WNV and equines slides

Myths and Facts on Administration of WNV vaccines to pregnant mares : Myths and Facts on Administration of WNV vaccines to pregnant mares Linea Richards and Stephanie K Schoepfer-Grosskurth


Internet Rumors on WNV vaccinating of pregnant mares. : Internet Rumors on WNV vaccinating of pregnant mares. http://www.rense.com/ Stillborn, aborted, and deformed foals may be linked to West Nile Virus vaccine. Reports are coming from across the nation of troubled births, including a foal born with no front legs. http://lost-foals-group.4t.com/index.html contains testimonials by breeders claiming WNV vaccines caused abortions in their broodmares.


My Andalusian Mare foaled in March, the filly was born without front legs. She has had 5 previous births(she is 9 years old) She recieved the Vaccine at the end of her first 30 days of pregnancy, then two weeks later. Fort Dodge is now ignoring my calls and emails. My foal was sold and the price was 20,000.Toni CAPhoto shown below provided by owner. : My Andalusian Mare foaled in March, the filly was born without front legs. She has had 5 previous births(she is 9 years old) She recieved the Vaccine at the end of her first 30 days of pregnancy, then two weeks later. Fort Dodge is now ignoring my calls and emails. My foal was sold and the price was 20,000. Toni CA Photo shown below provided by owner.


Javma Study : Javma Study Evaluation of administration of West Nile virus vaccine to pregnant broodmares By Vest et. al


Materials and Methods : Materials and Methods 4 farms used 2 Quarter horse 2 Thoroughbred 595 mares total Each mare had received a primary and booster vaccination against WNV in 2002


Time Periods : Time Periods Pregnancy losses and time of vaccine administration were categorized based on the time during the pregnancy that they had occurred Early embryonic (ovulation – 40 days) Early Fetal (41-150 days) Late Fetal (>150 days)


Results : Results 31 mares had early embryonic deaths 20 had early fetal loss 25 had late fetal loss No significant correlation between time of vaccination and abortion. Each farm had a different proportion of mares vaccinated during each period of pregnancy.


Discussion : Discussion Killed WNV did not adversely affect pregnancy outcome. Administration of vaccine during any of the 3 periods of pregnancy did not increase pregnancy loss during that period or subsequent ones. Overall pregnancy loss was within the reported range of typical losses.


Problems with study : Problems with study Exact time of abortion not known (mares were not checked everyday). Small cohort size No control group


Conclusions : Conclusions Safe to vaccinate pregnant mares for WNV during mosquito season. Might promote passive immunity for the foal if vaccinated in the last 3 months of pregnancy.


WNV in Equine Magazines : WNV in Equine Magazines Horse Illustrated – Vaccination task force of AAEP recommends vaccinating before breeding since vaccines are not labeled for administration to pregnant mares. The Horse – Reports on JAVMA study. Researchers for the study are quoted as saying “This study should alleviate some of the horse owners’ fears that there are any adverse reproductive side effects to the WNV vaccine.”