It’s a common practice at Alberta ranches in the fall to treat cattle
brought in off pasture for parasite control.
But as cattle prices slide, producers might want to ask whether it is
necessary to deworm their herds every year. It’s a question posed by
Alberta’s chief provincial veterinarian.
“I’m not telling people not to do it,” said Gerald Ollis, “but I’m
questioning it myself.”
Parasites of concern are roundworms that can live in the gut and
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intestines and lungworms, which can infest the lungs. Both can hinder
the weight gains and feed conversion of calves on pasture.
In Alberta, where pasture conditions generally are drier than in a
province like Manitoba, it can be harder for parasites to flourish.
They thrive better in moist conditions, where they can comfortably
multiply before being eaten by grazing livestock.
Mark MacNaughton, an Alberta forage and beef specialist, agrees with
Ollis that deworming may not be needed every year in every area of
Alberta.
“It’s expensive,” he said. “It’s not like throwing a dollar ear tag in
the cattle.”
However, like Ollis, MacNaughton is not suggesting that producers
abandon deworming as part of their herd health regimen.
For producers with closed herds and pasture conditions less inviting to
parasites, there might be an opportunity to skip the odd year of
treatment, he said, especially those that have had a sound program for
controlling parasites in place for several years.
He also suggested that producers would want to make sure any new
additions are treated to limit the risk of them spreading internal
parasites to other cattle, “because you really don’t know the history
of those animals.”
As well, there might be times when it is worth it to deworm a herd more
than once a year.
Lyall Petrie, a professor of large animal medicine at the Western
College of Veterinary Medicine in Saskatoon, said in many areas of
Alberta and Saskatchewan where the weather generally has been dry, one
treatment a year should suffice.
However, where conditions are typically moist, such as Alberta’s Peace
region, it might be worthwhile deworming in late July as an added
precaution, he said.