Taenia ovis infection and its control: a Canadian perspective

Distributed worldwide, Taenia ovis infection is responsible for the condemnation of sheep carcasses in many countries. This review highlights the programme used in New Zealand to successfully control T. ovis in sheep, and discusses how similar approaches may be modified for use in Canada, given what is currently known about the epidemiology of T. ovis. The lifecycle of the parasite is well known, involving dogs as the definitive host and sheep or goats as the intermediate host. An effective vaccine does exist, although it is not presently commercially available. In New Zealand an industry-based, non-regulatory programme was created to educate producers about T. ovis and necessary control strategies, including the need to treat farm dogs with cestocides regularly. This programme resulted in a substantial decrease in the prevalence of T. ovis infections between 1991 and 2012. Historically, T. ovis was not a concern for the Canadian sheep industry, but more recently the percentage of lamb condemnations due to T. ovis has increased from 1.5% in 2006 to 55% in 2012. It has been suggested that coyotes may be transmitting T. ovis, but this has not been confirmed. Recommendation are made for the Canadian sheep industry to adopt a control programme similar to that used in New Zealand in order to reduce the prevalence of T. ovis infection.