Battling a New Eight-legged Foe with Olds and Tarpoff | Part One

Flies and ticks are certainly getting their time in the spotlight, aren’t they? Whether you’re following the daily newsbytes related to New World screwworm’s march north or the recent announcements regarding Lyme disease or Alpha-gal syndrome, insect-focused news is everywhere. One critter getting a little less attention outside agricultural journalism? The Asian longhorned tick. 

On this episode of Angus at Work, we welcome you to listen in as we visit with Kansas State University’s Cassandra Olds, assistant professor of veterinary entomology, and A.J. Tarpoff, associate professor and beef extension veterinarian, regarding this eight-legged foe and the protozoan parasite it carries known as Theileria orientalis.

Additional Resources:

• Asian longhorned tick | USDA APHIS
• Story map | USDA APHIS
• Bovine Theileriosis | USDA APHIS
• Subscribe to the Angus Beef Bulletin EXTRA

Thank you to Superior Livestock Auctions for their sponsorship of this episode.

Find more information to make Angus work for you in the Angus Beef Bulletin and ABB EXTRA. Make sure you're subscribed! Sign up here to the print Angus Beef Bulletin and the digital Angus Beef Bulletin EXTRA. Have questions or comments? We'd love to hear from you! Contact our team at abbeditorial@angus.org. 

Transcript

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Host Lynsey McAnally (00:19):
Angus at Work, a podcast for the profit-minded cattleman. Brought to you by the Angus Beef Bulletin, we have news and information on health, nutrition, marketing, genetics and management. So let’s get to work, shall we?

Flies and ticks are certainly getting their time in the spotlight, aren’t they? Whether you’re following the daily newsbytes related to New World screwworm’s march north or the recent announcements regarding Lyme disease or Alpha-gal syndrome, insect-focused news is everywhere. One critter getting a little less attention outside agricultural journalism? The Asian longhorned tick.

On this episode of Angus at Work, we welcome you to listen in as we visit with Kansas State University’s Cassandra Olds, assistant professor of veterinary entomology, and A.J. Tarpoff, associate professor and beef Extension veterinarian, regarding this eight-legged foe and the protozoan parasite it carries known as Theileria orientalis.

But first, we want to take a moment to thank Superior Livestock Auctions for their sponsorship of this episode.

Superior Livestock ad (01:48):
Superior Livestock Auction is the largest cattle marketing network in North America. Our leadership makes a difference and our customers get top dollar.

"Superior has traditionally been the best price for us rather than taking them to the sale barn. It's a pretty big deal to have multiple buyers bidding on your cattle all over the country, too".

Go online or call Superior Livestock Auctions to learn how selling your cattle the Superior way can work for your operation.

Host Lynsey McAnally (01:49):
Welcome to Angus at Work! I'm your host, Lynsey McAnally, and today we're learning about the Asian longhorned tick from two people who have devoted a good bit of time to researching the insect itself as well as the challenges it could pose to cattle producers. To kick us off, I want to learn a little bit more about both of you. So, Cassandra, do you mind telling us a bit about yourself?

Cassandra Olds (02:11):
Yeah. So I'm Cassandra Olds. I'm a livestock entomologist, which means that I deal with anything with six or eight legs that impact our four-legged bovid. That's both their impact on production, just the insect itself, but also the pathogens that they transmit. So Theilerias, anaplasmas, babesioses, the whole nine yards.

Host Lynsey McAnally (02:33):
Awesome. And do you mind telling us where did you grow up? And what is your background?

Cassandra Olds (02:39):
Yeah, so I am from sunny South Africa. That's where I came from originally. I actually did my PhD in Kenya and Switzerland, which was a really neat experience. I worked on the African cousin of Theileria orientalis, which is Theileria parva, which is way worse. Way worse. I came to the U.S. because of Theileria. Then I spent a little while where I didn't work on Theileria and I started working on flies and things like that. Now my career has come full circle! I'm back on Theilerias and I'm excited about it because I find it fascinating, but I'm also sad that we have to be here.

Host Lynsey McAnally (03:19):
I understand. Thank you so much for joining us. I know there are so many topics out there that have to do with insects at the moment of various numbers of legs. I appreciate you being here to maybe put some of those concerns at ease. A.J., it's your turn. Tell us a litle bit about yourself.

