The International Collating Center, Newmarket, United Kingdom, and other sources reported the following disease outbreaks in the first quarter of 2011.

Contagious equine metritis was reported from France (one case) and Germany (four cases).

Reports of equine influenza were received from France and Sweden. Eight premises were affected in France (seven of which were epidemiologically linked). The virus involved was a H3N8 strain of the Florida clade 2 sublineage. Isolated cases of the disease were confirmed in Sweden.

Extensive outbreaks of African horse sickness occurred in the northern and eastern parts of South Africa, where the disease is endemic, primarily in young, unvaccinated horses. Cases were also reported in the surveillance zone of the Western Cape.

Strangles was reported from France (six premises), Germany (four cases), South Africa, Sweden, Switzerland (two cases), the U.K. (endemic), and the United States (six cases in Kentucky).

Reports of equine infectious anemia were received from Germany (five outbreaks) and Japan (one case).

In northeastern Argentina, five mares on one premise died from rabies; exposure to infected vampire bats was presumed.

In the United States, two cases of Eastern equine encephalomyelitis were diagnosed in Louisiana; both were fatal.

Outbreaks of equine herpesvirus-1 (EHV-1) related disease (respiratory, abortion, and/or myeloencephalopathy) were reported by numerous countries. France reported isolated cases of EHV-1 respiratory disease on three premises; Germany reported one case.

EHV-1 respiratory disease with myeloencephalopathy was confirmed on four additional premises in France; three were epidemiologically linked. Of 100 resident horses on one premises, 68 developed fevers, and 16 also exhibited signs of neurologic disease; one had to be euthanized. The remaining three affected premises had one, two, and seven cases, respectively.

Abortions caused by EHV-1 were confirmed in Argentina (one case) and France (single cases on four premises and two cases on each of three premises).

France also reported EHV-1 neurologic disease and abortion involving five Trotters on an additional premises. Abortion was also recorded in Germany (10 cases), Japan (11 cases involving eight premises), Turkey (15 cases on two premises), the U.K. (three cases and an additional two cases of abortion on another premises following signs of neurologic disease; a final case diagnosed in a neonatal foal), the United States (four cases in Thoroughbreds and a case of fulminant pneumonia in a neonatal foal).

Outbreaks of EHV-1 myeloencephalopathy not associated with respiratory disease or abortion were reported from France (four premises), Germany (one case), the U.K. (isolated cases), and the United States (two premises).

Outbreaks of equine herpesvirus-4 respiratory disease were confirmed in Germany (five cases), Sweden (six cases), and the U.K. (one abortion).

Other equine herpesvirus outbreaks recorded were one case of multinodular pulmonary disease in a donkey in Switzerland attributed to EHV-5 and one case of equine coital exanthema (a venereal disease in horses caused by EHV-3) in a zebra in the U.K..

Equine piroplasmosis (EP) was reported to be endemic in France, South Africa, Spain, and the United Arab Emirates. Korea had one subclinical case.

Cases primarily of Babesia equi infection continue to be diagnosed in the United States, the majority in racing Quarter Horses. Of over 100,000 horses tested to date, 74 have been found seropositive in a total of 18 states. A significant percentage of the positive horses had been imported from EP-endemic countries. Evidence would indicate transmission occurred by iatrogenic (inadvertent complications resulting from medical treatment) means in most cases. Eleven states now require EP testing of horses competing in sanctioned races/other equine events.

Lawsonia intracellularis infection was reported in the United States. The prevalence of infection, although very high on particular premises, was infrequently associated with an increased incidence of disease. The first quarter of 2011 saw an increase in the incidence of nocardioform placentitis and abortion in Kentucky, United States, with the greatest number of cases diagnosed in January and February.

Equine encephalosis was reported to be endemic in South Africa, where extensive outbreaks occur annually in the summer months.

Outbreaks of clostridial enterocolitis were recorded in the United States, the vast majority attributed to Clostridium perfringens. Switzerland confirmed a case of botulism.

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

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Equine Disease Quarterly

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