Manitoba's mild weather a recipe for uptick in ticks

Manitoba could be facing an uptick in ticks and mosquitoes this spring, with milder weather so far this year contributing to a longer bug season.

The climate is generally getting milder, which means more unpredictability when it comes to summer pests, said Bryan Cassone, a professor who chairs the biology department at Brandon University. 

"Milder climate is always a good recipe for different insects to become more abundant and expand their range," he said.

"All the forecasts suggest that we're going to have a lot more infectious diseases that are transmitted by mosquitoes, ticks and other bugs."

As spring starts, there are two main ticks to worry about, said Cassone. The more abundant is the American dog tick, also known as the wood tick, which becomes more active as the days get longer.

The other is the blacklegged, or deer, tick, which becomes active when temperatures hit around 4 C, he said. 

"It doesn't matter if it's the winter, it doesn't matter if it's the spring — that's generally when they start coming out," Cassone said. 

Some deer ticks do die off with extreme cold, but it's a negligible amount, Cassone said.

Blacklegged ticks also present a concern because they can spread Lyme disease. A recent Canadian study also found that ticks infected with Lyme disease tend to survive better over winter and live longer. 

Lyme disease is particularly a concern when ticks are in their nymph, or larval, stage, Cassone said, because the larvae are smaller and harder to spot.

As their season expands, "we have more … ticks active and we have more nymphs active, so we have a greater risk of Lyme disease," Cassone said.

Heartworm season coming earlier

The odd weather the province has seen recently, with a warm winter and recent swings between melting and freezing, has veterinarians prepping for an earlier season for ticks and heartworm — which is transmitted by mosquitoes — says Grant Park Animal Hospital vet Jonas Watson.

He says they are starting to see ticks as early as March, and worries some may even have been active on warmer days in late February.

"As our climate changes, we're going to be seeing more and more of these ectoparasites showing up earlier and earlier in the spring with each passing year," he said.

"April is looking like we're going to have warm days," he said. "We should be thinking about ticks a little earlier."

Mosquito populations depend on the spring's moisture and temperature levels, Cassone said. If temperatures stay on their current track, Manitobans will likely start seeing the pests in around four weeks.

"You're going to start seeing mosquitoes probably a little bit earlier this year," Cassone said. "But they're not going to be, in most cases, the ones that are going to be [a concern] for infectious diseases."

While there are mosquitoes carrying heartworm in the population, vets and pet owners are helping limit the spread by using medication, Watson said. 

But heartworms are also showing up earlier in Manitoba. In the past, heartworm season typically ranged from June to November, but it's getting longer, Watson said.

"We're sending home as many as eight months worth of heartworm medication at this time of year, and trying to keep dogs protected from March, April all the way to November," he said.

A concern for farmers

Birtle cattle farmer Tyler Fulton, who is second vice-president with Manitoba Beef Producers and vice-president of the Canadian Cattle Association, says he's on the lookout for ticks and other pests.

But "it's too early to really kind of get concerned about that in a big way," Fulton said.

However, the mild weather could lead to a possible increase in weevils affecting alfalfa crops. It's also made it harder to anticipate which bugs to worry about, and when, said Fulton.

Variable weather is a concern for agricultural producers, he said.

"And it's that kind of variability that's going to ... lead to, you know, more weird events happening and having to deal with infestations, or just different kinds of production-related challenges."