Baa's and Bleat's - The AASRP Podcast
Baa's and Bleat's - The AASRP Podcast
Domestic Deer Death and Disease with Dr. Amanda Smith
Join us for a discussion about the most common causes of death in farmed deer in the Midwest with Dr. Amanda Smith, an assistant clinical professor and diagnostic pathologist at the University of Missouri's Veterinary diagnostic lab https://vmdl.missouri.edu/
In this episode Dr. Smith gives an overview of the farmed deer industry in the US with an emphasis on the midwest and discussed her study of causes of mortality in farmed deer from 2004-2023.
This month's paper is titled "Causes of mortality in farmed white-tailed deer in the midwestern United States, 2004–2023" and can be found here: https://journals.sagepub.com/doi/full/10.1177/10406387241271416?casa_token=qKpG47_0zfgAAAAA%3A1qdAgjhmpwdxmLChLxcMMWKbVXYjtmiswVSwKrUfuUzXjgqc_RD2WbRRbWd2qMrtx9WP0o6AAA
Dr. Smith also mentions a study carried out by the University of Wisconsin titled "Cause-specific neonatal mortality of white-tailed deer in Wisconsin, USA" which can be accessed here: https://wildlife.onlinelibrary.wiley.com/doi/full/10.1002/jwmg.21260?casa_token=XifWnG1gdFEAAAAA%3Ah0ZVnTj096vRRAFKwD8Va-xmOYoP9_BtsMfqzDIZaxGbWJyy4Xxskevgu2hHXhqRmhhAzQS7NZVW
If your company or organization would like to sponsor an episode or if you have questions about today's show, email Office@AASRP.org
Hello, and welcome to the next episode of Boz and Bleed. Today we will be talking to Dr. Amanda Smith. Dr. Smith is an assistant clinical professor and diagnostic pathologist at the University of Missouri at their vetbag diagnostic lab. So you, we were just chatting before we started, and you're new, you're young, you're just out of your residency with your with a new job. So very exciting. Welcome.
Amanda:Thank you. Thank you so much for having me.
Sarah:Yeah, absolutely. So we always like to start with a little a little history about where you grew up and all the millions of universities you've gone to. So yeah, let's hear it.
Amanda:Okay, so yeah, I am actually originally from the Northeast. I grew up on Cape Cod, Massachusetts. So we did not have a large uh population of ag animals out there. It was mostly equine, which was my original passion, and like teeny tiny cute little hobby farms with a couple of little goats, really fat goats here and there. I didn't actually decide I wanted to be a vet until my senior year of college. I went to UMass Amherst, and at that time I was a working student at a performance dressage farm, and I thought I wanted to do horses for the rest of my life. And so I went into vetmed thinking I was going to be a high-end performance equine vet. And then when I got into vet school, I went to Oklahoma State University and I had a little bit of a crisis where the equine vets that I was seeing did really not have any time for their own horses, and they were just constantly seeing clients' horses. The work-life balance really wasn't there. I think it's changing a lot slower in equine than it is in a lot of the other avenues of vetmed that we see. And I was just like, oh, I don't know if that's actually what I want to do. So that kind of corresponded with our systemic pathology course. And one of our older pathologists walked in. And at Oklahoma State, the pathologists are like the cool ones. They're all like super hip and fun. And the pathology is like the real it's a really fun course. And so Dr. Confer walked in and he was talking about, you know, this great job where you're gonna see all these different species of animal. You never have emergency because they're dead. And I was like, you know, I could be interested in this. So as that course progressed, I started going over the necropsy lab. I didn't know what pathology was, I had never heard of that until vet school. So I started hanging out in the necropsy lab, started reading biopsies with them, and just got really involved. And I was fortunate enough to get a residency at the University of Missouri right out of vet school. So I have been here for the last three years, and then I was fortunate enough to get hired on as an assistant professor right after my residency. So I just passed boards this past fall. So yay!
Sarah:Congratulations, that is huge passing boards. That is huge.
Amanda:Thank you. I'm I was very relieved because I also had a baby in the last year, so I was like, ooh, how's this gonna go? So the University of Missouri is where I'm working now at our veterinary medical diagnostic lab. It is a full service lab. We are AAVLD accredited. We're the only lab in Missouri with that accreditation. We're also a national animal health lab network, level one lab. We are a tier one of the FDA Veterinary Laboratory Response Network, and we are also authorized by the National Poultry Improvement Plan. Um, we're a land grant university, so we don't just serve the university, we also serve the community. I would say more than probably 75% of our caseload comes from producers in the area. We're about 60% large animal, about half of that is cattle. The remaining half is equally split between small ruminants, camelids, and horses. And we also have a pretty thriving avian department, which I'm currently serving as an avian pathologist as well, which is a new thing for me, but it's actually been super fun. So yeah, it's a good time.
