The International Thoroughbred Breeders Federation, International Collating Centre, Newmarket, United Kingdom, and other sources reported the following equine disease events.
Thailand and Malaysia recorded outbreaks of African horsesickness (AHS). Thailand reported outbreaks in August (one case in a horse) and September (two cases in captive Chapman’s zebras). Malaysia confirmed its first ever incursion of AHS in August; five horses on a single premises. Affected equids in the outbreaks in both countries were euthanized.
Belgium, France, Germany, Italy, Sweden and the USA confirmed outbreaks of equine influenza. These ranged from one (Belgium, France and Italy), three (Sweden), four (Germany), to at least nine in the USA, where the disease is endemic.
Strangles is considered endemic in many countries, with outbreaks reported from Belgium (two), Canada (one), France (nine), the Netherlands (12, one involving 15 cases), Switzerland (eight), and the USA (41 outbreaks in 17 states, the majority with multiple cases).
Equine herpesvirus type 1 (EHV-1) related diseases are endemic in most countries. Cases were confirmed in France, Japan, Republic of South Africa (RSA), Sweden, Switzerland, the UK, and the USA. Single outbreaks of respiratory disease were recorded in France, RSA, and the UK. One case of EHV-1 abortion was confirmed in Japan in an unvaccinated mare. EHV-1 neurologic disease was reported by Sweden (single case), Switzerland (three outbreaks), and the USA (seven outbreaks involving five states, with two outbreaks in California and Maine); the majority involved single cases.
Equine herpesvirus type 4 (EHV-4) respiratory disease was recorded by France (20 outbreaks, mostly single cases), Japan (one outbreak involving eight unvaccinated horses) and the Netherlands (five outbreaks, one involving seven 4-5 month old foals). Switzerland reported an outbreak of EHV-4 neurologic disease.
Belgium and the USA confirmed cases of equine herpesvirus types 2 and/or 5. Infection with EHV-2 was diagnosed in a 2-month-old foal in Belgium, and numerous infections by either virus were diagnosed in several states in the USA, some associated with respiratory disease.
A case of adenovirus infection was reported in a foal in Ireland.
The USA confirmed four outbreaks of equine infectious anemia, three in Texas, one involving two cases, and one in Georgia. Three outbreaks involved single cases.
Equine piroplasmosis was recorded in Finland (one case), RSA (disease is endemic) and Switzerland (one outbreak).
Denmark reported the isolation of Taylorella equigenitalis, the cause of contagious equine metritis, from three stallions.
Equine coital exanthema (equine herpesvirus type 3) was diagnosed in Argentina (two outbreaks involving 29 Thoroughbreds) and the USA (one case).
Belgium confirmed single cases of leptospiral abortion on two premises. A case of Leptospira-associated recurrent uveitis was diagnosed in a stallion by France.
Salmonellosis was reported by Switzerland (two outbreaks) and the USA (10 cases, two involving serogroup C1, five serogroup D1, and three weren’t serogrouped).
France confirmed 19 outbreaks of rotavirus diarrhea in foals, the majority were single cases. A total of 17 cases were diagnosed by the USA, the majority in 60- to 90-day-old foals in Kentucky involving G3 and/or G14 genotypes.
One case of proliferative enteropathy caused by Lawsonia intracellularis was reported by the USA.
Canada (four outbreaks, all single cases) and the USA (17 outbreaks in 10 states, one involving 10 cases) confirmed outbreaks of equine neorickettsiosis (Potomac Horse Fever).
Eastern equine encephalomyelitis (EEE) was reported by Canada (two outbreaks, each involving single cases) and the USA (104 cases in 11 states), with highest numbers in Michigan (33), Wisconsin (20), and Florida (13).
West Nile encephalitis was recorded by Canada (one case), France (three outbreaks, one case each), Germany (eight outbreaks), Hungary (one outbreak), Italy (nine outbreaks), Portugal (one case), Spain (13 outbreaks, three were single cases), and the USA (27 cases in seven states, four on one premises).
A case of rabies was confirmed in a Warmblood horse in Maryland, USA.
Switzerland confirmed two outbreaks of Borna disease, and one outbreak of anaplasmosis.
Vesicular stomatitis continued to spread in the USA in the third quarter of 2020, extending to Arkansas, Missouri and Oklahoma, in addition to five previously reported states. A total of 198 equine outbreaks were recorded, all associated with the Indiana serotype.
Rhodococcus equi related diseases were confirmed by the USA.