Dogs are sending us an early warning signal about the spread of a potentially deadly tapeworm in North America.
The tapeworm, Echinococcus multilocularis, is normally found in rodents and other wild animals, including coyotes and foxes, but can spill over into cats and dogs — and even humans.
In July, as I was warning veterinarians about the risk of E. multilocularis in dogs — and cautioned that human cases couldn’t be far behind — news broke that four people in Alberta had been infected by the parasite.
Not since 1928 had a domestically acquired human case of the tapeworm been reported in Canada and there has been only one human case reported in the contiguous United States.
The disease is rare in humans, even in areas of Asia and Europe where it is well established. The number of cases in people is linked to its presence in animal hosts. In Switzerland, for example, human cases almost doubled between 1960 and 2004 — preceded by a rise in the number of infected foxes, the main hosts for the parasite in Europe.