Sarah:Awesome, awesome. You know, maybe I'll just throw this out there. A lot of people don't understand that every state has a land grant, and that's kind of the ag school. In California, it's Davis, in New York, it's the public half of Cornell. In Wisconsin, it's the UW Madison. So most of times you can kind of pick out which one's the big ag school, but it's it's pretty important. Every state, you know, has this school, this university that's doing ag research and animal science stuff. So anyway, side note. So today we are going to be talking to Dr. Smith about a species we have not yet talked about on this podcast. We are going to be talking about deer, right? Whitetailed primarily, right? And so I've asked Dr. Smith to give us a little bit of a history on farmed deer, and then we will dive into her 2023 paper entitled The Causes of Mortality in Farmed Whitetailed Deer in the Midwest United States from 2004 to 2023. So this is another, we've talked about retrospective papers on this podcast before. So this is another retrospective looking back at why deer die in Missouri, farm deer primarily. So there's not a lot of hit by cars because that's what we think about with deer. So why don't we just jump into kind of the farm deer industry a little bit? If you could give us a background, talk about why deer are farmed, the differences in the different areas, and whatever else you want to tell us.
Amanda:Yeah, so deer farming is one of the fastest growing rural industries in the United States. Depending on your source, it is a between 2.6 billion and $7 billion a year annually industry with like all the labor and the veterinarians and everything included. So there's several different reasons why people farm deer. The probably most well-known version would be for meat, so for Vincent. I am certainly not an expert in economics, nor do I claim to be, but people in the deer space will argue that it's actually more profitable and better for the environment to farm deer than it is to farm cattle. So deer eat less than cattle do, they do less damage to pasture, and they're adaptable to a variety of different terrains. So you can keep them in varied spaces. Um they mature more quickly than cattle, and they also can have a reproductive life of longer than 20 years, which is much. I certainly don't do a lot of postmortems on 20-year-old cattle at my job. So that is that's one of the big pros that the deer people will tell you. Additionally, vencin is a little bit healthier than beef. So three ounces of beef is going to be about 160 calories compared to 135 calories in vencin. It has beef has between six and 15 grams of fat, depending on what cut you're getting. Whereas Vencin only has about three grams of fat. It also has 26 grams of protein compared to 23 in beef. It does have slightly more cholesterol than beef, not a lot, but a little. And it is much more expensive than beef. Additionally, people, you know, their mileage may vary, but think that venison has a gamier taste. And sometimes you actually have to add fat to venison in order to make it less dry because that part of what comes with that leanness is it makes the meat drier. So then, you know, that that fat content gets maybe a little bit of the wash. So those are kind of the big pros in terms of venison versus beef in farming. Additionally, people can collect deer hides for leather clothing production. In it's not so much in the mainstream kind of American culture, but in some traditional cultures and also in Asia, the velvet from antlers is considered medicinally important. So that's another kind of less commonly known product that you can get from deer, and it's renewable. They grow every year. And then what we actually see most in Missouri is actually deer that are bred specifically for trophy hunting. So these are animals that are genetically selected, just like we select cattle or goats for certain properties to grow really impressive antler racks. So 10 point bucks, 12 point bucks. They are then either bred and sold to game preserves in other states or in Missouri, or they are bred and then let out in game preserves in Missouri. So they provide like a luxury hunting experience at these game preserves where people will spend upwards of $5,000 to well over $10,000 to hunt to be guaranteed a buck with a certain number of points. So the trophy hunting industry is part of what we raise these deer for. And that is the majority of the deer that we have submitted to us here in Missouri. I my very limit understanding is that in some of the northern areas that like meat production is more of what they're focusing on in those areas, and that very, very broadly in the south and the south southern Midwest, that we have more animals that are being headed towards that trophy, trophy production. I don't know the exact percentages of like how many farms are trophy versus meat production, but my understanding is meat is a much larger portion of the industry on a nationwide level.
Sarah:That's interesting. I yeah, I mean, I guess you don't really see venison out in like stores or even at like farmers' markets. Everyone I know who eats venison shot it themselves or was given to it, you know, or it was given to them. So I'm wondering where these people are finding their, you know, avenues of market and stuff. And even we have a real problem here in Western New York with having enough. So yeah, it's gotta be kind of rough to to farm deer in an area that's not really set up with the whole industry and set like cows are, you know. It's fun definitely compare all the deer meat to cow to beef, because beef is like the standard, right? Yeah, for sure. If deer meat had been the standard, we would be saying, Oh, it's so fatty. Deer is so dry. But okay. I had no idea it was such a big thing in the United States. Like it's a big industry. Here we just consider them kind of like nuisance.
