The Agenda with Steve Paikin (Audio) - Tick Talk

Episode Date: September 4, 2024

Blood-sucking ticks are everywhere. With over 9,000 species creeping around the world, which ones should Ontarians be most concerned about? University of Guelph researcher Katie Clow explains.See omnystudio.com/listener for privacy information.

I find a lot of people really don't like ticks. Aside from being fascinating creatures, I think the fact that ticks bite you and they suck your blood for prolonged periods of time can make most people uncomfortable. We tend to fear the unknown and ticks are no exception. Students of the Ontario Veterinary College collect them in order to shed more light on what makes ticks tick. So I'm really motivated in my research to make sure that people know about ticks and use that knowledge to empower themselves to protect themselves against ticks. They are part of a bigger system, they have individual requirements for survival, their habitat, their climate.

And when they come into new areas, they interact with us. And those interactions are really important because ticks can spread things that make people and animals sick. So they really are part of a complex system. And I feel like there's a tick in your hair. That would be funny. My name is Katie Clough. I'm a researcher who focuses on vector borne diseases which are diseases that are transmitted by ticks and mosquitoes and other types of

biting insects. I'm a veterinarian and I'm trained in epidemiology as well. Ticks are parasites. They feed on things that have blood and they rely on that blood for survival. Ticks are also a reflection of many of the large-scale environmental changes that are happening right now. So as we encroach into habitats and change our habitats, we can make areas more or less suitable for ticks. Human-driven climate change is making areas more suitable for ticks, and so we've seen a northward expansion of many tick populations because there are now places that they can survive because the climate has warmed.

So globally, there's over 900 species of ticks, which surprises many people. In Canada, we have about 30 to 40 species of ticks, which again is surprising. But many species of ticks can feed on just a single host, so maybe a certain bird species, and don't really like humans or companion animals, and so we don't see them, and they don't really pose a risk to us. In Ontario there's two to three quite common species that we typically find on ourselves or companion animals. We have the black-legged tick or the deer tick, which is the species that can transmit the bacteria that causes Lyme disease. We have the American dog tick, which right now, other than being sort of a gross, disgusting pest,

doesn't seem to be associated with any high disease risk. So if you're out in wooded, brushy areas, the tick that you're gonna be most concerned about is the black-legged tick or the deer tick. And so we wanna make sure that we're protecting ourselves from encountering that tick and getting bitten. There's no foolproof way of guaranteeing you won't get a tick bite, but there's lots of things that we can do to decrease the likelihood of that happening. You might

have seen pictures of ticks with their arms stretched out waiting for a host, so anything that has blood. And so ticks climb up onto low lying vegetation to do that. And so if we stay on marked trails and out of the really brushy areas, we're less likely to come encounter with ticks that are out there waiting to find us. We can also cover up, so wearing light colored clothing

and making sure that we don't have a lot of exposed skin. The light colored clothing helps us see the ticks easier. They're dark and so on a light surface we can see them quite quickly. We won't feel ticks crawling on us, they're quite stealth that way, so being able to see them is really important. We can also use some bug spray, like Deet has some effectiveness against ticks. It's not completely foolproof, but it does again, help with some repellency. And then when you get home, doing a really good tick check is important.

So checking everywhere on your body, including sort of nooks and crannies, along your hairline, in your underarms, having someone look across your back can be really helpful to see if there's a tick there because the best thing to do is get it before it bites you or get it off really quickly after it bites you for sort of the best protection.

We also need to worry about our companion animals, particularly our dogs, when we're thinking about the black-legged tick, because they can also get Lyme disease. Kevin is my Texan boy. We didn't start in very good terms. He growled at me and my partner for the first two days of his life.

Then we had a family meeting, and then we talked about it, and now we're here. So when we go out and we go for more green space hikes, I like to take my favorite flea comb and comb him around and then just try to see if I feel anything or if the comb itself grabs anything. So again, just a simple, just repetition. There's always gonna be some hair coming out. Look at that fluff and then open it up.

You should come and retry. So ticks like and prefer to be in dark and sort of speak moist places. Checking inside the ear ear, writing here in this area, this corner, this corner. Check sometimes around the teeth in the gum. That one was a little bit gross when that happened. In between the toesies, they like to be on the under pads, like so the back paw, that Kevin does not want to show us right now. pads, like the back part that Kevin does not want to show us right now. And the other fun place would be around the bum area, the groin area, just like back here.

I've been at the clinic for six years now, since 2018, and since then, and in comparison to now, definitely there's been an increase in both tick population and tick transmitted diseases. One of the things that I think it's really been a factor in this, it's not only been the changing weather, but the increase in rescue pests that have come from different countries that come with, sometimes with ticks on them, but most of the times they come with tick transmitted diseases. We have veterinary products that can kill ticks as they feed, and so considering that for your companion animal is really important. They can come into the house with ticks on them.

You want to get them off quickly for their health, and you want to make sure that if they haven't latched onto the dog, when you're snuggling on the couch They don't then crawl onto you inadvertently Ticks have relatively limited movement themselves. They don't jump They don't fly you don't wear games and they just grab a crop Little huggers they can only walk and sort of crawl up vegetation, but the amount that they move is quite limited.

