The following report was provided by the Equine Disease Quarterly—funded by underwriters at Lloyd’s, London. The Equine Disease Quarterly is published by the Gluck Equine Research Center at the University of Kentucky.
The International Collating Centre, Newmarket, United Kingdom, and other sources reported the following disease outbreaks.
The Republic of South Africa (RSA), the Kingdom of Eswatini (SZ), and Thailand reported outbreaks of African horse sickness (AHS). AHS was confirmed in all nine provinces in the RSA, with the majority of cases in Gauteng Province. A single case was recorded in SZ. Outbreaks of AHS continued in Thailand, with multiple cases confirmed in 11 provinces.
Estonia, France, Germany, the Netherlands, the UK and the USA reported outbreaks of equine influenza ranging from one (Estonia), two (Germany), three (UK), four (France and the Netherlands), to at least five in many states (USA), where the disease is endemic. Although diagnosed primarily in unvaccinated or partially vaccinated horses, isolated cases were also seen in vaccinated animals.
Strangles is considered endemic in most countries with outbreaks reported from Belgium (one), France (seven), the Netherlands (16), Switzerland (four), and the USA (38 outbreaks in 17 states).
Equine herpesvirus type 1 (EHV-1)-related diseases are believed endemic in most countries and were confirmed by Belgium, Canada, France, Germany, Ireland, Japan, the Netherlands, the UK and the USA. Respiratory disease outbreaks were recorded by Belgium (two), France (two), Ireland (eight), Japan (one), the Netherlands (one), the UK (two) and the USA (one). EHV-1 abortion was reported by France (two outbreaks, single cases), Germany (one case), Japan (three outbreaks, one or two cases apiece), the Netherlands (two outbreaks, one involving two cases and a case of neonatal mortality, and another, a single case), the UK (three outbreaks, one involving multiple cases of respiratory disease, one neonatal mortality and three of neurologic disease; a second, involving three cases of neonatal mortality; and a third, a case of neonatal mortality). EHV-1 neurologic disease was confirmed by Canada (three outbreaks, one involved three cases; another, a single case; and a third, five cases with three having to be euthanized), and the USA (11 outbreaks in eight states, the majority were single cases).
Numerous countries reported equine herpesvirus type 4 (EHV-4) respiratory disease; outbreaks ranged from one (Belgium, Switzerland), four (Ireland), five (the Netherlands), to eight (France). France also reported a case of EHV-4 abortion.
Single cases of equine infectious anemia were recorded by Canada, Germany, and Hungary. The USA recorded three outbreaks, each involved one or two cases.
Equine piroplasmosis cases were reported by the RSA (where the disease is endemic) and New Zealand (a single case in an imported mare).
The USA recorded four cases of Tyzzer’s disease caused by Clostridium piliforme and also two cases of equine parvovirus associated hepatitis.
The UK detected Taylorella equigenitalis in an imported stallion.
Equine coital exanthema (equine herpesvirus type 3 infection) was diagnosed by France (one case) and the USA (three cases).
Belgium reported a case of leptospiral abortion and two cases of abortion caused by Streptococcus zooepidemicus.
Nocardioform placentitis/abortion was diagnosed by the USA, with 24 cases confirmed in Kentucky and 27 in Pennsylvania. Amycolatopsis spp. were implicated in the majority of cases.
The USA reported 13 cases of salmonellosis, the majority involving Serogroup B isolates.
Rotavirus diarrhea in foals was diagnosed by France (14 outbreaks, mostly single cases of infection) and the USA (78 cases, most involving 60-90 day old foals). A subset of 67 cases comprised 31 of the G3 genotype, 21 of the G14 genotype and 15 involving both genotypes.
Clostridium perfringens was reported in 12 foals and Clostridium difficile in seven foals by the USA.
The USA confirmed two fatal cases of Eastern equine encephalomyelitis in Florida and two cases of West Nile virus encephalitis, one in California and the other in Florida; one was euthanized.
A total of 71 cases of equine encephalosis were confirmed in seven provinces of the RSA.
The USA confirmed re-emergence of vesicular stomatitis in New Mexico in mid-April. The disease was subsequently confirmed in Arizona, Texas, Kansas and Nebraska. Of 107 affected premises, 103 were equine only premises and four cattle premises. The Indiana serotype was involved in all but seven premises in Texas where the New Jersey serotype was implicated.
Outbreaks of Rhodococcus equi associated diseases were reported by the USA. The number of recorded outbreaks is not considered reflective of the true incidence of the disease.