Amanda:Well, so think the thing is I in Missouri, I I mean I've lived in a few different states and I have never seen more wild deer than I've seen in Missouri. So we do joke a lot at the lab, like, what are we farming them for? They're everywhere. Right. So, but I I really think it's it's that trophy hunting, because you can go out and spend eight hours trying to just shoot a deer, and you're not guaranteed to find something that is worth shooting, never mind something with such an impressive rack. And this is outside of the scope of my study, but um, we do also have elk farming in Missouri, and it's the same thing, they're much more expensive to hunt. Those hunts are upwards of $17,000 a person. So they do also raise elk in captivity, and then fallow deer are the other probably most common species. I focus on whitetails because that's the vast majority of what we see. I think we only have maybe five or six animals that weren't whitetails in our archives, but in other parts of the country, fallow deer, seek a deer, red deer, those are also um animals that are farmed.
Sarah:Interesting. Since this is gonna be our December episode, I'm wondering if you know who farms reindeer.
Amanda:I don't know. We do have clients here that have pet reindeer, but I'm not sure of any that off the top of my head that produce them on like a commercial level. But we do have several, like the Anhouser Busch farm, the Warm Springs Ranch, they've got reindeer there. But yeah, so we've had a couple of of people that just have pet reindeer, and I don't know where they get them from. That's a great question.
Sarah:Santa's reindeer are probably all pets, I'm pretty sure. I think so, yeah. They would have to be. And I mean, I'm sure you've read online, like I have, that Santa's reindeer must be female because only the females still have their antlers at that time of year.
Amanda:That's a great I wonder who does Santa's network. Like, are those deer vaccinated? Do they have like a uh health certificate to be crossing the state lines? Do we think? Have they been tested for AI? Absolutely.
Sarah:Okay, now that we have a little bit better understanding of the deer industry, let's just jump into your paper. These retrospective papers, there there's not as much like materials and methods and all of that to kind of talk about there's a lot of data and like statistics, but it's important. It's important for these people who are farming deer to be able to be like, okay, these are the main things that I need to look out for. These are the bacteria that I need to worry about, you know, because when when we think deer, especially I went to vet school in Wisconsin, and so we thought, you know, a ton of chronic wasting disease, but that is not part of the study because these are farm deer, these aren't wild deer. And so no, there's nowhere for them to get that, right?
Amanda:Yes, and we actually do this lab does an enormous amount of chronic wasting disease surveying. So I went, I went down before we we started recording. I was like, okay, give me the the Eli 5 on the chronic wasting disease testing. And Dr. Delaney, who's our communications, was like, there is no easy explanation. So essentially the very most basic version is that the so CWD chronic wasting disease, it's a prion disease, so it's like mad cow disease, bovines, fun deform, and cephalopathy, or scraping or cell ruminants, and it is surveilled by both the USDA and also state organizations, and sometimes they argue over who's surveying what. They both have different testing requirements, but the moral is that it varies based off of what type of deer you farm. All farmed deer in Missouri have to have a permit, and the permit varies whether or not they are greening operations or hunting operations, but either way, they have a certain number of animals that they need to test every year to meet USDA standards. And then if usually they just use their mortalities if that satisfies the requirement. If not, they actually do have to call animals to fulfill that requirement. The Missouri Department of Conservation has its own different rules. They're less strict in what samples were allowed to send them for testing, and it gets very complicated after that. But we do have CWD in wild deer in Missouri, but we have never detected it, to my understanding, in farmed deer in Missouri. So we do not have to worry about that. In our deer population, we do still survey for it, surveil for it, but we do not have it currently. But in so I'm from Massachusetts. So in the summer we hire seasonal workers to scoop ice cream. And in Missouri, we hire seasonal workers to process CWD testing because that's how much we do.
Sarah:Yeah, I so I went to vet school in the early 2000s, and that was a job the vet students could do. We could go out and the hunters would come and we would collect brains or heads or whatever for testing, which I don't think they do anymore because I think Wisconsin's like, yeah, we know it's here. Like the point of throwing all this money in, you know, to doing huge amounts of testing. And, you know, they really encouraged, like, I remember they had an earn a buck program to try to get people to hunt more does, but that's also a side note. So who jumped into the records at Missouri looking back? So people and it's people could be vets, they could be producers, whatever, either brought in a whole deer, or for those of you who do who haven't had this done on your farm or don't know, vets can do necropsies, which is the vet version of an autopsy, and just collect samples. So it's like a piece of the liver, a piece of the heart, a piece of muscle, and send them in to get a diagnosis of how this animal died. And so you put that together and said, okay, let's figure out the main causes of why these farmed deer are dying.
