Cattle Country: Common ticks and why they can be a problem
The following article was written by Casandra Madden, Danie Wood, and Kateryn Rochon, Department of Entomology, University of Manitoba, for the National Centre for Livestock and the Environment (NCLE). It was originally published in Cattle Country in December 2023
Ticks have always been a fact of life in southern Manitoba, but over the last fifty years, ticks have made their way hundreds of kilometres north of where they were usually found. Ticks can pose a threat to people and animals as they must feed on blood to develop, and they can transmit bacteria or viruses while doing so.
Ticks in Manitoba
The two most common ticks in Manitoba are American dog ticks (also known as wood ticks) and blacklegged ticks (also known as deer ticks). American dog ticks can transmit bovine anaplasmosis in cattle and bison by feeding on an infected animal and then moving to an uninfected animal and feeding on it. Because the bacteria that causes bovine anaplasmosis is in the blood, it can also be transmitted between animals by horse fly bites and by using blood-contaminated equipment without cleaning between animals. Blacklegged ticks are a more recent addition to the Manitoba fauna, and they can transmit pathogens that cause Lyme disease, human granulocytic anaplasmosis, and babesiosis, which can affect humans and horses.
Adult American dog ticks are out looking for blood starting in May, peaking in June, but will be active until the end of summer. They like more open spaces with grasses and shrubs and more space between the trees where the sun can shine through. Blacklegged ticks, on the other hand, dry out more quickly and are typically found in areas with dense vegetation and higher humidity, forested areas with more leaf litter and less sun. Adult ticks will be looking for hosts to feed on as soon as the snow melts in April through May and into June. However, that is not the end of them! In June, we also see young blacklegged ticks, called nymphs, looking for blood. These immature ticks, about the size of a poppy seed can transmit bacteria and parasites just like the adults do. Then, a new generation of adults come out to feed in the fall, starting in late September, through October until there is snow on the ground. The adult ticks that do not find a host in the fall overwinter in leaf litter under the snow and are the ones that come out to try again once the snow melts. Understanding the risk these ticks can pose to cattle, horses, and humans may lead to prioritization of tick management strategies.
Ticks and your pasture
To reduce the chances of tick bites, we need to know where the ticks are more likely to be and when they are more likely to be there. We know ticks tend to prefer certain habitats that make it easier for them to survive and find hosts to feed on, and pastures can offer some of these preferred habitats. That means there is a greater risk of exposure to ticks for animals grazing in those pastures, and to people working with those animals. University of Manitoba graduate students Casandra Madden and Danie Wood are looking at ticks on pastures more closely and are trying to identify what features could increase the risk of tick bites on a pasture. Their preliminary results seem to indicate that pastures that are less managed and have diverse vegetation provide ample grounds for small mammals that immature ticks can feed on. Areas
where vegetation grows a bit longer, including sections with more trees, fence lines, or the edges of well-travelled paths and sloughs, all provide higher humidity that the ticks need to survive. It is in these areas where ticks can climb on to get on larger hosts like cattle, horses, and people.
How to manage ticks on your farm
It is not practical to apply “backyard” tick management practices like mowing the lawn, removing ground cover plants, or aiming for the complete exclusion of wild hosts (deer, rodents, birds) from grazing pastures. However, by knowing when and where there is more tick activity, we can target those areas more effectively, try to reduce interactions with ticks, and check for them. To start, clean up dead plant material such as leaf litter and reduce long vegetation around troughs, watering holes, or other structures cattle and horses visit frequently. Keep the dead plant material in direct sunlight and allow the ground to dry out. This lack of humidity will reduce the number of ticks that survive and the area will be less attractive to small mammals. If possible, keep the vegetation low at the edges of paths well-traveled by livestock – and producers. When planning out grazing, consider keeping animals away from treed areas until peak tick activity has passed. Managing where the cattle and horses graze can reduce the contact between ticks and their potential hosts. And let’s not forget to check ourselves for ticks! While American dog ticks are mostly just annoying for us, blacklegged ticks can transmit infections to humans, and can severely affect the well-being of the farm. While working on and around pastures, moving animals or fixing fences, protection and awareness are key. Wearing light colour clothing helps spot ticks crawling up. Fully tucking shirts into pants and pants into socks will keep ticks on top of the clothes and away from the skin. In addition, wearing a repellent containing DEET, icaridin or picaridin will keep ticks away.
Learn more about the ticks you find
What if you find a tick and you are unsure what it is? Take a few pictures and submit them to eTick. eTick is a Canada-wide public platform for image-based tick identification. Users can submit a picture of a tick through the website (www.etick.ca) or the eTick phone app and get an identification within 24 hours, along with any relevant tick-borne disease information. You can download eTick from the QR code below. There may be snow on the ground, but the ticks are there, waiting for spring and their next meal. Keep them in mind and be ready.
What’s next?
The University of Manitoba Veterinary Entomology lab continues to work on bovine anaplasmosis in ticks and horse flies. We are looking for volunteers to participate in our new research project funded by the Beef Cattle Research Council. We are looking for producers who will let us take ticks, flies, and cattle blood samples, and participate in an online survey to document husbandry practices. Our goal is to use the blood samples to develop a simple test that can detect infected animals quickly and get a better grasp on the risk factors for bovine anaplasmosis, including where anaplasmosis occurs and what management practices increase or reduce the risk of transmission. To get more information on how you can help fight the spread of bovine anaplasmosis, contact Dr. Shaun Dergousoff (Agriculture and Agri-Food Canada – Lethbridge shaun [dot] dergousoff [at] agr [dot] gc [dot] ca) or Dr. Kateryn Rochon (University of Manitoba kateryn [dot] rochon [at] umanitoba [dot] ca).