Kinda chillin' there waiting for you, and they have like their little arms up. Usually there's more than one, and they crouch, wait, and they latch on you, and when they grab you, they wait to bite you, and it's gross. We're with little guy, you don't wanna see him. The reason ticks are found all over the place is ticks are

expert hitchhikers. So they have been introduced into many areas because ground dwelling birds can come in contact with ticks. Ticks will climb on them, take a blood meal. And cause ticks feed for four to seven days or more, you can think about a bird flying quite long distances in that amount of time. Tick dating typically happens on hosts. So they meet up on a white-tailed deer, mainly,

which is what the adults prefer to feed on. And the male and female will mate. And then the female stays on the deer for a prolonged period of time because once we mate, she needs a really good blood meal in order to have nutrition to grow her eggs. Ticks can lay thousands of eggs at a time. Fortunately, the survival rate for larvae,

which is the stage that hatches out of the eggs, is not tremendously high, but they are still rather prolific. Although deer are a common place for many black-legged ticks to feed on, and they play an important role in the tick's life cycle because they provide nutrition for the tick, deer don't have a role in the cycle of Lyme disease. And so if they are exposed to Lyme disease, the bacteria that causes Lyme disease when a tick bites,

they have the ability to clear that bacteria from their blood and they won't become infected. If we're thinking about where the tick acquires the bacteria that causes Lyme disease. These are generally small, ground-dwelling mammals like chipmunks, white-footed mice, and some species of shrew. They don't get sick with the bacteria, it just resides in their system,

and when the tick takes a blood meal, the tick is able to become infected. Ticks take one blood meal per life stage, and each blood meal there the tick is able to become infected. Ticks take one blood meal per life stage and each blood meal is an opportunity to pick up a pathogen or transmit it to whatever they're feeding on. When are ticks most active? Adults in spring, fall and warm winters. Nymphs in early summer. Larva in late summer. So if we're talking about the bacteria that causes Lyme disease, there's very little transmission

from the mum tick into the eggs, which then hatch to larva. So most larvae hatch without the bacteria and then they can acquire it if they feed on some small mammal that has the bacteria in their system. They're then going to molt into the next life stage and then take another blood meal. And that's when an individual, if they're susceptible to the bacteria, can become exposed. And so humans, dogs, and horses are the primary ones that we think about when we think about Lyme disease. What are the most common signs of Lyme disease in people? Bulls-eye rash, fever, low energy. What are the most common signs of Lyme disease

in dogs? Lameness, fever, low energy. So ticks have a two-year life cycle which is actually very impressive when we think about a small little creature. Once a population is established, it's very hard to get rid of them, unless you destroy their habitat, which our wild habitats are really valuable and we certainly don't wanna do that.

There are no wide scale pesticides or insecticides that would be safe for every other living creature in the environment and so we would want to avoid doing that. And there are no other known mechanisms that are really good at getting ticks out of the environment. And so a lot of our messaging revolves around once ticks are here they're here to stay. There are many modifications that you can do to make your local area less hospitable to ticks. And so keeping your grass well groomed and short ticks again as I said especially blacklegged ticks have a really high moisture requirement and they're not gonna thrive in that type of environment.

You can also put cedar chips around the edges if you border woods to again break up the environment between sort of the brushy area and your grass so that there's less contact in that regard. When a tick has a blood meal, the blood goes into the tick's gut and that's where the bacteria resides. The next time a tick takes a blood meal,

so after it's developed into the next life stage, the bacteria migrate up through the mid gut of the tick, up into the salivary glands, and then they're ejected into the host. And that takes a period of about 24, at least 24 hours to happen. Ticks resemble spiders a little bit to the naked eye and so some individuals do confuse spiders with ticks which is very understandable. On this sample you can see some important features of ticks.

So we can see that legs here, nymphs, the teenager life stage, and adults have eight legs, so four on each side. This is the mouth part and so there's two palps on each side. They have sort of a sensory role for the tick. And then the actual mouth part is in the middle that it gets injected into the host. And this is the area that fills with blood. So after a tick takes a blood meal, if it's allowed to feed to what we call repletions,

so it finishes and it is full and it's not picked off the host in advance. It can double or triple in size and really just looks like a gray blob. An important feature on the back is this area called the scutum, and we can use both the shape and the patterning of the scutum to help identify the tick. So here you can see that the scutum is round and there's no patterning. And so we also know from other features including the length of the mouth parts and this brownie reddish area that this is a female blacklegged tick. Different tick samples, the length of the mouth parts and their appearance will

differ and as well as the patterning on that scutum. To differentiate this, I'll show you an American dog tick now. Already you can probably see that the size difference is quite notable. So American dog ticks are bigger than black-legged ticks. Black-legged ticks also have longer palps, so this mouth part piece versus here you can see that these are quite blunted on this sample. If you can see there's patterning all over this ticks back. So that's what we call an ornate scutum and that is characteristic of the American dog tick versus the black-legged tick.

Another thing that we can see here is this skewdom covers the whole back versus here, the skewdom only covers half the back. So this is a female and this is a male. If you suspect you've come across a tick, take a photo and submit it to etick.ca. I get a lot of people saying, well now I know about ticks, I'm afraid to go outside, I don't want to be near them.

And that's the last thing that I think I want to have happen. Nature is so important and having a connection to nature is really important. And there's so many added benefits about being outside and so much to learn about so that we're motivated to protect what we have. And so the more you learn about ticks and know how to protect yourself, I think the more empowered people can be to take those actions to protect themselves, their family, their pets, and then go out and enjoy nature and all of the benefits

that it has to offer. The stronger we have a connection with nature we know what we're fighting for and we have a better chance of combating our climate crisis. you