Amanda:Yeah, and I think these retrospective studies are they're really important. I know I'm biased, but these all of these universities with labs, diagnostic labs, just have like treasure troves of data for usually like about the last 20 years is basically when everyone started putting things online. And we just have all of this information and it's just sitting there for the most part. And so I'm hoping to start kind of mining it out. And my goal is to create actionable data for producers and for veterinarians. Like you were saying, what bacteria are we seeing? So, what's the most likely thing that I should be putting antibiotics in this creature like while I'm waiting for my culture results? That's kind of what I'm hoping to provide is information that is actionable to the people who are living in Missouri and raising these animals. Hopefully, it'll help save the animals, it'll help save the producers' money, keep our vets employed. All of those are good things.
Sarah:And even potential vaccine information. I know these no vaccines are going to be made for these species, but no, we do have vaccines for deer.
Amanda:So these really high-end trophy operations will pay companies to make vaccines based off of specific viral isolates, specifically of epizootic hemorrhagic disease and blue tongue, which are super closely related. We'll get into that. Blue tongue is obviously a problem in your cell ruminants, and then epizootic hemorrhagic hemorrhagic disease is the deer version, and they will pay companies to make them their own vaccines based off of whatever strain of that virus they have.
Sarah:Okay, so these are more autogenous, specific for the farms, kind of like in cows, how we will have pink eye vaccine made specifically for that farm. Okay, okay, that makes sense. So nothing commercial, no, but it's worth it for these guys to pay to have these specific ones made. Okay, that makes sense. Okay, so you found 388 cases. Okay.
Amanda:So 388 cases, like you said, 65% were whole carcasses, 35% were those CLD crop seed tissues that you told us about. So in terms of the gender of the deer that we're seeing, there was pretty much equal, equally male deer to female deer. Age, about 50% were adult deer, 50% were fawns, which we defined as deer under the age of one. Seasonality, we had 54% of our animals die in the summer. So in that area, what we sort of suspected, in that area, the juvenile mortality was highest, and that kind of correlates with deer fawning season. So we're talking about like neonatal mortalities in that space mostly. Then we also had 86% of our total population died of infectious causes, and that is a sharp contrast to some of the other studies that have been published. There's been a really great one out of Wisconsin. Shout out to UW, where they had trauma and parasitism being their most common. I think one of the important differences there is that what some of these other studies have done in the north where they found trauma a lot more frequently was they actually surveyed producers, and the producers were reporting trauma as a cause of death. Specifically, they talked about trauma, not like interspecies conflict, but mostly trauma to do with handling. So I'm sure you can imagine, like working deer isn't something that most people have facilities set up for. So a lot of injuries would happen kind of in that space. And I think in our cohort, people just didn't bother sending us those deer because they know why they died. So it's not really worth their money to send us a deer with a broken leg because they're like, well, that's a broken leg.
Sarah:And that's a piece of this puzzle. Like you guys sent the mystery animals, not that okay, we know, you know, you were a twin and you didn't get enough colostrum, and so you died, you know, like if it was clear to the producers, yeah, they're not gonna bother spending their money. Right. So I don't know how it works at your lab, but when I was in Vet School, Wisconsin, if you were a patient there, if the animal was a patient there and died, they could be meat craftied for free.
Amanda:Yes, that's true here too, but none of these animals were hospital patients. These are all submitted from producers.
Sarah:So Cornell has a special deal for when animals are from farms just to help farmers get more information to encourage farmers to submit animals. Yeah. And so I don't know if most vet schools have something like that to encourage people to bring animals for in for more work.
Amanda:So we do that with the teaching hospital cases. They get a free gross necropsy and a free histology examination as long as they paid for an exam fee. Special like ancillary testing is additional charge to the client. Most of our large animal caseload comes directly from the producer. Usually the only thing, and I really just think it's a matter of like they're not bothering to send them to the tertiary referral institution. Like most farmers are gonna like make the decision to euthanize long before they end up here. So our food animal cases are usually like really weird things. And we're like, ugh. So stuff that like the you know the referring back couldn't figure out and they ended up there and then they ended up with us. Um whereas our pneumonias aren't going through, you know, the school. So those are coming from producers. But we really don't have difficulty with our producers submitting animals. The vast majority of our large animal caseload, including these deer, are usually animals that were submitted because they're having a herd health issue, and they've either selected one to sacrifice or just sent us one that they think is representative of the herd. And I think this is an important kind of point to the producers that are out there. If you are going to choose an animal to sacrifice, which is a really hard decision to make, but if that is something that you think is necessary to get information on your herd, sending us one that hasn't been treated with antibiotics is gonna be massively helpful to actually coming up with a diagnosis. It's really frustrating for us and for the clients when we have a cow that has the most beautiful pneumonia you've ever seen and we don't culture anything because it's been given a bunch of antibiotics. And of course, the goal is to keep that animal alive. So I, you know, I understand completely. But if you're gonna pick someone to send to decropsy, try to pick someone that hasn't been treated. Um that is gonna give you the most diagnostic information.