A.J. Tarpoff (03:40):
Yeah. A.J. Tarpoff. I'm the beef extension veterinarian at Kansas State University. My background is all about cattle. I came from a beef background, went through veterinary school and my graduate degree. Went into feedlot practice. I came from the feedlot world. Came back to K-State where now I have an opportunity within this role to really serve all aspects of beef cattle production, from our cow-calf operators, our growers and backgrounders, our feeders, get to work closely with our veterinarians within the state and nationwide. And then, ultimately, I get to interact with our consumers and to be able to explain and discuss cattle production. What we do to be able to create beef? So that's a little bit of my background and what I'm doing today.

Host Lynsey McAnally (04:26):
Between the two of you, we're going to be in a very good situation to talk about exactly what this Asian longhorned tick is and the effect that it's having or could have on the industry as a whole moving forward, which I know has been a really popular topic amongst ag media of late. So I guess - getting back to basics - Dr. Olds, would you mind telling us what exactly is the Asian longhorned tick?

Cassandra Olds (04:51):
Yeah, so it's a really fascinating tick. I mean, I think I'm one of the few people in the world who get excited and fascinated by ticks, but here we are. It's an invasive tick. It's not a native U.S. tick species, but it's very successful and it's invaded multiple places globally. The U.S. isn't the only place that has had this issue. It's fairly unique. Where other tick species, you have to get an adult male and an adult female tick on the same animal - which is actually harder than you would think because once an adult female cements herself in, she can't go anywhere. She really relies on the chance interaction of the animal that the tick is on passing by a male tick of the same species, that male tick attaching on and then being able to find her. She cemented in there, which is crazy.

I mean, the odds are super, super low. So this is why even though tick populations will fluctuate year to year, they remain largely stable. However, this tick - the Asian longhorned tick - doesn't need to mate to reproduce. It's a clonal tick population. Almost all the ticks are female. Occasionally, every now and then, you'll find the odd male, but they're almost defunct. They don't feed, they don't mate, they don't do anything. It's just a weird tick freak thing. And so you have a tick that doesn't need to mate to reproduce. All you really need is a very small number of ticks to be introduced into an area for a full-blown infestation to establish. They are unique and this is why it's traveled as quickly as it has and how its infested as many places as it has.

It's also a very general feeder. It'll happily feed on anything that comes across. Some of our other tick species are a lot more selective. And so, again, they don't care if it's a rabbit or a bunny or a squirrel or a mouse or a bird. Or a human. It just is the epitome of success in tick terms. This is why it's become such a problem.

A.J. Tarpoff (07:03):
A little bit of background. Within the United States, it was first recognized that it was even here back - we estimated - at least 2017. In reality, much further back. Started on the East Coast. New Jersey, Virginia, some of those locations and since then has traveled from the far East Coast and gone from animal to animal to animal and has now reached Kansas. As far west as Kansas.

Cassandra Olds (07:30):
Which is crazy if you think how small a tick is and that they don't inherently move. Grossness aside, nobody really likes ticks, but you've got to be fascinated with just what it has accomplished.

A.J. Tarpoff (07:46):
The spread. Even though it's from 2017 to 2026, or within the last decade moving state to state to state, that means that those ticks have gone from animal to animal to animal to animal and been transferred because they don't move by themselves. They had to be transferred all the way out. Now, I had a conversation with a veterinarian not long ago and we were talking about this tick and I finally put the pieces together that another way to explain it of how this tick can really thrive is infectious dose or the idea of an infectious dose. That if there's a really small amount that it gets into a new area or a new population, it can cause an issue and really thrive. Well, in this circumstance, as little as one tick potentially can reintroduce or introduce it to an entire population over just a couple of years. And before we know it ... We may have had some of the immature stages, but before we know we have an entire infested pasture that is inundating our cattle herds or inundating our farm dogs or our sheep or whatever species you might have out there.

So it's a really interesting tick on not only its life cycle, but its ability to spread and spread quickly.

Cassandra Olds (09:03):
Yeah. And to follow up on that, it goes unnoticed for a long time because look, this tick doesn't have a painted orange back on it or a little check mark like, "Hey, this is what it is ... " When you look at the tick, it's a nondescript brown tick. We have nondescript brown ticks. It's not different in size, it's not different in shape. To do an identification, you have to put it under a microscope. And so if somebody sees a brown tick on themselves, they're not like, "Oh, here's this invasive tick." You're just like, "Oh, here's a brown tick, like the other brown ticks that I see." And so it goes unnoticed for a long time. It's only when you get these hyperinfestations that you're like, "Oh wait, this is abnormal. This is way worse than what it normally is." And that's when people are like, "Whoa, something might be wrong here."

