Q1 2020 Global Equine Disease Outbreak Report
The following information was provided by the Equine Disease Quarterly of the University of Kentucky and supported by underwriters at Lloyd’s London.
The International Collating Centre, Newmarket, United Kingdom, and other sources reported the following equine disease outbreaks in the first quarter of 2020.
The Republic of South Africa (RSA) confirmed the occurrence of African horse sickness at expected levels within endemic areas of eight of the nine provinces. The highest number of cases were recorded in Gauteng Province; none were confirmed in Western Cape Province.
African horse sickness was also reported for the first time in Thailand. Three outbreaks were confirmed involving 78 cases with 57 fatalities.
An outbreak of Venezuelan equine encephalomyelitis (VEE) was confirmed by Belize. Four of five unvaccinated horses died from the disease.
France, the Netherlands, and the USA recorded outbreaks of equine influenza. The number of outbreaks included four in France (one to 20 cases per outbreak), two in the Netherlands (three to five cases per outbreak), and nine in the USA, where the disease is endemic. The number of cases per outbreak varied from three to 30, with many unvaccinated against the disease.
Strangles is considered endemic in most countries, with reports from Belgium (two outbreaks), France (20 outbreaks), the Netherlands (24 outbreaks), Switzerland (four outbreaks), and the USA (16 outbreaks in 11 states).
Equine herpesvirus type 1 (EHV-1) related diseases were recorded by Belgium, France, Canada, the Netherlands, Switzerland, the UK, and the USA. Respiratory disease outbreaks were confirmed in Belgium (two), France (three), the Netherlands (one), and the USA (six). Abortion due to EHV- 1 was reported by Belgium (four outbreaks, one involving six cases), Canada (one outbreak), the Netherlands (five outbreaks), the UK (four outbreaks), and the USA (eight outbreaks of abortion/neonatal disease, one involving four cases). EHV- 1 neurologic disease was confirmed by Canada (one case), the Netherlands (two outbreaks, one involving two cases and the second, seven cases), Switzerland (single case), the UK (three outbreaks, one involving nine cases), and the USA (seven outbreaks, with two each in California and Virginia).
Numerous countries recorded outbreaks of equine herpesvirus type 4 respiratory disease. These included Argentina (one outbreak in five to seven month old foals), Belgium (one outbreak), France (18 outbreaks, mostly single cases), the Netherlands (two outbreaks), Spain (one case), Switzerland (two outbreaks, one involving co-infection with EHV-1), and the UK (five outbreaks, two linked to new arrivals).
France reported finding the carrier state in three stallions infected with equine arteritis virus.
Equine infectious anemia was confirmed in Canada (a case of subclinical infection) and the USA (three outbreaks, with single cases in California and Texas and three cases in Iowa).
The RSA was the only country to report the presence of equine piroplasmosis. Isolated cases were diagnosed throughout the country.
Two outbreaks of leptospiral abortion were recorded by Belgium, both involving single cases of the disease.
The USA reported a significant number of cases of nocardioform placentitis/abortion. Of 256 cases confirmed, 147 represented cases of placentitis and 109 where the placentitis was accompanied by submission of a fetus or neonate. Amycolatopsis was implicated in 98 cases and Crossiella equi in 65 cases.
A fatal case of Tyzzer’s disease (Clostridium piliforme) infection was confirmed in a foal in Kentucky, USA.
The USA reported a non-fatal case of equine coronavirus infection in a gelding in Arizona.
Rotavirus infection in foals was diagnosed by France (two outbreaks), Spain (one case), and the USA (one case).
The USA reported 10 cases of Lawsonia enteropathy due to Lawsonia intracellularis infection in the first quarter of 2020. It also confirmed detection of Clostridium perfringens in 24 foals originating in Kentucky and Indiana, and Clostridium difficile in 16 foals in Kentucky; these included two toxin Type A strains and two toxin Type B strains.
The RSA recorded cases of equine encephalosis in seven of the country’s nine provinces, with over 100 cases diagnosed in Gauteng Province.