RESUMEN
Giraffe skin disease (GSD) is an emerging disease of free-ranging giraffe recognized in the last 25 years in several species, including the critically endangered Nubian giraffe (Giraffa camelopardalis camelopardalis) of Uganda. Identifying the cause of GSD and understanding its impact on health were deemed paramount to supporting these vulnerable populations. Sixty-four giraffes were immobilized in Murchison Falls National Park, Uganda, from 2017 to 2019, and GSD lesions were opportunistically biopsied. Fifty-five giraffes (86%) had GSD lesions on the neck, axilla, chest, and cranial trunk. Lesions were categorized into early, intermediary, and dormant stages based on gross and histological characteristics. Early lesions were smaller, crusted nodules with eosinophilic and pyogranulomatous dermatitis and furunculosis. Intermediary lesions were thick plaques of proliferative and fissured hyperkeratosis and acanthosis with dense dermal granulation tissue and severe eosinophilic and granulomatous dermatitis. Lesions appeared to resolve to dormancy, with dormant lesions consisting of hairless plaques of hyperkeratosis with dermal scarring and residual inflammation. The periphery of early and intermediary lesions included follicular granulomas containing adult filarid nematodes, with myriad encysted microfilariae in the superficial dermis. Stage L3 larvae were common in early and intermediary lesions, and dormant lesions had remnant encysted microfilariae with no adult or stage L3 larvae. Nematodes were morphologically and genetically novel with close identity to Stephanofilaria spp. and Brugia malayi, which cause infectious filariasis. Identification of potential insect vectors, long-term monitoring of GSD lesions, and evaluating response to therapy is ongoing in the efforts to help conserve the Nubian giraffe.
Asunto(s)
Dermatitis , Filariasis , Jirafas , Enfermedades de la Piel , Animales , Dermatitis/patología , Dermatitis/veterinaria , Filariasis/patología , Filariasis/veterinaria , Piel/patología , Enfermedades de la Piel/patología , Enfermedades de la Piel/veterinariaRESUMEN
Cattle fever ticks, Rhipicephalus microplus and R. annulatus have been eradicated from the United States and inspectors from the U.S. Department of Agriculture (USDA), Animal Plant Health Inspection Service (APHIS), Cattle Fever Tick Eradication Program (CFTEP) monitor the quarantine zone along the Texas border to prevent the introduction of livestock carrying cattle fever ticks from Mexico. Stray livestock apprehended by CFTEP in the zone are checked for ticks and tested for infectious disease-causing pathogens but are not evaluated for evidence of infection with tick-borne pathogens. We tested blood samples collected from stray cattle by CFTEP inspectors for evidence of infection with tick-borne pathogens. As a comparison group representing U.S. resident cattle, we tested blood samples that had been sent to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for unrelated testing. Both sets of blood samples were evaluated using the same specific and broad-spectrum PCR assays. For the border cattle the overall prevalence of infection with one or more tick-borne pathogen was 58.5 % (79/135) with many co-infections, including 30 cattle positive for Babesia bovis and/or Babesia bigemina (22.2 %) and 77 cattle positive for Anaplasma marginale (57 %), three of these animals were also positive for Borrelia theileri. No resident cattle represented by the TVMDL samples were infected with either of the Babesia spp., or with Borrelia theileri, but three were positive for Theileria orientalis and 7.3 % (7/96) were positive for A. marginale. These data show that cattle originating in Mexico have a higher prevalence of infection with tick-borne pathogens relative to resident U.S. cattle and specifically, a proportion are infected with bovine Babesia, which is absent from U.S. cattle populations. Consequently, these stray cattle may be a reservoir of tick-borne pathogens and if populations of Boophilus ticks become reestablished in areas where they had previously been eradicated, could pose a significant risk to the U.S. Cattle industry.