EAHAO #27 - "Theileria!" with Dr. Gregg Hanzlicek of Kansas State University Veterinary Diagnostic Lab

If you haven’t learned to pronounce Theileria, it’s time! ("TIE-leer-ee-uh" (thī-ˈlir-ē-ə).

Way-more-important though are the facts around the disease itself!

This is a longer EAHAO podcast - clocking in at just a tick over 14 minutes.   But each minute is worth it as guest Dr. Gregg Hanzlicek* provides the latest information on the disease threatening thousands of cattle, their owners, and of course, those who care for the health of the herds.

Medgene Cattle Team member, Mike Steilen conducted the interview in July of 2026, asking the questions so many are wondering, but don’t have the opportunity to ask.

Please share/forward with veterinarians and cattle producers alike.

*Dr. Hanzlicek is the Assoc. Director of the Kansas Veterinary Diagnostic Laboratory (KVDL).

Medgene - it's a new day for animal health care!
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The opinions expressed are those of the individual(s) and do not necessarily reflect the official policies or positions of Medgene.  Potency and efficacy of prescription platform product biologics have not been established. This product is prepared for use only by a veterinarian prescription.

Medgene’s prescription platform system ensures that all the ingredients that go into our vaccines are animal origin free.

#animalhealth #cattle #swine #veterinarian #largeanimal #agriculture #farmlife

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Transcript

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SPEAKER_00 0:05

Welcome to Every Animal Has an Owner, a mostly large animal podcast for veterinarians and the people that depend on them.

SPEAKER_02 0:15

To get us started, would you please introduce yourself and give us a little bit about your background and what you do?

SPEAKER_01 0:22

Hello, everybody. My name is Dr. Greg Hanselchek. I'm at the Kansas State Veterinary Diagnostic Laboratory and a little bit about who I am and where I came from. I'm a Kansas native. I actually attended uh Kansas State University and received a bachelor's in dairy science way back, uh way back when, and spent the next uh seven years as a dairy herdsman slash middle manager before going to uh veterinary school at Mississippi State University. And then after graduation with uh DVM, I spent uh the next 16 plus years as a bovine practitioner in the Midwest, primarily uh serving uh dairy and cow calf clients. And then after 16 years, I had an opportunity to come back to K-State and pursue a PhD in epidemiology. And uh when I finished that, I was asked to join the diagnostic lab here at K-State, and I've I've been here now 15 and a half years. Uh presently I'm the associate director of the laboratory, and I'm primarily responsible for our outreach program. And then we also have what's called the A Field Disease Investigation Unit, so I'm also uh in charge of that. Great.

SPEAKER_02 1:38

Thank you. So I'm gonna go ahead and and dive into the Tyleria discussion. Um, so Dr. Hanselchak, what is thyria and why should cattle producers be aware of it?

SPEAKER_01 1:50

Well, phalaria or thylariosis is the disease is called. It's a is a blood parasite and it's more closely related to what producers would recognize as a coccydia or crypto. It's not a bacteria and it's not a virus. And the reason uh producers should be aware of it is it is an emerging disease in the United States. Uh, it's caused by an organism called Bilaria Orientalis acheeta, which is not native to the United States. It's been here since probably about 2010. Uh, but it causes uh health issues in both uh young calves and adult cows. And primarily right now what we're seeing it in here are beef cows. I don't know that we've had any any cases in the dairy cattle populations.

SPEAKER_02 2:41

Okay, thank you. Um are you seeing any notable trends in Tyleria cases at the Kansas Veterinary Diagnostic Laboratory?

SPEAKER_01 2:49

So talk a little bit about the trends that we're seeing the laboratory. We we designed, I believe, was the first commercial PCR test back in 2021. Uh and since 2021, we've seen a huge increase in the number of tests that are coming in, primarily from the Midwest, but we've actually tested animals from 32 different states uh across the U.S. And what we've seen are as our as our samples have increased, uh the positive rate has gone from the first year of 6.7% of the animals that we tested were positive. And this year we're at 54%. Now, to my knowledge, every one of these samples has come from animals that were suspected of thylaria, not from cases or herds where they're doing surveillance. Uh, but we're definitely seeing a trend. Most of our cases right now are coming from areas just east of Kansas in native herds. Uh, and the rest of the cases to the west of Missouri actually are coming from animals that actually have been imported from the eastern part of the United States. How is thylaria typically diagnosed? To diagnose thyosis, we've got a couple methods, or actually, we've got one method and two samples. One again, animals that are alive. Uh, what we typically need from those is actually whole blood or blood collected and a purple top tube. And then for those unfortunate animals that have uh have died, the the sample of choice is a piece of fresh spleen. And the test we're gonna complete on it uh is a PCR, which is gonna look for a little piece of DNA of the organism. Uh we are close within a couple weeks of actually having an ELISA design uh for this disease, which will reduce the cost, and it's basically a it's gonna look for the antibody to thyria and not the not the DNA of the organism.

SPEAKER_02 4:49

So if I were a producer or a veterinarian uh in the field, I guess what clinical signs or symptoms should I be looking for? And along the lines of that, Dr. Hanselchak, how do I tell the difference between thylaria and anaplasma or anaplasmosis?

