EHD Transmission in Deer The EHD virus does not appear to be transmissible to humans The virus deteriorates in <24 hours after death and cannot be spread from dead deer carcasses “The virus does not appear to be a threat to livestock” There appears to be no risk associated with direct exposure to the virus or in consuming a deer that has been infected with the virus However, never kill or eat a sick deer Use rubber gloves to field dress deer
First signs 7 to 8 days after infection • Fever (106-107) • In 24 hrs, salivation & frothing • Lesions in mouth http://ec.europa.eu/food/committees/regulatory/scfcah/animal_health/bluetongue_scofcah_belgium.pdf
Reluctance to move http://ec.europa.eu/food/committees/regulatory/scfcah/animal_health/bluetongue_scofcah_belgium.pdf
Epizootic Hemorrhagic Disease Prior exposure to a related Orbivirus can produce clinical cases in cattle. EHD reported in at least 14 counties in 2003.
USDA/APHIS/VS Foreign Animal Disease Investigation • Differential diagnoses include: • Plant photosensitization • Foot-and-mouth disease • Vesicular stomatitis • Bovine virus diarrhea • Malignant catarrhal fever • Infectious bovine rhinotracheitis • Parainfluenza-3 • Contagious ecthyma (orf/soremouth) • Actinobacillosis
Future Complications In some instances severe breaks in the hooves occur 40 to 60 days after infection and are usually followed by foot rot
Future Complications1 Severe breaks in the hooves may occur 40 to 60 days after infection and are usually followed by foot rot Bulls may become temporarily sterile following acute infections Congenital defects Most susceptible period for fetal infections occurs between 60 - 140 days gestation “Dummy” calves Fetal death 1 Reported on Bluetongue cattle cases
Prepared by Jackie Smith, LDDC Epidemiology Research Analyst
Prepared by Jackie Smith, LDDC Epidemiology Research Analyst November 2006
Flies, Deer, Sheep BVD Acute Infection Subclinical Acute death Fever Diarrhea Transient Infection Infertility Bleeding disorders Immunosuppression Respiratory disease Persistent testicular infections Fetal Infection Transient in utero infection Abortion Birth defects Congenital infection Persistent Infection Acute death Poor performance Normal appearance Mucosal disease Immunosuppression
Vaccinate cows & heifers prior to breeding Bull BSE’s Breeding Season Calving Season March: castrate, dehorn, and vaccinate calves May: wean calves & pregnancy test cows Intense Biosecurity July: strategic summer deworming Fall Calving Herd January October April July Slides courtesy of M. Daniel Givens, DVM, PhD, Auburn University
Vaccinate cows & heifers prior to breeding Bull BSE’s Calving Season May: castrate, dehorn, and blackleg vaccinate calves June/July: strategic summer deworming September/October: wean calves & pregnancy test cows Intense Biosecurity Late fall: lice control Spring Calving Herd May Breeding Season August February November
Calf-Heifer Vaccination Program Proper timing +/- Possible timing- Determine with your veterinarian what is best for your farm. ? Questionable vaccine effectiveness
Cow-Bull Vaccination Program Proper timing +/- Possible timing- Determine with your veterinarian what is best for your farm. ? Questionable vaccine effectiveness
Classes of DewormersGoats/ Sheep Imidazole/ Pyrimidine Macrolide Benzimidazole Drug Class Ivomec Dectomax Eprinex Cydectin** Safeguard/ Panacur Synathic/ Benzelmin Valbazen* Levasole/ Tramisol Rumatel StrongidT Trade Names *Do not use in first trimester pregnancy ** Use sparingly to maintain efficacy
Anaplasmosis • Definition • Infectious, transmissible rickettsial disease of ruminants characterized by progressive anemia • Cause • Anaplasma marginale • Economic losses • Cattle deaths • Trade barrier issues with Canada
Anaplasmosis • Source of Infection • Cattle • Wild ruminants- ?white tail deer • Transmission • Ticks, biting insects- horsefly, horn flies? • Blood contaminated instruments- dehorning, castration, contaminated needles, implant needles • Pathogenesis- occurs when 1% of red blood cells are infected • Destruction of RBC’s by spleen
Anaplasmosis • Clinical Signs Incubation period of 4-6 weeks Dependent upon age • Often fatal in cattle greater than two years • Fever, lethargy, constipation, dry muzzle • Mucus membranes: pale yellow • Staggering, collapse, sudden death • Survivors are carriers
Anaplasomsis • Persists in vectors (ticks) & inapparent carriers • Control and Prevention • Treat herd- long acting oxytetracycline • Insect control: • ear tags • insecticidal sprays/dips
Anaplasomsis • Control and Prevention • Injectable oxytetracycline • OIE recommends 10 mg/lb daily for 5 days (may not be effective with Iowa St. Univ. research) • Two doses at 13.6 mg/lb 5 days apart did NOT work (ISU) to eliminate carrier status • Two doses 9mg/lb 7 days apart (Canadian restricted feeder cattle program) NOT successful • Oral consumption of chlortetracycline for 120CONTINUOUS days at 0.5 mg/lb body weight
Current Label Claims "Beef Cattle (over 700 lb): Control of active infection of anaplasmosis caused by Anaplasma marginale susceptible to chlortetracycline. - 0.5 mg/lb Chlortetracycline body wt/day. Beef and Non-Lactating Dairy Cattle (over 700 lb): Control of active infection of anaplasmosis caused by Anaplasma marginale susceptible to chlortetracycline when delivered in a free-choice feed. Free-choice feed must be manufactured under a feed mill license utilizing an FDA approved formulation. - 0.5 to 2.0 mg/lb Chlortetracycline body wt/day."
Anaplasomsis • Control and Prevention • Test for carriers with C-ELISA test on blood 4 to 6 months after treatment/ exposure • Vaccination • No commercially approved vaccine available • Experimental “Anaplasmosis Vaccine” in LA available with State Veterinarian’s permission