Delaware Department of Agriculture News Release May 21, 2014
West Nile Virus and Eastern Equine Encephalomyelitis both spread by mosquitoes
With warm weather here and mosquito season under way, Delaware horse owners are being advised to make certain their equines’ vaccinations are current to protect against the threat of two potentially fatal diseases.
Unvaccinated horses suffer most severely from both West Nile Virus and Eastern Equine Encephalomyelitis, which are spread by infected mosquitoes and can be fatal, said Delaware State Veterinarian Dr. Heather Hirst, who heads the Delaware Department of Agriculture’s Poultry and Animal Health Section. Delaware had two confirmed equine cases of EEE and six confirmed equine cases of WNV in 2013.
“Vaccination is a simple and cost-effective way of preventing these diseases – far cheaper than treating them,” Hirst said. “Horse owners should take full precautions to keep their horses safe, and be on the alert for signs of infection.”
Both horses and humans can contract WNV and EEE if bitten by a mosquito carrying the virus, but it is important to note that the viruses cannot be transmitted between horses or from horses to people. The viruses normally exist in a cycle between mosquitoes and birds, but occasionally EEE can be transmitted from mosquitoes to mammals.
The Mosquito Control Section of the Delaware Department of Natural Resources and Environmental Control monitors for both diseases statewide. DNREC began spraying for mosquitoes in mid-March, treating wooded wetlands near populated areas in all three counties.
Hirst said horse owners should contact their veterinarian immediately if they suspect their horse may be showing signs of WNV or EEE, which both may include fever (though not always with WNV), anorexia, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle spasms in the head and neck, or hind-limb weakness.
Owners should consult with their veterinarians about the WNV and EEE vaccinations, as well as vaccinations for herpesvirus (rhinopneumonitis), influenza, rabies and tetanus, among others, Hirst said.
Horse owners can also help during mosquito season by keeping horses inside during dawn and dusk, which are peak mosquito times, and using topical insect repellents labeled for use on horses, Hirst said.
Beginning in June, DNREC’s Mosquito Control Section will be asking the public’s help in monitoring for the presence of WNV by reporting sick or dead wild birds of certain species that may have contracted the virus. Sick or dead crows, blue jays, cardinals, robins, hawks or owls, and clusters of five or more sick or dead wild birds of any species, should be reported to Mosquito Control’s two offices: Glasgow, for northern Kent County and New Castle County, (302) 836-2555; or Milford, for southern Kent County and Sussex County, (302) 422-1512. Bird specimens should have been dead for less than 24 hours and not appear to have died or been killed by other obvious causes.
For more information about WNV or EEE:
- Human health questions should be directed to the Delaware Division of Public Health, (888) 295-5156, or (302) 744-1033.
- Animal health questions should be directed to the Delaware Department of Agriculture at (800) 282-8685 (Delaware only) or (302) 698-4500. Ask for the Poultry and Animal Health Section.
- Questions about the state’s mosquito control program or mosquito biology should be directed to the Delaware Department of Natural Resources and Environmental Control’s Mosquito Control Section at (302) 739-9917.
- Visit the previous University of Delaware Equine Extension blog post on West Nile virus http://extension.udel.edu/equine/2013/08/23/protect-your-horses-from-west-nile-virus/
Please report neurological horses to the Delaware Department of Agriculture’s Office of Poultry and Animal Health so animal health officials can be included in following up with test results, if diagnostic tests are ordered. Because there is no public health veterinarian in Delaware, Deputy State Veterinarian, Dr. Regina Jensen, is the point of contact with Delaware Division of Public Health and eventual required reporting to Centers for Disease Control and Prevention in regards to arbovirus suspects and positives. If a horse owner or veterinarian is calling with a neurological horse, please request Dr. Heather Hirst or Dr. Regina Jensen.