Pet owners and sheep producers warned about tapeworm threat

UNSEEN THREAT Tapeworm eggs pass easily through many species and can lead to 
medical issues for humans and costly losses for livestock producers

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Here’s one more reason to hate coyotes.

The predators frequently carry tapeworms in their gut that can infect dogs and possibly humans. Tapeworms passed on by canine species can also result in sheep measles, a costly disease for sheep and goat producers.

One type of tapeworm found in coyotes, Echinococcus multilocularis, is receiving new attention thanks to the research of Alessandro Massolo, a University of Calgary wildlife ecologist with the faculty of veterinary medicine. The expert in canid parasites has been studying the prevalence of this species of tapeworm among Alberta’s urban coyote population, but his research has implications for rural residents.

When the tapeworms reproduce, a part of their body (called a proglottid) detaches and is excreted in the feces. Rodents eating scat can then become hosts, are weakened by fast-growing tapeworm larvae, and become easy prey for other coyotes, foxes, or worryingly, dogs. That puts humans at risk as the cycle continues and pet owners can inadvertently come into contact with little egg capsules when cleaning up after their dogs, or through petting them. Humans are not proper hosts for this type of tapeworm but can develop cysts on internal organs. The cysts will become a medically significant problem, and after years of incubation, the victim will often present like a liver cancer patient. Surgery will be undertaken to remove the cysts, and two years of chemotherapy follows to ensure the parasite is killed off. If the cysts are inoperable, chemotherapy alone can still be used.

It’s an expensive proposition, and very hard on the patient. Left untreated, the condition can become fatal. Although there has never been a case in Alberta, there has been one incidence in Manitoba and cases are more common in China and other countries.

A recent study found 23 of 91 urban coyotes necropsied had the E. multiocularis tapeworm and Massolo said both urban and rural pet owners need to take precautions.

“Don’t let your dog eat rodents,” said Massolo, adding rural dogs should be dewormed at least twice annually.

Owners must ask for tapeworm-specific deworming medication as common and over-the-counter roundworm medication will not work, he said.

Additionally, dog owners should always wash their hands after being in contact with feces and after grooming or washing their canine companions.

Sheep tapeworm

Another type of tapeworm can cause problems for sheep producers.

Once again, the danger comes from sheep grazing where feces containing tapeworm eggs are present. The eggs penetrate the intestines of sheep and goats, then travel through the bloodstream into muscle tissue. Cysts are then formed in the muscle tissue of the livestock, which can cause severe scarring once the animal’s immune system attacks the invading cysts, leaving marks reminiscent of the spotting rash of measles.

The cysts contain juvenile tapeworms, and are passed to coyotes or dogs feeding on deadstock.

Although humans cannot be infected by this tapeworm, it ruins the meat and with severe infestations, results in the entire carcass being discarded.

Controlling this tapeworm in infested livestock is difficult and it is recommended producer deworm dogs every two or three months if they’ve been exposed to an infected herd. Dogs should never be fed undercooked or raw sheep or goat meat — and proper and quick disposal of carcasses is essential to halting an outbreak.

Reports of “measled” meat by the Alberta Lamb Producers have increased in recent years. If widespread infection is found in an area, the only option may be to limit grazing in the infectious zone.

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