A.J. Tarpoff (09:53):
Is the proper way to say that ... Is it a swarm of ticks?

Cassandra Olds (09:59):
It's not really a swarm. Ticks are really interesting in that we'll also sometimes call it a tick nest and that's not entirely accurate. So what happens is - and why this happens is - a female tick will take up as much blood as she can and then she'll stop secreting all the anti-inflammatory. The host's immune response kicks in and then [the tick] gets ejected out like a splinter. If you've ever seen a really big fat tick, like first of all, arms are out there doing nothing. So the host actually ejects it out and they often will land where an animal was lying. And so if you have a few of those fall off, realistically they can't move very far because they've got these tiny little legs sticking out on the side. So she will lay her eggs very close to where she's fallen off. If you have a few of those laying eggs in that same area, then you've got thousands of larva that come out in the same area and they don't spread out.

They just stay where they are and wait for something to find them. It's not that the ticks are swarming or gathering in an area, it's more that the animals are in that area. They happen to fall off, they happen to lay their eggs right where they were and then somebody else happens to move into that area. Ticks themselves are not ... they don't move. They are where an animal is and then hope that somebody else comes along their way.

A.J. Tarpoff (11:29):
Yeah. I'm glad you brought that up, Cassandra, because ticks ... they're not equally distributed across the landscape. We find those populations, we find key areas and I'm sure folks listening in, they all know that if they walk over to some location of their property, they're going to pick up ticks on themselves, let alone their animals. So whether it's a hotspot for animal behavior, it has the proper brush and the proper environment. That's kind of where these ticks really thrive similar to our native species.

Cassandra Olds (12:00):
Exactly as you said, A.J., it's that interplay between areas that animals frequently inhabit, but also areas that are suitable to a tick surviving. A tick actually spends most of its time not on an animal and it's at risk of drying out, it's at risk of heating, it's at risk of being frozen. So when you get these thickets of high humidity, ticks tend to survive there. It's not that they aren't dropping off in other places, it's just that where we tend to see these hotspots, it's areas where animals frequently visit but also is suitable to tick survival.

A.J. Tarpoff (12:39):
And, Cassandra, can you explain a little bit about, you can explain it better than I can, but the multiple hosts necessary for the entire life cycle. So if we take an Asian longhorned tick, it begins with an egg. We have the adult female, it lays that egg, but then we have to have a blood meal to be able to carry out the life cycle, which can take a couple years, correct?

Cassandra Olds (13:00):
It can take a couple of years. So no matter when we are talking about our hard ticks and the soft ticks - the bad ticks that we commonly know - that's a whole different group. When we're talking about this right now, we're talking about hard ticks. [Those] are our common ticks that we usually get that we see on our livestock and our pets and ourselves. No matter which species you are, you have an egg stage, you have a larval stage, you have a nymphal stage and you have an adult stage. So three blood feeding stages. Now the Asian longhorned tick is what we call a three-host tick. [That] means the larval stage feeds on one animal, it falls off, it molts, it has to find animal number two for the nymphal stage. It feeds, it falls off, it molts and then it's got to find its last stage being the adult.

And the time period between this can vary. After they've molted, they actually need a little bit of time to firm up that exoskeleton again. But, theoretically under great conditions, you could go through that entire life cycle in a couple of months. However, we don't have great conditions year round. We have winter, we have summer and so they'll actually time that. They can detect the temperature, they can detect ambient light conditions and they'll say, "Okay, we're getting into fall now. I'm probably not going to find another host. I'm going to spend the winter hanging out safe in the leaf litter and the brush. Protected. I'll try again in the spring." We can have this over the course of two years at least. The fact that the Asian longhorned tick will feed on anything really means that it is very successful in its environment, but we have to have a different host at each stage.

Now that host could be cattle all through, but it could also be a squirrel, a rabbit, a dog ... This is important and we'll chat about Theileria later, but the acquisition of the pathogen, the tick has to get the pathogen. It has to be infected during one of those stages and then it only transmits it during the next stage. So, for example, a larva will acquire it from an infected animal. It has to feed 'til it's finished. It's got to molt, it's got to then find another cow to transmit it. It's a complex process, the biological transmission of it.

Host Lynsey McAnally (15:34):
I feel like every time I have the opportunity to chat with someone in entomology, it always comes back to you may be grossed out by these little critters, but you also have to think it's almost a miracle for them to be able to proliferate.