SPEAKER_01 5:07

So we get a lot of calls uh now because thyria is in the in the news and everybody's talking about it is how do I know if if I have an animal that's infected with a disease or or experiencing the disease? And for those producers that are familiar with anaplasmosis, it's very, very similar clinically to anaplasmosis, meaning we've got uh sudden death may be a part of it. A lot of times the animals will be open-mouth breathing, uh, their your mucous membranes, their vulva around their eyes will be pale. Uh sometimes, actually, that those tissues will be yellow. Uh, the animals sometimes are they don't walk uh correctly because their stalls uh star for oxygen. So all the clinical signs of those two are very, very similar. The differences between the two are we rarely see anaplasmosis in in animals under two. And what we're seeing now with thyria is we're seeing it both in adult cows and calves, but the area that we're seeing the most severe morbidity and mortality are in weaned beef calves. And so that's totally different than uh than what we see in anaplasmosis. How is it spread? So, one of the questions we get also is okay, how did I how did my herd become infected or how is it spread among animals? And it is it is a vector-borne disease, meaning it it is spread by insects. And the the one insect that is very important to this particular protozoa is uh the Asian Longhorn tick. And uh, if we if we listen to our colleagues in Australia and New Zealand who have dealt with this disease for a lot longer than we have, they they will say that if you have the tick in your geographical area, you will have thylaria. If you do not have the tick, it's very unlikely that you will have this particular disease. So this tick is very, very important. Now, there's some scientific evidence out there that does suggest that it can also be spread by sucking lice. Uh, there's even some uh in Europe that believe it can be spread by mosquitoes. And uh those of us in the Midwest, we certainly believe that it can be spread by horse flies, deer flies, and stable flies. Uh and then another very important way that it is spread is through uh multiple use needles. Anything that moves blood from a positive animal to a negative animal can transmit the disease.

SPEAKER_02 7:41

Are there any particular regions, production systems, or times of the year where cases are more common?

SPEAKER_01 7:46

So when we talk about when we typically see thylaria, we when we first started dealing with it, we assumed that it was going to be like anaplasmosis, where our peak times were late summer to early fall because it is vector vector-driven in the incubation period. But uh for thylaria, we're seeing it all year round. It and there's something different with this organism compared to what to anaplasmosis. So we're learning a lot, but I don't believe that we at this time believe that there's a peak period for thylaria. It's it's it's more like a year-long thing, and a lot of it has to do, that has to do with the fact that it's infecting and causing clinical signs in young animals.

SPEAKER_02 8:32

So, what should producers do if they suspect they have thylaria in their herd?

SPEAKER_01 8:37

So, for herds that uh that suspect they have thylaria, number one is uh there's lots of diseases that can mimic uh thylaria. And we talked about anaplasmosis is one of them. Uh occasionally we can have lepto, there's some other diseases. So don't automatically assume that uh because of those clinical signs that I mentioned that that your herd has thylaria. Uh first step is to get a veterinarian involved, have a good physical exam, complete it on the animal. And then, like I mentioned earlier, there's there's some tests that we can do to either rule in or rule out uh thylaria being a part of whatever's going on in the herd.

SPEAKER_02 9:18

You may have mentioned this before, and I may have missed it, but can I just add antibiotics to my feed or give them a shot?

SPEAKER_01 9:26

So we talked about uh how we diagnose it and how we know that a herd's infected. Of course, one of the questions that we have, which is very important, is uh how do we treat it? I mean, producers know that oxytocyclines are usually very effective against anaplasmosis. The fact that this is a protozoa, there is no treatment. Uh, it's very, very refractive to any of the antibiotics that we can use. And I've talked to close to over 200 producers and veterinarians now that have dealt with this. And overall, they all mentioned that there really isn't a treatment. The only treatment for this would be uh provide shade, provide food, provide shelter, provide water, make these animals as comfortable as they can. The majority of them will survive, and especially on the calf side. Um and so it's not a it's not a matter of giving an antibiotic, but just good animal husbandry is really the way to manage this once we have clinical animals in the herd.

SPEAKER_02 10:32

All right, thank you. How important is it to have a PCR that differentiates the various genotypes within that organism?

SPEAKER_01 10:38

So, talking about the different types of thilaria that are in the United States, there's actually three uh genotypes. One is uh thylaria orientalis bupeli, which is has been native to the United States. We do not consider it to be a pathogen. Another one is thylaria orientalis, which is not native to the United States, and we can find it in herds. And in fact, our PCR will will identify both Kitossi and IKEA. Uh, we we at this time do not believe that kitose is pathogenic. Uh, we do find it in about 17% of our positive samples. Uh and for us, and I think most of the people around the uh the world that do with thylaria, it is thylaria orientalis aikida. And it's it is important to identify it as the pathogen because if we're saying bufeli or we're saying uh kitosi are present, uh it may not be causing the disease, and we may be missing other diseases out there for the fact that we're just going down the down the wrong rabbit hole.

SPEAKER_02 11:47

What is your prediction for how thyria will affect the country three years, five years, ten years from now?

SPEAKER_01 11:53

So think in the future of what's going to happen with thyria is we've seen it move from the East Coast to basically Clear to California is where we can find it in animals. Uh, if if this tick is key, and this tick has very specific environmental conditions that it likes, it likes high humidity, tall grass, uh those kind of areas, then uh at least right now, we don't believe that it's phyleria is going to be found in the more arid areas of the United States, meaning the western part of the U.S. Um The thing we don't know is can our native ticks that live in other places of the United States, if they become infected by feeding on a positive animal, will they be able to transmit it? That's the thing that we don't know. So um because of the way animals move, in my opinion, in the next five or ten years, it's gonna be just like anaplasmosis. It'll be in in all 50 states. Um I don't think that we need to freak out about it. Uh what we see in the adult cows is just like anaplasm, it's it's not very detrimental uh in most cases. For me, the big concern is in weaned beef calves, and and there it there has to be some, at least in my mind, some association between thyria and respiratory disease, because with that combination are the cases where we see the biggest wrecks. And so for me, there needs to be some type of research out there to investigate the is thylaria contributing to this respiratory disease uh issue or isn't. And I think that that has to be in our future, otherwise we'll never get a good handle on it.