A study conducted by CSU veterinarians revealed that no horses that were infected by the West Nile Virus, which were fully vaccinated, died.
But because of the small number of horses that were fully vaccinated, scrutiny of the vaccine’s efficacy still remains.
“Because the overwhelming majority were not fully vaccinated we are not ready to say that the vaccine fully protects horses,” said Josie Traub-Dargatz, equine professor and co-investigator of the study.
Out of the more than 500 horses studied, only 13 were fully vaccinated.
“In order to be fully vaccinated the horse must have received two doses in a three-to-six week interval and have been vaccinated at least three weeks before the horse was infected with the virus,” said Tricia Salazar, CSU equine veterinarian and supervisor of the study. “This time allows for the body to build up resistance to the virus.”
The vaccination called West Nile -Innovator(tm) was fully licensed by the U.S. Department of Agriculture on Feb. 6.
The study’s results will now give equine owners more information when deciding how to prevent their animals from obtaining the virus.
“By interviewing these owners we know how to better educate the public,” Traub-Dargatz said. “The results of the study suggest that vaccination is helpful in preventing the disease.”
Many owners worry about possible side effects that may arise from the vaccination.
“I heard at one time that if the horse only has been vaccinated partially it is more likely to die if it is infected,” said Deborah Otto, a horse owner who opted to vaccinate despite the rumors of possible risk. “I went with my veterinarian’s opinion.”
The study suggests that the talk of such a risk may now be put to rest.
Even if the horse is only partially vaccinated they have a substantially higher rate of survival, Salazar said.
The study showed that 36.6 percent of the animals died with no vaccination compared to 20.3 percent of the animals that had been at least partially vaccinated.
But the biggest reason why owners opt to not vaccinate is not because of side-effects to the horse, but instead to the wallet.
“The average cost of vaccination is between $40 and$50,” Traub-Dargatz said. “But the financial impact of a horse who has been infected with the disease could very well be ten times that of vaccination cost.”
The study, which was conducted by CSU College of Veterinary Medicine and Biomedical Sciences honors students, was more than just obtaining statistics.
Stories of sadness and gloom were frequently heard by owners with horses that did not survive the virus, according to the students who conducted the surveys.
“The clinical aspect of what we were doing was so important,” said Nicki Seehafer, sophomore veterinary medicine and biomedical science major. “We’re talking about literally thousands of horses dying.”
“This is really cutting-edge information,” said Traub-Dargatz.
Other significant information obtained from the story is outlined below.
* Male horses were infected more frequently than females among those cases studied. The results reported that 53.8 percent were males and 46.2 percent were females.
* An altered gait was the prevailing symptom of newly-infected horses, including stumbling and weakness.
* Donkeys and mules can develop the virus
* Of the animals that survived the virus, 82 percent were considered fully recovered by their owners.