Cassandra Olds (15:49):
Well, okay, you said it. So here's something that is absolutely unrelated, but I'm going to say it anyway because you brought it up. I'm a microbiologist by training. I'm a microbiologist. I started off in the lab with pipettes and DNAs and all these things. I started on the disease aspect of it and I loved the disease aspect of it. When I was doing my Masters, my advisor at the time said, "Well, if you're working on tick-borne pathogens, you've got to understand ticks." I was so grossed out. Nobody wants to be ... I mean, come on. I was like, "Fine." As I started learning about them, I remember the first thing that blew my mind is when I learned that there's certain tick species that can extract water from air. They take their saliva and they push it out into their mouthparts and then - because of the difference and the high amount of moisture in the saliva - the water basically comes out of the vapor, condenses on the saliva and then they suck it back in.

I was like, "Oh my goodness, this is crazy stuff." And then as I started learning more about not just ticks and then there's flies and then there's all these things, I'm like, "This is crazy. This is fascinating." Now I very rarely set foot in a wet lab where I'm doing wet lab stuff. Everything is just about these organisms because they're fascinating and they're so small, but their impact is so huge. That's my fun fact segue.

Host Lynsey McAnally (17:26):
No, I love that. Just learning about them, the amount of modifications that they've had to go through to get to where they're at and how they adapt to their environment and adapt to all these conditions. And it's very easy to be like, "Well, we can do X, Y, Z and get rid of them." But it's almost as though they've learned around us already. Adapted around us. Evolved around us already. And so that's another whole conversation of how do you combat both ticks and again, Theileria, which we'll talk about in a minute. The people that are on that side of things, having to do that research, it's got to be mental gymnastics from my point of view to learn and get to that point.

A.J. Tarpoff (18:14):
I think that's an excellent point. These are parasites, whether it's a tick, whether it's an internal roundworm, whether it's a tapeworm, these are parasites that, one, if we're going to control the impacts of that parasite or what it carries, we have to be able to control the disease. We have to control the parasite that is out in the environment interacting and is mobile to be able to ensure the health and wellbeing of our animals. And these parasites, no matter what parasite, whether it's a fly, whether it's a tick, whether it's an internal parasite, they have singled out all of the different species that they feed on. They can evade host defense mechanisms, survive and thrive at basically the downturn of whatever they're feeding on. So it's not a good relationship, but that's how their entire life cycle has been made. For millennia.

Cassandra Olds (19:14):
For millennia. I mean, you look at ticks in amber and it looks like a tick today. They reached peak evolutionary performance. They were like feeding on dinosaurs and they're like, "Cool, we got it." And they still look the same. Dinosaurs have come and gone. Ticks are still mucking around.

A.J. Tarpoff (19:31):
Ticks and mosquitoes.

Cassandra Olds (19:32):
A mosquito is one of them.

A.J. Tarpoff (19:34):
It's the guarantees in life: death, taxes and external parasites.

Host Lynsey McAnally (19:43):
My brain just had a moment because, I guess, you think about how long they've been around, but putting it into words ... Quantifying it. That's crazy.

Cassandra Olds (19:56):
Yeah. And then we are like, as little measly humans, we're going to outsmart them? Yeah, sure.

Host Lynsey McAnally (20:02):
Well, hopefully we get to the bottom of that during this conversation. So jumping off into another question ... I mean all of that. That alone is educational for me, but what are the concerns with the continued spread of this pest? I know we're going to talk about one part of that here in a little bit, but it's not just the infestation issue that they can cause from a feeding perspective, but also disease concerns. From both of your perspectives, what would you say is the major thing that producers need to keep in mind?

A.J. Tarpoff (20:39):
I guess I'll start. From a production aspect, any and all ticks, they are robbing from the host and giving nothing back. They are drinking blood. They are taking away from the host. That means that host has to build an immune response, use resources, which is energy and protein and everything else. So it's taking away from the ultimate purpose of growing an animal, going through gestation, producing a pound of beef. So we do have the performance losses that's been documented with numerous different tick species. Yes, we can just have the loss because - in some circumstances - we can get anemia and we'll get into that where there's so much blood loss that it can be a threat to that animal's life. But, yes, there's the performance side. Then what about other things. Animal wellbeing, yes, they inject a certain chemical that makes sure that the host doesn't know that they're attached.

That's great, but it's still damaging the hide. They start to get itchy, they rub up against things. So we're taking away value within the beef industry from hide damage, loss of performance, loss of animal wellbeing, because there's always a continuous threat and an inundation to those animals. As a veterinarian, I look at it as a wellbeing and a welfare concern whenever we have some of these really extreme scenarios with a ton of ticks. So that's where I frame it around in my mind.

