Equine Health Update EHU 2020 Issue 01 | Page 29

Equine Disease Quarterly | EQUINE arteritis virus infection. Two outbreaks were confirmed by France, represented by single cases of abortion and two cases of equine viral arteritis in one of the outbreaks. Poland recorded one outbreak involving three cases of equine viral arteritis. The UK confirmed infection in a subclinical carrier stallion. A single case of Lawsonia intracellularis infection was reported by the USA. Equine infectious anemia was reported by Canada (three outbreaks involving single cases, one of which was clinical), France (two outbreaks, each involving single cases), and the USA (14 outbreaks, one of which involved 17 horses). West Nile encephalitis was reported by Austria (two cases), Brazil (three cases), Canada (one case), France (four cases), Germany (eight cases), Greece (two cases), Italy (one case), and the USA (34 cases, of which 14 were in California). The USA confirmed five outbreaks of anthrax, all in a high-risk region of Texas.RSA reported that equine piroplasmosis was endemic in the country, with 29 cases recorded during the period under review. RSA confirmed three cases of equine encephalosis. Contagious equine metritis was confirmed by Denmark (case in a stallion), France (two outbreaks, one involving a carrier stallion and another causing metritis and abortion in a mare), and Germany (infection in a mare). Three outbreaks of salmonellosis were recorded in the USA. The USA reported 25 cases of equine neorickettsiosis involving three states. The vast majority were in July and August in Kentucky. Clostridial enterocolitis was recorded in the USA, with confirmation of 13 cases of Clostridium perfringens Type A toxin genotype and 15 cases of C. difficile. France reported eight outbreaks of rotavirus infection, six involving single cases and two with two cases. The USA confirmed 22 cases of infection, principally in Kentucky, the preponderance associated with the G14 virus genotype and a few involving both G3 and G14 genotypes. Eastern equine encephalomyelitis was recorded in the USA with 76 cases confirmed in the third quarter, the majority in Florida and Michigan. Vesicular stomatitis (Indiana serogroup) was confirmed on premises in seven states in the USA: Colorado, Nebraska, New Mexico, Oklahoma, Texas, Utah and Wyoming. A total of 1095 affected premises were identified during the period under review. Rhodococcal-related disease was reported by Belgium (one case) and the USA, in which the disease is endemic. Twenty cases were diagnosed in Kentucky; this is considered a significant underestimate of the actual incidence. Germany and Switzerland reported single cases of ehrlichiosis. Inbreeding and Genomics Inbreeding has played a key role in the improvement of livestock breeds, resulting in more uniform populations with highly specialized performance traits. Selection for desirable traits entails identifying individuals with superior performance and often mating them to relatives (inbreeding) who possess the same superior traits. The goal of this practice is to increase the frequency of the • Volume 22 Issue 01 | March 2020 • 29