UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail: dfculbert@ifas.ufl.edu

August 26, 2003

Feature Article - for release September 1, 2003

Dan Culbert - Extension Horticulture Agent

Excuse the pun, but our office has just received some "bits" of information that local horse owners ought to know about. First the bad news - there are some reports in Florida of horse feed that has been contaminated with blister beetles. This feed has effected eight horses in Dade County, with three of these animals having died from eating this alfalfa hay from Oklahoma.

Second is the good news - since the West Nile virus has now been reported as infecting a local horse. The recent approval of a horse vaccine that can protect these animals from this disease is timely. Information for today’s column comes from the University of Florida, the Florida Departments of Agriculture and Health, and the USDA.

This summer there have been three outbreaks of "blister beetles" contaminated alfalfa hay. The Florida Department of Agriculture has determined that the hay has come from Oklahoma. In the latest incident, eight horses in Miami-Dade County have been afflicted by contaminated feed, with three horse deaths being reported. Earlier outbreaks were reported this summer in both Clay and Palm Beach counties.

Florida’s Secretary of Agriculture Charles Bronson is urging horse owners who use imported alfalfa - especially from Oklahoma - to deal only with reputable suppliers and to examine their feed carefully before providing it to their horses. Anyone with questions or concerns about their feed supply are advised to contact their feed dealer or veterinarian.

Blister Beetle residues are occasionally found in alfalfa hay imported into Florida as a result of modern haying practices, which crush the beetles during hay baling. The beetle releases a highly irritating substance into the hay, resulting in severe colic and sometimes death of horses which consume the contaminated hay.

For more about the blister beetle and its effects, request the University of Florida Featured Creatures bulletin from this office or click here to go to the publication .  Horse owners may also contact the FDACS Division of Animal Industry at (850) 410-0900 with any questions about "blister beetle" poisoning.

Horse Vaccine for West Nile 

The USDA just announced that it has issued a conditional license to Novartis Animal Vaccines Inc. for a horse vaccine product to aid in the treatment of horses with the West Nile virus. Click here to go to the press release.

West Nile is a mosquito-borne virus that was first detected in the United States in 1999. The virus can cause inflammation of the brain (encephalitis) in animals and, in some cases, humans. It has recently has spread to many regions of the United States, including Florida.

If horses are infected with West Nile virus, they can show effects in their nervous system. There is no documentation that infected horses can spread the virus to uninfected horses or other animals. In 2002, there were 14,717 cases reported in the US of horses infected with the virus.

The most common signs of West Nile virus infection in U.S. horses have been stumbling or lack of coordination, weakness of limbs, partial paralysis, muscle twitching and death. Fever has been detected in less than one-quarter of all confirmed cases. About one-third of horses that become ill with West Nile virus die or must be euthanized.

USDA’s Animal and Plant Health Inspection Service (APHIS) issues conditional licenses for veterinary products to meet special circumstances such as this outbreak of the West Nile virus. Under these regulations, the Novartis product has shown to be pure and safe and demonstrates a reasonable expectation of efficacy.

In keeping with these regulations, the product described above has been issued a conditional license for one year. The product is given by a veterinarian where use of the product has been approved by state authorities.

As of August 18, the State Department of Health has confirmed one case of equine infection in our county due to West Nile virus, but no cases of human infection have been reported. Other nearby cases of West Nile reported so far this year have been human cases in Brevard, Broward and Lee counties, and sentinel chickens in Indian River, St. Lucie and Martin Counties. For the latest information, go to the UF Mosquito Information page.

Equine Institute galloping to Ocala

For serious equine owners, the 2003 Florida Equine Institute and Allied Trade Show is scheduled for Thursday September 25 in Ocala. This one day program will offer the latest information on horse breeding featuring experts from both Florida and Kentucky. Contact our office if you want a copy of the program brochure. For more information on the Equine Institute, contact Sharon Gamble at (904) 822-5778 or Mark Shuffit at (352) 620-3445.

If you need additional information on these horse health situations, call or stop by our office at 458 Hwy 98 North. Our phone number is 763-6469, and you can email us at okeechobee@ifas.ufl.edu.

Other Links and references:

Collins, Caroline and Blackmore, Carina. "Arboviral Activity Summary Through the Week Ending August 25, 2003" .Florida Department of Health: August 25, 2003.

Holl, Suzan and Redding, Jerry. "USDA Issues Conditional License for West Nile Virus Treatment for Horses" (Press Release). Washington: USDA APHIS August 19, 2003.

Jeter, Bill. "Contaminated Feed Detected in Miami-Dade; Third Such Incident in Florida this Summer, Bronson Reports". (Press Release) Tallahassee: FDACS August 20, 2003.

Lord, Cynthia C. And Rutledge, Roxanne. Protecting Florida Horses From Mosquitoes. Bulletin ENY 646. Gainesville, UF/IFAS Cooperative Extension Service, July 2001. ENY 646.

McElroy, Terence. "Contaminated Feed Detected in Palm Beach County, Bronson Reports" (Press Release) Tallahassee: FDACS August 8, 2003.

Novartis Animal Vaccines, Inc. West Nile Virus Antibody: Take Control of the West Nile Virus.

Rutledge, Roxanne. West Nile Virus: Risk and Prevention for Horses in Florida  Bulletin ENY 651. Gainesville, UF/IFAS Cooperative Extension Service, July 2001.

Rutledge. Roxanne. Mosquito Information page. [Updated information on West Nile Activity]. Vero Beach: UF/IFAS Florida Medical Entomology Laboratory: August 18, 2003.  .

Selander, Richard B. and Fasulo, Tomas J. Blister Beetles (Feature Creatures Series) EENY-166 Gainesville: UF/IFAS Cooperative Extension Service, August 2003.