Cassandra Olds (22:13):
There is the direct damage to the animal, but then there's the indirect damage through the transmission of these pathogens. That's where people's focus tends to go and then we forget about the direct damage that AJ just mentioned. The tick alone is an issue.

Host Lynsey McAnally (22:35):
For those listeners that may not be aware, the Asian longhorned tick carries the parasite Theileria orientalis. So for those listeners, what would be your elevator speech be to explain Theileria.

Cassandra Olds (22:48):
Okay, A.J., I'll do the elevator pitch. So this is a protozoan parasite and this is important to say right off the bat because it means that antibiotics aren't going to work and we don't have a vaccine. This is a protozoan parasite that we do not have a treatment method for. It replicates in red blood cells and it can cause a wide range of issues going from absolutely no issues at all to pretty high death loss. This is where the complexity comes in. Where on the spectrum are we going to be? It's important to know that once animals are infected, they're infected for life and that they can have relapse of disease. Then I would say the other thing that we really need to keep in our minds as we frame this as a tick-borne pathogen, but it is not just a tick-borne pathogen.

You can never have the Asian longhorned tick and you can have a whole lot of problems with Theileriosis because we, number one, have the relapse. So you can bring in infected animals, not know that they're infected and you could have severe disease relapse. But, importantly, it can be transmitted mechanically. We've talked about the tick and its biological transmission. That means that tick can take in a small amount and amplify it. We also have mechanical transmission. I always use the example of you carrying your groceries from the trunk of your car to your kitchen. However much I wish that when I pick up that bag from the trunk of my car, there's miraculously going to be more groceries. When I put it off in my kitchen, there never is. I'm just moving it from one place to the other. So we have mechanical transmission through blood sucking lice. We have needle transmission. We probably have transmission through biting flies and then there is a small level of transplacental transmission. So people just need to keep in mind that this is more than just a tick-borne pathogen. Did I miss anything in my elevator pitch? Did I get off on floor three instead of floor five?

A.J. Tarpoff (24:58):
Well, it depends on how big the building is.

Cassandra Olds (25:00):
 Yeah, there you go. There you go.

A.J. Tarpoff (25:04):
I was asked recently, it's like, "Okay, just give it to me straight, Doc, what's Theileria? Why do I care?" And I'm like, okay, blood-borne pathogen destroys red blood cells during its replication can cause anemia and death or you have a lifelong infection that could ... Usually it doesn't get sick anymore. If it survives after the initial exposure, if it survives, [there is a] high likelihood it's never going to have an issue again. Unless we have very severe stress on that animal, then you can see problems later on. So it's one of those things. We have other diseases that are similar in some aspects, but in a lot of other things this is a brand new challenge that we really haven't been able to ... We don't have perfect answers for. It spreads very differently than other diseases we're used to. It's not as simple as, "Oh, you have a bacterial infection, you get this antibiotic and we're going to be fine." We don't have some of those cures.

We don't have some of those ultimate control measures. It's a little bit different and it's a new challenge that our industry is going to battle and hopefully overcome.

Cassandra Olds (26:21):
Yeah. And one thing I'll add to that is that it's changing. We're learning new things all the time. I mean, if I even think about what we thought we knew a year ago versus what we see now, and I think that's really important for people to keep in mind, listen to these talks again and again and again, because I'm telling you now ... In six months, we're going to have learned new things. Keeping up to date with all the new things that are coming out, we're learning as we're going along, we're figuring it out, we're putting the pieces of the puzzle together, which is great. It also means it's a rapidly changing situation. So keeping up to date with the latest information is good.

A.J. Tarpoff (27:04):
Kansas is a unique area. We're a net importer of animals from all over the country. Now when we have quote-unquote "endemic locations" from the East Coast throughout middle and eastern America. I mean, we're importing animals over the last decade that have been positive for Theileria. Well, if we've been importing animals to Kansas that have been positive, have we been seeing massive outbreaks within the state of Kansas? Well, no, we haven't. Have we had issues? Have we had positives? Yes, of course we have because we're importing positive animals almost every day, but that's where what we're seeing today is very different than outbreaks in the past. It's not like the outbreaks that happened in Australia and New Zealand and some of those locations. It's not like what originally was occurring in Virginia early in these courses. What we're seeing today, we've kind of trickled in some of this Theileria over the last decade and just now has that biologic vector of the Asian longhorned tick has caught up with the spread of the disease.

