<P> Several wild boars from Leon Springs and the San Antonio, Saint Louis and San Diego Zoos were released in the Powder Horn Ranch in Calhoun County, Texas, in 1939 . These specimens escaped and established themselves in surrounding ranchlands and coastal areas, with some crossing the Espiritu Santo Bay and colonising Matagorda Island . Descendants of the Powder Horn Ranch boars were later released onto San José Island and the coast of Chalmette, Louisiana . </P> <P> Wild boar of unknown origin were stocked in a ranch in the Edwards Plateau in the 1940s, only to escape during a storm and hybridise with local feral pig populations, later spreading into neighbouring counties . </P> <P> Starting in the mid-80s, several boars purchased from the San Diego Zoo and Tierpark Berlin were released into the United States . A decade later, more specimens from farms in Canada and Białowieża Forest were let loose . In recent years, wild pig populations have been reported in 44 states within the US, most of which are likely wild boar - feral hog hybrids . Pure wild boar populations may still be present, but are extremely localised . </P> <P> Wild boars are known to host at least 20 different parasitic worm species, with maximum infections occurring in summer . Young animals are vulnerable to helminths like Metastrongylus, which are consumed by boars through earthworms, and cause death by parasitising the lungs . Wild boar also carry parasites known to infect humans, including Gastrodiscoides, Trichinella spiralis, Taenia solium, and Balantidium coli . Wild boar in southern regions are frequently infested with ticks (Dermacentor, Rhipicephalus, and Hyalomma) and hog lice . The species also suffers from blood - sucking flies, which it escapes by bathing frequently or hiding in dense shrubs . </P>

Where are wild boars found in the us