Cornell Researcher Compares EHV Vaccines

ITHACA, N.Y. -- Following a 2005 deadly outbreak of equine herpes virus at Churchill Downs in Kentucky, a Cornell University virologist says his preliminary research indicates that vaccines containing weakened live viruses, called modified live vaccines (MLV), appear to be more effective in preventing horse herpes than other more widely used vaccines.

"It's important that people know that the MLV has been in use for decades, has proven to be reasonably safe, and--in my opinion--it should be the vaccine of choice, at least in non-pregnant animals," said Klaus Osterrieder, associate professor of virology in the College of Veterinary Medicine at Cornell.

Osterrieder's preliminary study compared the effectiveness of MLV vaccines to another more widely used vaccine for equine herpes. Owners and veterinarians have been wary of live vaccines because of past incidences in which a previous MLV that was incompletely weakened caused neurological disease symptoms after it was administered. The more widely used type of vaccine, called an inactivated vaccine, employs a killed virus to activate the horse's immune response.

Osterrieder vaccinated five horses with an MLV and five with an inactivated virus; five received no vaccination. None of the 15 horses was pregnant. The horses were then exposed to the herpes virus.

The study found that the horses with MLV vaccinations consistently had lower fevers, no neurological disorders and less virus in nasal fluids. One horse vaccinated with the inactivated virus and one from the control group showed mild neurological symptoms. All the horses, however, have fully recovered.

Read the full story at www.vet.cornell.edu/news/articles/horseHerpes.htm.

To clone or not to clone, that is (legal and ethical) question in UK

"Clone!" would be the resounding response if you asked Professor William "Twink" Allen of the Equine Fertility Unit of the Thoroughbred Breeders Association in Newmarket, England. Professor Allen developed the procedure and technology used in equine cloning experiments around the world, including mules and horses "born" in the U.S., Italy and Australia.

But it's not that simple, at least not in the United Kingdom. When Professor Allen applied for a license to clone equine embryos in 2001, his request was rejected and his projects were curtailed in spite of his world leadership role in the process. Allen refused to take "no" for an answer and battled on in a legal process that resulted in an overturn of the UK ban on March 30 of this year.

Professor Allen's celebration was short-lived, however, as the government tempered his approval with the caveat that his cloning be limited to research purposes only. Cloning of horses for any commercial purpose remains illegal in England.

"It is absurd!" Allen told EQUUS magazine in April. "This is a perverse ruling, in the extreme. Our goal is not the exploitation of horses."

Chief among Allen's goals is cloning the DNA of champion geldings. Looking back to a typical Badminton Three-Day Event, he cited 118 entries, comprised of 114 geldings and 4 mares. Each of the mares was over 14 years old. "You're talking about a championship event between a bunch of eunuchs and four grandmothers.

"We are not out to reproduce winning geldings directly, but to make their championship DNA available," he stressed.

Research projects at Allen's lab that are approved by the British government include equine mitochondrial DNA research and the function of paternal antigens, which affect the mare's immune system and allow pregnancy to take place without spontaneous abortion. "Mares would normally reject the foreign substance, but how and why the paternal antigens function will be valuable research," Allen stated.

Allen lays part of the blame for his one-hand-tied researcher status at the feet of the government's compliance with animal –rights activists who oppose cloning research. UK-based Animal Aid has awarded Professor Allen the dubious distinction of being one of its "Mad Scientist" award winners. Allen was singled out, along with researchers at the Animal Health Trust, Cambridge University, the Royal Veterinary College, Intervet UK and University of Edinburgh for conducting research perceived as injurious to horses.

"They're afraid we'll make a mistake and create an abnormal animal," Allen said, referring to the government's conditional lift of the ban on his projects. "In France, they have the DNA of 30 champion competition geldings on ice, but they don't have the science. We have it, but we're not allowed to do it."

Weight Loss During Transport Documented in New Study

Did you know...that a horse can use as much energy during a 10-mile trailer ride as on a 10-mile trail ride? It's true, according to equine nutritionist Teresa Hollands PhD of DeMontfort University in Leicestershire, England. Fluid loss is a major factor, as it is in humans. One horse, tape-weighed by Hollands before leaving for an event, lost 20 kg (more than 40 pounds) during the three-hour ride to the competition. British three-day event horses in a research study also lost an average of 14.5kg (34 pounds) on cross-country day.