Health assessments and pathogen surveys in wildlife are critical for gauging population-level risks. Recent concerns associated with ophidiomycosis, caused by the fungus Ophidiomyces ophidiicola (Oo), have brought needed attention to snake conservation. We evaluated the health of native snake species in the southeastern United States through physical examinations and multipathogen surveillance targeting Cryptosporidium spp., Hepatozoon spp., Mycoplasma spp., Oo, Raillietiella orientalis (Ro), Salmonella spp., and serpentoviruses. We hypothesized that apparent ophidiomycosis (skin lesions present and qPCR detection of Oo) would be positively associated with coinfection detection, and that pathogen detection prevalence would vary spatiotemporally and among snake species. We assessed pathogen and disease prevalence through monthly sampling from May 2022 to May 2024 (via full-body skin swabs, choanal swabs, cloacal swabs, blood, and fecal collection, and physical examinations) at wetland sites in Volusia County, Florida, and Jasper County, South Carolina. We opportunistically sampled snakes from a site in Athens-Clarke County, Georgia, and included diagnostic cases submitted to the Southeastern Cooperative Wildlife Disease Study from 2021 to 2024. In total, we sampled 509 individuals with 49 recaptures, representing 29 species. We included 61 carcasses, comprising 56 individuals (33 collected opportunistically) and five recaptures. We detected Salmonella enterica in 62.6% (306/489), Hepatozoon spp. in 53.4% (205/384), Mycoplasma spp. in 17.5% (78/445), Oo in 16.1% (82/508), and Cryptosporidium spp. in 2.0% (10/489). Detection of Ro was limited to snakes in Florida, with a detection prevalence of 12.7% (37/292). No serpentoviruses were detected (n = 447). Overall coinfection prevalence was 44.0% (219/498) and was strongly predictive of apparent ophidiomycosis (p < 0.0001). Mycoplasma spp. and Cryptosporidium spp. were nearly exclusively detected in snakes from Florida. Seasonal trends were seen in the detection of Mycoplasma spp. (p = 0.0075), Oo (p = 0.0475), and S. enterica (p = 0.0295). Detection of Oo (p = 0.0002) or Ro (p = 0.0200) was negatively associated with nutritional condition scores. Increased detection risks of Oo (p = 0.0479) and apparent ophidiomycosis (p = 0.0148) were observed primarily in pygmy rattlesnakes (Sistrurus miliarius), supported by severe associated pathology, indicating increased conservation risks. This health assessment enhances understanding of infectious agents circulating in free-ranging snakes in the southeastern United States and establishes baseline parameters to inform conservation management.