This is a new frontier. We have a host herd within Kansas that has probably been exposed over the last decade, but it's the young calves that we're continuously bringing in as feeders and backgrounders and going into the feedlot that the stress of transportation and the stress of marketing is causing some unforeseen problems that we really didn't anticipate.

Cassandra Olds (28:39):
And that we didn't see in other states because that's not how they produce their beef, right? They send their beef to us. So I think that sometimes it's fascinating how these things evolve and how it changes over time just based on where it impacts next and what that production system looks like.

A.J. Tarpoff (28:59):
So I guess Theileria, what somebody would see, if I'm a producer, I'm bringing in animals or I just have a home herd. What is Theileria? What does it matter for me or what should I keep my eyes on is it may look like very similar in some of our mature animals. It may look very similar to something called anaplasmosis, which is a bacterial infection that it actually gets into the blood and the red blood cells and causes anemia. So we can see anemia with Theileria, but [anaplasmosis] usually impacts older animals, older, naive cows and bulls within those areas. With Theileria, we can see it equally almost in, if they're all naive, we can see it in older animals or younger animals. So it's an equal opportunity employer from that perspective. We can see the traditional jaundice. We can see white mucus membranes. We can see extreme lethargy. Just overall not doing well.

If the animal dies, we will see some things typical of anemia. We can see in an enlarged spleen. We can see either the yellowing or very pale fat, one or the other, depending on how long it's been going on. Or we can have some things in feeder cattle where we have immune disruption and we have animals that are just [unresponsive]. They're [unresponsive]. We think it looks like Bovine Respiratory Disease [(BRD)] or pneumonia and we treat them accordingly and then all of a sudden we realize, "Boy, our treatment success is so far out of whack from what we were expecting that we have [unresponsive] animals." It's a different thing to think about that it's something out of the ordinary. That's what I keep harping on with producers and veterinarians: When you see something abnormal that should ring a bell. Either it's, "Boy, ticks are really bad this year and my animals are inundated with 10,000 ticks." That should send up a red flag.

Why are all these ticks here all of a sudden? Is this the same thing I've always been battling? And then on the feeder side, keeping documentation. Making sure that we're tracking animal health, morbidity and mortality. Sickness and death loss. If our treatment success just goes downhill and the necropsy results of some of those animals that succumb to illness don't match what the clinical signs were, those should all be red flags that, "Hey, maybe something else is going on here."

Cassandra Olds (31:34):
And to what AJ mentioned - anaplasmosis- we do have cattle that are coinfected with both anaplasma and Theileria. I think sometimes people have been thinking that they've got anaplasma issues and again, it's not responding to treatment. If you haven't historically had issues with anaplasmosis and then all of a sudden you think, "Oh, I've got a lot of anaplasmosis." It may not be anaplasmosis, it may be Theileriosis. We're doing research now that's looking at, okay, if you're infected with both, what do you do? This is a thing that we need to look at. The animal exists in its environment and it may be coinfected with both these things. They have very similar disease progression. There are differences, but these are both diseases that do have some similarities, one of them being anemia. So how do these interact with each other? We just don't know yet.

A.J. Tarpoff (32:28):
I do want to point out this is not a human disease. Theileria orientalis is not a human disease. This is a cattle-specific disease. So for producers listening in, anybody listening in, this is not a human health issue. This is not a food safety issue. The beef, everything. We have no concerns there, but we can see some issues with production and morbidity. I guess that's one thing to always consider. The other consideration is just because an animal was exposed doesn't mean it's a death sentence. In the vast majority of circumstances, infections go unnoticed. So by the time that we've realized we have Theileria going through a group of animals, essentially everybody's already been exposed, but maybe only a very small percentage had any issues. So it's not an immediate death sentence. This goes through groups. By the time we realize what the issue is, it's probably spread through massive amounts of animals before we realize what happens.

So just because an animal's positive doesn't necessarily mean, it's not a death sentence, but it gives us an indication of what might be happening on a bigger scale.

Cassandra Olds (33:43):
I can't tell you how many people I've spoken to who, once we get the herd tested, they're like, "But this can't be right. I never had any disease." The rule is that it comes in without any incidents. It's the exception where we start seeing clinical disease. It's just those are the ones everybody talks about. Nobody talks about the herd that never had any disease because we didn't know it was there. So there's the skewed perception of how bad it can be sometimes.

