Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 25, Number 4—April 2019
Research Letter

Epizootic Hemorrhagic Disease in White-Tailed Deer, Canada

Article Metrics
citations of this article
EID Journal Metrics on Scopus
Samantha E. AllenComments to Author , Jamie L. Rothenburger1, Claire M. Jardine, Aruna Ambagala, Kathleen Hooper-McGrevy, Nicole Colucci, Tara Furukawa-Stoffer, Stacey Vigil, Mark Ruder, and Nicole M. Nemeth2
Author affiliations: University of Guelph and Canadian Wildlife Health Cooperative, Guelph, Ontario, Canada (S.E. Allen, J.L. Rothenburger, C.M. Jardine, N.M. Nemeth); Canadian Food Inspection Agency, Winnipeg, Manitoba, Canada (A. Ambagala, K. Hooper-McGrevy); Canadian Food Inspection Agency, Lethbridge, Alberta, Canada (N. Colucci, T. Furukawa-Stoffer); University of Georgia, Athens, Georgia, USA (S. Vigil, M. Ruder, N.M. Nemeth)

Cite This Article


Epizootic hemorrhagic disease affects wild and domestic ruminants and has recently spread northward within the United States. In September 2017, we detected epizootic hemorrhagic disease virus in wild white-tailed deer, Odocoileus virginianus, in east-central Canada. Culicoides spp. midges of the subgenus Avaritia were the most common potential vectors identified on site.

Epizootic hemorrhagic disease viruses (EHDVs) and bluetongue viruses (BTVs) are Culicoides spp. midge–transmitted orbiviruses that represent an imminent threat to the health of ruminant livestock and wildlife. For susceptible ruminants, EHDV and BTV infections can result in high rates of illness and death, leading to severe economic hardship to the agricultural sector (1). These viruses have a historical geographic range of 40°N–50°N and 35°S, following the distribution of the Culicoides vectors. However, the epidemiology of these pathogens is changing, with decades of northward expansion into areas of Europe and North America with immunologically naive hosts (13).

In Canada, EHDV has rarely and sporadically been detected in the southern portions of British Columbia, Alberta, and Saskatchewan (4). We report the detection of EHDV in white-tailed deer, Odocoileus virginianus, in east-central Canada, providing further evidence of the northern range expansion of orbiviruses within North America.

On September 7, 2017, two wild white-tailed deer carcasses were found in a seminatural area adjacent to a river and ravine in London, Ontario, Canada (42.9849°N, 81.2453°W). The carcasses were submitted for diagnostic investigation to the Ontario-Nunavut region of the Canadian Wildlife Health Cooperative. Both deer had gross lesions consistent with epizootic hemorrhagic disease, including multiorgan petechial and ecchymotic hemorrhages on serosal surfaces (5). Spleen, lung, and liver samples from both deer were submitted to the National Centre for Foreign Animal Diseases in Winnipeg. All samples were positive for EHDV genomes by reverse transcription PCR (RT-PCR) (6). The serotype of the virus was identified by serotype-specific conventional RT-PCR followed by Sanger sequencing. EHDV-2 was isolated from spleen samples of both deer. Two additional deer carcasses were identified in the area but were not submitted for diagnostic testing. Tissues from an additional 14 deer carcasses that originated in southern Ontario during September 23–November 28, 2017, showed negative results for EHDV by RT-PCR, as part of enhanced surveillance conducted by the Ontario Ministry of Natural Resources and Forestry and the Canadian Wildlife Health Cooperative.

In addition, we conducted serosurveillance across southern Ontario in the fall of 2017 with samples collected by private veterinarians. All live animal samples were collected by using protocols approved by the Animal Care Committee, University of Guelph (approval no. 3529). Cattle were from Chatham-Kent County, adjacent to Middlesex County, and were born and had lived their whole lives in Canada. Results revealed 15 cattle with antibodies to EHDV-2 by ELISA and serum neutralization tests (S.E. Allen, unpub. data).

We also conducted a targeted survey for adult Culicoides midges in the area of the white-tailed deer deaths by using four 2770 UV LED CDC light traps (BioQuip Products, for 16 trap-nights during September 9–13, 2017. We taxonomically identified 31 individual Culicoides spp. midges (7), including subgenus Avaritia (n = 22), C. haematopotus (n = 5), C. stellifer (n = 2), C. venustus (n = 1), and C. crepuscularis (n = 1) midges.

The northern expansion of EHDV and BTV in the midwestern and northeastern regions of the United States in recent years (1,8) has increased the likelihood of incursion into eastern Canada. The EHDV occurrence in white-tailed deer in Ontario we report supports the need to maintain vigilance. Although this initial occurrence was limited spatially and temporally, future cases may be more widespread in wildlife and livestock. Furthermore, this localized EHDV-2 occurrence was within 72 km of the US border of Michigan and coincided with concurrent and widespread EHDV-2 and EHDV-6 outbreaks across much of the eastern United States during July–October, 2017 (D.E. Stallknecht, University of Georgia, pers. comm, 2018 Jan 10).

