Identification and molecular characterization of Notoedres spp. from notoedric mange cases in four species of mammals from Florida, USA.

The objective of this study was to characterize <i>Notoedres</i> from Florida, USA and to determine if rabbits and squirrels share the same <i>Notoedres</i> species. From July 2022-November 2024, 19 suspected mange (i.e., alopecia and crusty lesions) cases were identified in 16 eastern cottontail rabbits (<i>Sylvilagus floridanus</i>), an eastern gray squirrel (<i>Sciurus carolinensis</i>), a marsh rabbit (<i>Sylvilagus palustris</i>), and a northern raccoon (<i>Procyon lotor</i>) in Florida. Most were in poor nutritional condition with multifocal alopecia and hyperkeratosis. Histologically, mites were noted in the variably hyperkeratotic stratum corneum with associated serocellular crusts and epidermal hyperplasia. Mites from rabbits and the squirrel were identified as <i>Notoedres centrifera</i> and the raccoon was infested with <i>Notoedres cati</i>. ITS-2 sequences from the squirrel and 11 cottontail rabbits were identical and 100 % similar to a <i>N. centrifera</i> sequence from a Florida cottontail rabbit. The other six <i>N. centrifera</i> sequences from the marsh rabbit and five cottontail rabbits matched those from a Florida marsh rabbit and a Kansas fox squirrel (<i>Sciurus niger</i>). The <i>N. cati</i> ITS-2 sequence was 100 % similar to <i>N. cati</i>. The <i>N. centrifera</i> COI sequences were more variable and fell into two groups that were 79.5 % and 79.8 % similar to <i>S. scabiei</i>. The raccoon <i>N. cati</i> COI sequence was 85.1 % (582/684) and 84.1 % (575/684) similar to Group 1 and Group 2 of <i>N. centrifera</i>, respectively, and 80.3 % similar to <i>S. scabiei</i>. Overall, these data may indicate that notoedric mange is endemic in rabbits and squirrels in Florida, confirm raccoons as hosts for <i>N. cati</i>, and highlight the utility of molecular characterization in mite speciation. Additionally, new sequences of <i>Notoedres</i> were generated that will facilitate future phylogenetic analyses. The biodiversity and ecosystem impacts of notoedric mange in Florida are currently unknown, but this research indicates a need for further field-based surveys to assess these potential risks.