In Alberta, rabies has been diagnosed in the following bat species:
- Big brown bat (Eptesicus fuscus)
- Hoary bat (Lasiurus cinereus)
- Little brown bat (Myotis lucifugus)
- Silver-haired bat (Lasionycteris noctivagans)
- Western small-footed bat (Myotis ciliolabrum) (a single individual from Alberta)
Bat Collection and Testing
Most rabid bats are collected in August and September. The number of infected individuals differs from year to year and among species, but is consistently low (4 to 6 rabid bats each year).
Bats collected randomly from nursery colonies by Fish and Wildlife Division personnel rarely are infected with rabies (1 of 1500 tested since 1979). This tells us that the virus is present in the general bat population but occurs at extremely low prevalence.
Most of the bats collected by the public and submitted for rabies testing are collected because they behave abnormally and/or appear sick (suspect bats). In spite of this, only a few of these bats have rabies.
However, 13 rabid bats were collected from one roost in an occupied house near Penhold in 1973. No similar cluster of cases has been found since then.
Ongoing surveillance for rabies infections in bats occurs throughout Alberta. Any bat found on the ground or that bites a person can be submitted to any veterinary or Fish and Wildlife office.
Prevalence of Rabies Infection by Bat Species
- The prevalence of rabies in little brown bats, by far the most common bat species in Alberta, decreased significantly in the 1970s and the virus all but disappeared in this species since then.
- The prevalence of rabies in suspect big brown bats (those bats that are acting strange or on the ground) is consistently 5% to 10% of the big brown bats tested.
- The prevalence in suspect silver-haired bats is erratic, ranging from 0% to 18%. Prevalence is affected by the low number of these bats tested.
- The number of hoary bats submitted for testing is too low to establish the rate of infection. Very few rabid hoary bats are found.
Distribution of Rabid Bats
Although the number of rabid bats is low, they can occur throughout the province and generally reflect the presence of people. Sick or dead bats in uninhabited areas largely go unnoticed.
- A higher number of bats collected in southern Alberta is associated with increased public awareness and concern about rabies in this area.
- The pattern of rabies infection in insectivorous bats is relatively stable and remains consistent across Canada and the United States. There have been no significant changes in the occurrence of rabies in bats in Alberta since the data reported in the 1970s.
- Each year, a few rabid bats are found somewhere in Alberta. The numbers remain low (less than 6 rabid bats each year) and the distribution largely reflects human activities, as it is necessary for a bat to be found and sent in for rabies testing.
The Canadian Food Inspection Agency (CFIA) conducts all rabies testing in Canada. To view the results of such testing, visit the CFIA website at:
While the risk of contracting rabies from a bat is low in Alberta, it is prudent to take preventative measures, especially if you must handle a live bat. See rabies risk and prevention information at:
Posted: Jan 13, 2011