EHDV may have been introduced to Ontario through the movement of infected vectors or ruminants, and its detection in Ontario may represent the northern edge of the EHDV outbreak in the eastern United States. Alternatively, low levels of previously undetected EHDV transmission may have been transient or ongoing across a wider region, including Ontario, for an unknown period. In either case, this event may preclude a much more widespread and higher impact EHDV outbreak, such as occurred with BTV in Europe and with EHDV in the United States (2,8).

We identified numerous Culicoides spp. midges at the site where the EHDV-infected white-tailed deer carcasses were recovered. However, C. sonorensis midges, the only confirmed EHDV vector species in North America (1,9), was not among these. This species was recently identified in Ontario (10), but the density and distribution of this species in the province, as well as its role in regional EHDV transmission, is currently unknown. Culicoides spp. composition within areas of past EHDV outbreaks varies widely; therefore, additional Culicoides spp. midges may serve as competent EHDV vectors. However, this possibility has not been confirmed (1,9). In addition to vector competence, the climatic limitations for the survival and successful breeding and establishment of current Culicoides spp. populations in the region remain to be investigated (1,8). These factors indicate the need for ongoing Culicoides spp. midge and deer mortality surveillance in the region.

Dr. Allen is a veterinarian and PhD candidate at the University of Guelph, Canada. Her research focuses on wildlife disease, specifically vector borne viruses and disease at the livestock–wildlife interface.



We thank the submitter for providing information on the deer cases and D. Cristo, C. Embury-Hyatt, and L. Shirose for assistance with sample submission and testing.

This study was funded by the Ontario Ministry of Agriculture, Food and Rural Affairs, University of Guelph Partnership (UofG2015-2212) and the Canadian Foundation for Innovation (RGPIN-2015-04088).



  1. Ruder  MG, Lysyk  TJ, Stallknecht  DE, Foil  LD, Johnson  DJ, Chase  CC, et al. Transmission and epidemiology of bluetongue and epizootic hemorrhagic disease in North America: current perspectives, research gaps, and future directions. Vector Borne Zoonotic Dis. 2015;15:34863. DOIPubMedGoogle Scholar
  2. Maclachlan  NJ. Global implications of the recent emergence of bluetongue virus in Europe. Vet Clin North Am Food Anim Pract. 2010;26:16371. DOIPubMedGoogle Scholar
  3. McVey  DS, Drolet  BS, Ruder  MG, Wilson  WC, Nayduch  D, Pfannenstiel  R, et al. Orbiviruses: a North American perspective. Vector Borne Zoonotic Dis. 2015;15:3358. DOIPubMedGoogle Scholar
  4. Pybus  MJ, Ravi  M, Pollock  C. Epizootic hemorrhagic disease in Alberta, Canada. J Wildl Dis. 2014;50:7202. DOIPubMedGoogle Scholar
  5. Howerth  EW, Stallknecht  DE, Kirkland  PD. Bluetongue, epizootic hemorrhagic disease, and other orbivirus-related diseases. In: Williams ES, Barker IK, editors. Infectious diseases of wild mammals. Ames (IA): Iowa State University Press; 2001. p. 82–9.
  6. Pasick  J, Handel  K, Zhou  EM, Clavijo  A, Coates  J, Robinson  Y, et al. Incursion of epizootic hemorrhagic disease into the Okanagan Valley, British Columbia in 1999. Can Vet J. 2001;42:2079.PubMedGoogle Scholar
  7. Wirth  WW, Dyce  AL, Peterson  BV. An atlas of wing photographs with a summary of the numerical characters of the Nearctic species of Culicoides (Diptera: Ceratopogonidae). Contrib Am Entomol Inst. 1985;22:146.
  8. Stallknecht  DE, Allison  AB, Park  AW, Phillips  JE, Goekjian  VH, Nettles  VF, et al. Apparent increase of reported hemorrhagic disease in the midwestern and northeastern USA. J Wildl Dis. 2015;51:34861. DOIPubMedGoogle Scholar
  9. Pfannenstiel  RS, Mullens  BA, Ruder  MG, Zurek  L, Cohnstaedt  LW, Nayduch  D. Management of North American Culicoides biting midges: current knowledge and research needs. Vector Borne Zoonotic Dis. 2015;15:37484. DOIPubMedGoogle Scholar
  10. Jewiss-Gaines  A, Barelli  L, Hunter  FF. First records of Culicoides sonorensis (Diptera: Ceratopogonidae), a known vector of bluetongue virus, in southern Ontario. J Med Entomol. 2017;54:75762.PubMedGoogle Scholar


Cite This Article

DOI: 10.3201/eid2504.180743

1Current affiliation: University of Calgary, Calgary, Alberta, Canada.

2Current affiliation: University of Georgia, Athens, Georgia, USA.

Table of Contents – Volume 25, Number 4—April 2019

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.



Please use the form below to submit correspondence to the authors or contact them at the following address:

Samantha E. Allen, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada

Send To

10000 character(s) remaining.


Page created: March 17, 2019
Page updated: March 17, 2019
Page reviewed: March 17, 2019
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.