Equine Disease Outbreaks 2009
Posted: December 7, 2009
Contagious equine metritis (CEM) was recorded in France, the United States, and the United Kingdom (UK). One case of Taylorella equigenitalis infection was confirmed in France. The number of CEM-carrier animals detected in the USA since the disease was initially confirmed mid-December 2008 remains at 20 stallions, one gelding, and five mares. With one exception, all carrier stallions have been non-Thoroughbreds located at facilities specializing in semen collection for artificial insemination. No evidence exists of spread of CEM to the Thoroughbred population. The isolation of T. equigenitalis from a non-Thoroughbred performance horse stallion was reported from the UK. The stallion was a European import and had not been bred after entry to the UK.
Isolated cases of abortion attributable to EHV-1 were confirmed on one premises in France, four premises in Ireland, and two premises in Japan. The UK reported 14 cases of abortion attributable to EHV-1. Single cases of EHV-1 neurologic disease were diagnosed on two premises in Ireland, and multiple cases of EHV-1 were reported on a third premises. Sporadic cases were reported on three premises in the UK. Equine herpesvirus-4 was responsible for three cases of abortion and two cases of respiratory disease in Ireland and one case of respiratory disease in the UK. Mild outbreaks of equine influenza were confirmed on two premises in the UK. Spain reported five cases of influenza in Thoroughbreds, and Sweden recorded the disease on two premises. Influenza was diagnosed on eight premises in France involving multiple breeds; all were epidemiologically linked. The virus was closely related to the Ohio 2003 strain of H3N8 virus.
Twenty-one cases of strangles in 10 separate outbreaks were recorded in Ireland; Sweden reported the disease on 28 premises, and it was confirmed in at least 30 horses on three premises in South Africa. Isolated cases occurred on six premises in France. The annual recurrence of African horse sickness in South African horses involved primarily mild disease in young, unvaccinated animals. Equine infectious anemia was identified in 16 horses on three premises in southeastern France.
Outbreaks of piroplasmosis due to Babesia caballi and/or Theileria parva were reported from France, Switzerland (five cases on five premises), Turkey (two cases on two premises), the United Arab Emirates (limited outbreaks), South Africa (multiple cases, one outbreak), and the USA (seven cases on one premises).
Thirteen cases of abortion meeting the diagnostic criteria for mare reproductive loss syndrome (MRLS) were reported from Kentucky between May 5 and June 15: seven late-term abortions and six early fetal losses. Multiple breeds were affected; several affected farms reported significant numbers of Eastern tent caterpillars concurrently with MRLS. Recurrence of vesicular stomatitis (New Jersey serotype) was reported from the United States in June. Isolated cases of the disease were confirmed in equines on one premises in New Mexico and three in Texas. The United States also reported cases of Eastern equine encephalomyelitis in Florida, Georgia, and Louisiana.
Reference: Equine Disease Quarterly