A.J. Tarpoff (34:11):
But even going back to originally finding some of these issues, I'll take Virginia as an example. It was going through Virginia, they were having cow-calf herds that were having problems and I was discussing this in one of my classes. I had a student come up to me afterwards and said, "Hey, Doc, my family's herd was one of the sentinel herds in Virginia." I said, "You've got to be kidding me. So you're well versed in Asian longhorned tick and Theileria." He said, "Absolutely." I asked him, "What was the outcome?" He goes, "Well, by the time they figured out that it was Theileria, we blood tested the entire herd. Everybody was positive. We stopped having problems." It's almost consistent that we see that a lot with Theileria.

Cassandra Olds (34:56):
And encouraging. I always say this to people that everybody's gut reaction is, "I'll keep it out at all costs and if I have positive animals, I'm going to get rid of them no matter how good they are. " I think we've got to think about this in the long run. We are never getting rid of Theileria. We are never getting rid of Asian longhorned tick. If we can get herds stable as soon as possible, there is a way to bring this in safely and really get in a good position. I think people have ... And I always say vigilance, not panic. We need to be vigilant. We need to be watching animals. We need to be paying special attention, but we don't need to necessarily be panicking and making poor decisions that are going to impact us in the long run because of something we're scared of today.

A.J. Tarpoff (35:44):
Yeah. It's almost like a flashbang grenade. It kind of goes off, goes boom, and then there's nothing else. There's no after effects, anything like that. It's a flash, it's a bang. It's like, "Okay, that happened?" Yes. But then we start looking at it and everything calmed back down. So for a lot of cow-calf operators, that's the scenario that we live with, with Theileria as it's moved across the U.S. What we're seeing today from the feeder calf aspect, it's a little bit different. A lot of what we're going to deal with is it's management and ensuring that we're reducing stress. We're acknowledging that some of the impacts that this disease can have where we've really turned to husbandry as our way out. That is truly our crutch. That is what's going to get us through some of these scenarios and reducing some of the impacts of Theileria. But it's low stress, managing those animals, managing the immune system, doing the best we can on the husbandry side. That's what pays dividends on reducing the impacts of Theileria on those feeder animals.

Cassandra Olds (36:51):
And these are things that ... Sorry, sorry. I was just going to say, these are things that are good for animal health anyway. If you do these things to protect yourself against, hopefully, having issues with Theileria, they're good for the animals anyway. They're good for the bottom line anyway.

Host Lynsey McAnally (37:06):
I have a question and, like I mentioned maybe before we started recording, I figure if I have a question maybe somebody else does. This might be a little bit of a chicken ... what came first, the chicken or the egg? If we have other insects, biting flies, other types of ticks that can transmit Theileria ...

Cassandra Olds (37:23):
So no other ticks that we know of in the U.S. can do it. Just the Asian longhorned tick.

Host Lynsey McAnally (37:27):
Okay, perfect. Thank you. But if we have other insects furthering that manual transmission, maybe if we're vaccinating, not changing needles, things like that, if that's the case, how did the Asian longhorned tick become the poster child for transmitting Theileria?

Cassandra Olds (37:45):
Oh, that's a great question. So I think it comes down to the fact that they were probably brought in in separate events and there's probably been multiple 'bring in' events. Hands down the tick is the most effective way of doing this. Now in Australia, in New Zealand, they had already played around with this idea of there are alternative transmission roots. So it was known, but it looked very different. And A.J. kind of alluded to this. It looked different there. They've got different production systems, they've got different breeds. And it was largely just ... it settled down and everybody moved on with their lives for the most part. So when it came into the U.S., we had the tick and the pathogen erupting around the same time and it was on the East Coast where the tick establishes itself very, very well. In any vector-borne disease that we talk about, the biological transmission is the most effective.

So that is the primary driver. What happened was we then started seeing situations here in Kansas where we knew this was prior to us finding the tick and we've still only had one recorded single tick. So we are not infested where we've got this everywhere yet.

A.J. Tarpoff (39:08):
And it was in a dog, by the way.

Cassandra Olds (39:09):
It was in a dog. A dog that was hit by a car on the road. So we were having cases of within herd transmission here in Kansas where we had no tick vector present. So that kind of set off alarm bells with me and I was like, "Well, hang on, there's got to be a different plan." And, to be honest, I had been focusing on this as a tick-borne disease. It's only when I started seeing these herds ... and the only reason we know this is because of Extension because we work directly with people. This is the importance of how important Extension is. When Extension drives research, we can do great things. So this was a producer I was working with. He had brought in cattle from out of state and had had a wreck and we were looking at it two, three years later and we had calves from these animals that had initially been brought in as replacement heifers.

