A Survey of Tick Species in Pennsylvania Elk Populations

Winter Tick (Dermacentor albipictus)-Associated Dermatitis in a Wild Elk (Cervus canadensis) in Pennsylvania, USA

Calvente E, Chinnici N, Brown J, Banfield JE, Brooks JW, Yabsley MJ. Winter Tick (Dermacentor albipictus)-Associated Dermatitis in a Wild Elk (Cervus canadensis) in Pennsylvania, USA. J Wildl Dis. 2020 Jan;56(1):247-250. Epub 2019 Sep 4. PMID: 31483708.

Abstract

In 2017, a male elk (Cervus canadensis) was found dead in Pennsylvania, US. The elk was in poor nutritional condition and had alopecia and ulcerative dermatitis throughout the neck and dorsum region associated with severe Dermacentor albipictus infestations. Histologically, there was severe chronic-active dermatitis with hyperkeratosis and crust formation.

---

Prevalence of Winter Ticks (Dermacentor albipictus) in Hunter-Harvested Wild Elk (Cervus canadensis) from Pennsylvania, USA (2017-2018)

Calvente E, Pelletier S, Banfield J, Brown J, Chinnici N. Prevalence of Winter Ticks (Dermacentor albipictus) in Hunter-Harvested Wild Elk (Cervus canadensis) from Pennsylvania, USA (2017-2018). Vet Sci. 2020 Nov 12;7(4):177. doi: 10.3390/vetsci7040177. PMID: 33198183; PMCID: PMC7712540.

Abstract

Winter ticks (Dermacentor albipictus) are an aggressive one-host tick that infest a wide-diversity of ungulates. Infestations can result in anemia, alopecia, emaciation, and death. Most notably, the winter tick has caused negative impacts to moose (Alces alces) populations in the northeast United States and Canada. Winter ticks have been identified on other cervid species, including deer (Odocoileus virginianus) and elk (Cervus canadensis), which generally results in low tick burdens and mild or no disease. Recently, however, a wild yearling bull elk in Pennsylvania was found dead as a result of severe winter tick infestation. To obtain baseline data on winter ticks in wild elk in Pennsylvania, we collected 1453 ticks from 190 hunter-harvested wild elk between 2017-2018. Of the 204 harvested elk, 94.3% (190/204) had ticks collected for this study and none of the sampled elk had evidence of winter-tick associated disease. The average tick burden was 7.7 ticks/elk and average winter tick load on all elk was 0.5. Results of this study indicate that winter ticks do infest wild elk in Pennsylvania. However, during the fall months, the tick burden is low and rarely associated with lesions. These data herein serve as a baseline to monitor winter tick populations over time.

---

Surveillance for Babesia odocoilei in Hunter-Harvested Wild-Elk (Cervus elaphus canadensis) from Pennsylvania, USA (2016–2017)

Calvente EJ, Steber C, Brown J, Brown H, Banfield J, Chinnici N. Surveillance for Babesia odocoilei in Hunter-Harvested Wild-Elk (Cervus elaphus canadensis) from Pennsylvania, USA (2016-2017). Vet Sci. 2021 May 29;8(6):94. doi: 10.3390/vetsci8060094. PMID: 34072484; PMCID: PMC8226896.

Abstract

Babesia odocoilei is a tick-borne protozoal parasite which infects the erythrocytes of members of the families Cervidae and Bovidae. Infection can result in hemolytic anemia, lethargy, anorexia, and death. The reservoir host of B. odocoilei is the white-tailed deer (Odocoileus virginianus ); however, infections with overt disease have only been documented in reindeer (Rangider tarandu tarandus ), caribou (Rangider tarandu caribou ) and captive elk (Cervus elaphus canadensis ). Infected elk may remain asymptomatic, creating the risk for dissemination of the pathogen when elk are relocated. Additionally, infected asymptomatic elk may contribute to the spread of B. odocoilei in the local wildlife/captive population via feeding ticks. Information regarding endemic regions of B. odocoilei infection is limited due to frequent asymptomatic infections and a lack of targeted surveillance of B. odocoilei in wildlife. To obtain data on B. odocoilei infection in wild elk in Pennsylvania, we tested blood samples collected from 190 hunter-harvested wild elk between 2016 and 2017. Of the 190 blood samples tested, 18.4% (35/190) tested positive for Babesia spp. Genetic sequencing of the positive samples showed a 98.0–100.0% match for B. odocoilei . No other Babesia species were identified. Results of this study documents B. odocoilei infection within hunter-harvested wild elk from Pennsylvania.

For more information on this project please email wildlifedna@esu.edu.