International Equine Disease Report, Fourth Quarter 2008

The International Collating Centre, Newmarket, England, and other sources reported the following disease outbreaks:

Two cases of contagious equine metritis (CEM) were confirmed in non-Thoroughbred horses in France. As of Feb. 23 the USDA reported 11 non-Thoroughbred stallions positive for (CEM) during the recent outbreak--four in Kentucky, three in Indiana, three in Wisconsin, and one in Texas. Three non-Thoroughbred mares have been identified as CEM positive in Wisconsin, Illinois, and California following natural breeding or via semen from stallions recently identified as CEM positive.

During 2008 the USDA reported 168 cases of Eastern equine encephalitis throughout the United States, with 86 cases in Florida, 22 in Georgia, and 21 in Alabama.

Respiratory disease attributable to equine herpesvirus (EHV) was diagnosed in a horse in France. Neurological disease attributable to EHV-1 was diagnosed in a horse in France and three polo ponies in the United Kingdom. Clinical signs exhibited by the polo ponies were not typical of EHV despite evidence of seroconversion and isolation of EHV-1 from the nasopharynx of one animal. Sporadic cases of EHV-associated neurological disease were reported from several parts of the United States. A case in a 7-year-old pony in Kentucky during November was caused by the non-neuropathogenic strain. During December two horses were euthanized on separate farms in Delaware resulting from the non-neuropathogenic strain, and a 2-year-old Thoroughbred filly at Laurel Park racetrack, Maryland, was euthanized following EHV-1 infection. At the end of December a Thoroughbred horse at Fair Grounds racetrack, Louisiana, developed signs of paralysis caused by EHV-1. Japan and the United Kingdom each reported a single case of EHV-1 abortion, and three cases were reported in central Kentucky.

A single case of equine infectious anemia (EIA) was confirmed in South Germany. Switzerland reported the results of a serological survey undertaken during 2007 and 2008 among 666 domestic and imported horses, all of which tested negative for EIA.

Equine arteritis virus infection with clinical signs was diagnosed among non-Thoroughbred horses on three premises in Denmark.

Twelve months following the last confirmed case of equine influenza in Australia on December 27, 2007, the World Organization for Animal Health (OIE) formally acknowledged the country's status as free of equine influenza. Sweden reported that performance and breeding Thoroughbreds as well as non-Thoroughbreds were diagnosed with equine influenza on approximately 50 premises. Six trotting tracks were temporarily placed in isolation, but as of January 8, only one track remained isolated.

Two cases of equine piroplasmosis affecting non-Thoroughbred horses on two premises were reported from Switzerland.

Salmonella abortus equi infection affecting three non-Thoroughbred horses was diagnosed on one premise in Japan. Cases of strangles were confirmed from France, Ireland, Switzerland, and the United Kingdom.

West Nile virus (WNV) infection was reported affecting 474 horses on 235 premises in central-east Italy during the last six months of 2008. Performance horses, breeding animals, and non-Thoroughbreds were involved. The USDA reported 162 cases of WNV infection among horses in the United States during 2008, with 32 in California and 41 in the state of Washington. This compares with 1,370 human cases with 37 fatalities reported by the centers for disease control throughout the United States over the same period, with 411 cases in California and 99 in Mississippi.

South Korea reported the results of a serological survey conducted among 1,085 Thoroughbred horses including stallions, broodmares, young horses, and racehorses during 2008. All samples were negative for African horse sickness, EIA, vesicular stomatitis, and WNV. Ninety-five percent of samples were positive for Japanese encephalitis as a result of vaccination, infection, or both.

This is an excerpt from Equine Disease Quarterly, funded by underwriters at Lloyd's, London, brokers, and their Kentucky agents.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.