Officials have reported Madera County’s first and the state’s fifth confirmed equine WNV case for 2019. | Photo: Wikimedia Commons

The California Department of Food and Agriculture (CDFA) confirmed on Aug. 28 that an unvaccinated yearling Andalusian stallion presented with clinical signs of West Nile virus (WNV), including ataxia (incoordination), drooling, fever, and lethargy, on Aug. 18. The colt was tested using IgM-capture ELISA. By the confirmation date, the attending veterinarian reported the horse still displayed signs of ataxia but had received supportive care and improved.

This diagnosis marks the first confirmed case of equine West Nile virus in Madera County for 2019 and the fifth statewide, with other affected counties including Fresno, Kern, San Bernardino, and Stanislaus.

Seventy-five percent of the WNV cases confirmed in California are typically reported in August and September, with the first case being reported in late July or early August most years, said Katie Flynn, BVMS, MRCVS, equine staff veterinarian with the CDFA. In 2019 the first case was reported on Aug. 12