And we're like, "Hang on, why are all these cattle infected? They shouldn't be infected." And we started seeing this in multiple places, then spoke to the folks in Virginia and they're like, "Yeah, we also suspected that there were other methods of transmission, but by the time we were suspecting this, we were overrun by the tick and we didn't have any negative animals left to look at." This idea that here, at least in Kansas, we were on the cusp of it and we still have the opportunity to really investigate this. So the tick steals the show and then we forget about these other things and it's only when we started looking at, "Well, what about when we talk about these states that are predicted to not ever be colonized by Asian longhorned tick?" We look at states where you may only get colonization in certain areas and then realizing, "Hang on, Kansas is one of these states." There are other states that we need to be better at ... And then adding in the relapse factor. We need to be better at educating people of all their risks.

Hands down, a tick is the most effective way. However, if you do not have the tick, you will still potentially have a problem. So just making sure that people are aware of all of the options. A.J., did I miss anything there?

A.J. Tarpoff (41:17):
The tick takes the show because it's the most important biologically, but we can't ignore all the other potentials. The research - sure, lice, biting lies or stucking lice, I should say - have been shown improvement to be able to transmit it, not biologically but mechanically. So as they share some of those lice from animal to animal and in close quarters during the winter, they can transmit Theileria. So if lice are effective, what about some of our other biting insects? Well, it just hasn't been proven, but that doesn't mean that it's not happening. And that's the piece that we need to be aware of.

Cassandra Olds (41:58):
Yeah. So we did find Theileria orientalis ... So, I'm getting ready to publish this right now and I'm really excited about it. We found it in the mouth parts of stable flies and we know that stable flies can transmit anaplasmosis and we've got this phenomenon ... I always say you don't have to be good at something if you've got numbers on your side. And if anybody's been out in the summer and been bitten by stable flies, you know. They've got numbers on their side. Our next step is, "Okay, can we prove that they are transmitting this?" They're probably not terribly good at it, but it doesn't matter. You don't have to be very good. If you're getting 10,000 bites per day, maybe one or two of them had a little bit of Theileria leftover and there you go.

A.J. Tarpoff (42:45):
We can't rule out some of those things. That's the key takeaway.

Host Lynsey McAnally (42:49):
I think it's really interesting to have this conversation because in some of the previous Asian longhorned tick presentations that I have listened to, it feels like when the presentation is given, it's typically, "Yes, there can be a problem with overpopulation." But then the conversation quickly moves on to Theileria. I think in a lot of people's minds, those two things are tied together and not necessarily thinking to themselves that it can be transmitted in other ways. I listened to a presentation last year sometime and there were some maps of the overlap ... Well, the spread of Asian longhorned tick and then the spread of New World screwworm and they overlaid those maps together. It was so interesting to me to see that. But I think when we talk about ticks, at least in my area. I live in a very dry area, the panhandle of Oklahoma.

We don't have as much of a tick problem here generally as we do a fly problem. And so - in my mind - I had kind of knocked off, "Oh, well, maybe we won't have to worry about Theileria orientalis," and you've just given me another thing to think on. Both good and bad there. Again, we're all individuals and we all have access to different information, maybe some of the same information. I'm betting that somebody listening to this just had a light bulb moment as well.

Cassandra Olds (44:07):
I always put up the slide, "No tick, no problem?" Because we don't think about these other ways. And forewarned is forearmed. My goal is not to get anybody panicked, but just to know there are Plan B, C, D and E. We need to be thinking about Theileria as a vector-borne pathogen, not a tick-borne pathogen.

Host Lynsey McAnally (44:35):
All right, listeners, the conversation was just too good and we ran a little overtime. Tune in next Wednesday for a special bonus episode of Angus at Work, where Dr. Olds and Dr. Tarpoff discuss options to reduce tick habitat, potential methods to knockdown fly and tick populations, whether keeping Theileria out of your herd is a realistic goal, and more. For those listeners already subscribed to the Angus Bulletin EXTRA, we will include a direct link in next week's e-newsletter. We promise you won't want to miss it.

Listeners, for more information on making Angus work for you, check out the Angus Beef Bulletin and the Angus Beef Bulletin EXTRA. You can subscribe to both publications in the show notes. If you have questions or comments, let us know at abbeditorial@angus.org and we would appreciate it if you would leave us a review on Apple Podcasts and share this episode with any other profit-minded cattlemen. Thanks for listening. This has been Angus at Work!