Cattle are at risk of contracting diseases from wildlife and humans are also in danger of being infected, according to a new Alberta study.
Academics from the University of Calgary and the University of Alberta found it’s very common to have wildlife and livestock passing diseases back and forth. It’s an especially vexing problem in southern Alberta, where elk and cattle often mingle in ranch pastures.
Anthrax, bovine tuberculosis, brucellosis and various species of worms are on the long list of illnesses the animals contaminate each other with. Some are zoonotic and can be passed on to people.
The more the animals mix, the higher the threat of the diseases. Monitoring the cattle is one thing, controlling the spread is another.
“You’re not going to get rid of it in the elk,” said Mark Boyce, one of the University of Alberta experts who compiled the study.
“It has certainly led to a risk of infection from wildlife to livestock and some of these organisms are actually zoonosis, meaning that they they can get into humans.”
Research into the overlap of diseases in animals has been going on in the province for years. Much of the work for this new study was done in the foothills south of Calgary. The researchers took data from 16 cattle ranches and tracking information from 168 elk with GPS collars to measure when and where the two species were most likely to cross paths.
The highest risk is in winter months, when the elk retreat from the mountains to sneak a few mouthfuls of hay or a few licks of the salt blocks in the pastures.
The danger stays high into the early spring, as infected elk birth stillborn calves and curious cattle wander over to lick them — that’s all it takes for the cows to contract highly contagious diseases like brucellosis.
Contaminated meat, dairy could infect people
“There is always a concern about wildlife and disease transmission from wildlife to cattle,” Karen Schmid, the research and production manager for Alberta Beef Producers, said. She added the research wasn’t surprising, because illness is something cattle producers are always worried about.
Once a cow is infected, a human can be exposed to the bacteria by drinking unpasteurized milk or eating undercooked meat from a sick animal. It’s “rare” in humans, according to the federal government. It’s easily treated but often requires antibiotics to heal. Symptoms include fever, sweats, weakness and muscle pain.
Canadian cattle have been brucellosis-free since the 1980s, but the elk who originally picked it up from cows decades ago are now potentially reintroducing it to herds in southern Alberta.
Canada has had an average of 10 cases a year for the past decade. In 2010 the U.S. reported 115 cases of the disease. In 2014 there were 354 confirmed brucellosis patients in the European Union. Research has found it’s much more prevalent in developing countries.
The Canadian Food Inspection Agency (CFIA) says people can avoid the disease by staying away from unpasteurized dairy and by careful handling of infected animals and their meat.
If the sickness is found in a herd, the CFIA has control measures including destroying the infected animals, decontaminating the farm and compensating owners for the losses.
“I think it’s important for land owners and cattle producers to be aware of what wildlife frequents their properties,” Schmid said.
One of the authors of the study says lack of manpower on ranches makes that difficult.
“Wildlife tends to avoid people, but there are less people on the landscape and therefore livestock and wildlife freely intermingle,” Marko Musiani, a biologist at the University of Calgary, said.
Watch your cattle
Researchers say moving feeding bales and salt licks closer to buildings will deter the elk from sharing a meal — and more — with the cattle. They added it might be necessary to move livestock closer to farmhouses in the winter and in calving season for easier surveillance.
“Whatever it takes to minimize contact between the two species,” Boyce advised.
Musiani said there’s little the average consumer can do to avoid contracting the illness. The burden to monitor and screen the cattle rests with ranchers and federal government.