Quick tick facts

A closeup of a male Rocky Mountain tick (Dermacentor andersoni), a tick species that has been submitted to the WCVM study. Photo: Dr. Shaun Dergousoff.

“Know your enemy” is a well-known military maxim that’s also good advice for people on the Canadian Prairies who are seeing increasing populations of tick species in the region.

Here are some quick facts about ticks and tick-borne diseases:

• Ticks, like spiders and mites, have eight legs in their mature form (as adults) and are members of the class Arachnida. Visit the Centers for Disease Control and Prevention (CDC) web site to view different tick species and their life stages.
• Ticks need a certain amount of moisture to be able to complete their life cycle, so tick sightings are less common in a dry year or in dry areas.
• Ticks in Saskatchewan actively feed in spring, summer and/or fall (depending upon species), and hibernate over the winter months. Winter or moose ticks are an exception: the larvae hang on bushes in long chains in the fall and latch on to any passing large animal such as a deer, moose, horse or cow. The ticks then overwinter on the animal, progressing through their life cycle until they become adults in the spring. At this point, female ticks take a final blood meal before falling off to lay their eggs in the grass over summer.
• Ticks can identify a passing animal through expired breath and body heat, among other things.
• Many species of tick feed on a different animal host at each stage of their life cycle. Studies have shown that certain species of ticks (for example, soft ticks) can survive for many years without a blood meal.
• Ticks that are hosts for the different bacteria causing equine anaplasmosis and Lyme disease lay uninfected eggs. Therefore, in order for an adult tick to infect its hosts, the bacteria must be present in the population of animals that it feeds on as an immature.
• Granulocytic anaplasmosis is caused by tick-borne transmission of the Anaplasma phagocytophilum bacteria. Symptoms for both horses and humans are similar: fever, loss of appetite, mild depression, jaundice and limb edema.
• Anaplasmosis is treated with antibiotics, and if caught early before secondary infections develop, the prognosis for recovery is usually good. Spontaneous recovery is also possible.
• Documented cases of Lyme disease in horses are relatively rare. Both symptoms and test results can be inconclusive. Some studies estimate that less than 10 per cent of horses carrying Borrelia burgdorferi, the disease-causing bacteria, show clinical signs. Lyme disease can be readily treated with antibiotics, especially if caught early. The most common indicator of Lyme disease in humans — a target-shaped rash — isn’t a useful indicator in horses and pets.
• Cases of Lyme disease in humans have been reported in many Canadian provinces and in some tick species of the genus Ixodes. Southern and eastern Ontario, southeastern Manitoba, parts of Nova Scotia and British Columbia have areas where B. burgdorferi are established in ticks (source: Government of Alberta).

Read more about a WCVM-led research study on tick-borne disease in Saskatchewan.