Survey for selected pathogens in Philippine deer (Rusa marianna) from Guam, Marianna Islands, USA

Philippine deer (Rusa marianna), native to the Philippine Islands, were introduced to Guam in the late 1700's. Dense populations have become established throughout the island where they cause damage to native plant communities resulting in habitat degradation. In addition, cervids can serve as reservoirs for important pathogens of livestock and people. From February-March 2015, blood, tissue and ectoparasite samples were collected from 132 free-ranging Philippine deer on Guam. Data from 10 deer sampled in 1997 were also analyzed. Deer were negative for antibodies to many of the pathogens assessed including epizootic hemorrhagic disease virus, parainfluenza 3 virus, bovine viral diarrhea virus, bovine herpesvirus 1, and Brucella spp.; however, two (2%) and nine (7%) deer were seropositive for bluetongue virus and Toxoplasma gondii, respectively. Five (4%) deer had low titers (1:100) to Leptospira interrogans serovars Bratislava (n = 4), Canicola (n = 2), and Icterohaemorrhagiae (n = 1). None of the kidney samples from Leptospira-seropositive deer were immunohistochemically positive for leptospires. No nematodes or trematodes were detected in lungs, abdomen, abomasum or liver. A few deer had 1-4 Cooperia spp. in the small intestine, although very small nematodes may have not been captured by the #100 mesh used for screening. Of the 105 deer evaluated for ectoparasites, 90.5% were infested with Rhipicephalus microplus. Tick burdens were generally high and classified as low ( < 500 ticks) (59% of infested deer), medium (500-1000 ticks) (22%), and high ( > 1000 ticks) (19%). Molecular testing of blood samples for Babesia spp. was negative, but 11 (8%) deer were positive for Anaplasma spp. Sequence analysis revealed that deer were infected with three species of Anaplasma including A. marginale, A. phagocytophilum, and an Anaplasma sp. similar to A. platys. Finding A. marginale, T. gondii, Leptospira and heavy burdens of ticks in Philippine deer is of economic and public health importance.