Sarah:Yeah, that's great. That's a great point for sure. Okay, so primarily they're coming to you because they're infected with something somewhere, which makes sense because these animals got sick, the people didn't know why, they probably treated them, but then they still ended up dying. So they come to you and they're like, What did we miss? Why didn't our antibiotics work? What's going on?
Amanda:Yep. So the in general, the southern Midwest, which is kind of where we are in the south, we just have way more infectious disease than y'all have in the north, which is very fun for diagnosticians. It's not so fun for producers. So 41% of our animals that died of an infectious cause died of pneumonia. That was our most common finding in these patients. Then it was septicemia, that was 20%. And that was most common in our juvenile animals, so like in the unatal septicemia, failure, passive transfer, that kind of thing. Failure of transfer, past immunity, my bad. And then also about 20% had an enteracolitis, which was also more common in our juvenile deer. In our adult deer, it was pneumonia was most common. So of our non-infectious causes, emaciation and trauma were tied per first, and they were still only 1% of the animals that we saw. So a really, really, really small um number of animals were dying of non-infectious causes in our group. So for pneumonia, that was our big, our big ticket item with this cohort. Something that has been kind of discussed like privately in the in the deer space is coming up with a servid respiratory disease complex similar to the bovine respiratory disease complex. And just like in cattle, we believe that it's a mixture of environmental issues, individual susceptibility, load of the pathogen, be it virus or bacteria, and of course, strain of that pathogen too, certain viral strains in certain years just seem to be worse. The most common bacteria that we isolated in our group was Truparella pyogenes, and our records go back far enough that it was still called whatever it was, like actinobacter pyogenes back in the day. So that was fun. I was like, oh, this is a while ago. So, and that is true in other studies where they have found pneumonia as a significant problem. They have also cultured truperella as the main cause. What is interesting about that is that truparella isn't a primary pathogen, typically a secondary invader. So that is to say that generally, if you are exposed to truparella, you won't develop disease unless there's something else already wrong with you. In cattle, what we typically think is that there was a viral infection that predisposed. So one of the key features of your immune defense against respiratory disease is what's called the mucosiliar escalator. So it is these little cilia that like beat in the trachea and they move pathogens from your lungs up and out and make phlegm and pop it out. So viruses will damage that mucosiliar escalator. And instead of being cilia that beat, it just becomes a slide. And so it allows overgrowth of some bacteria to just get in that wouldn't normally be able to get in. And then damage that that virus does to the lungs can allow for bacteria that are just normally there to overgrow. Like manhymia is a good example of a bacteria that is normally present and is allowed to overgrow and become a huge problem in our cattle population, smaller problem in our deer population, but still, still still poked its little head up. So we wonder then like, were these truparella animals, did they have a different bacterial infection? And they were treated with antibiotics, and that's why we're seeing the truperella. So those are questions that remain to be answered. But regardless, that is our most common finding, and it's also repeatable in different studies of deer. We also saw quite a bit of pastoral moltocida mycoplasma, specifically Mycoplasma bovis, and mycoplasma ovineumoniae, and Bibersteinia triholosi and Fusobacterium necrophorum. Fusobacterium was almost always a copathogen, and it was most commonly seen co-infected with Truperella. So Bibersteinia, to kind of compare to some other studies, other places in other parts of the country, they saw Bibristinia at a higher frequency than Mycoplasma. For some reason, we're seeing more mycoplasma here than Bibersteinia. In 18% of the pneumonias, there was a viral component detected. I think in reality, that number is probably a lot higher than 18%. It's just that our methods of detecting viruses aren't very good if it's not like pretty acute in the disease course. So they're not going to be PCR positive for these viruses a lot of times by the time that we see them. And sometimes we could do immunohistochemistry to look for the viruses, but we don't have immunosochemistry for a lot of the deer things that we're interested in. So I do think we're missing out on a lot of the viral stuff that we're seeing that we theoretically should be seeing.
Sarah:Do you know what the most common antibio antibiotic that these firms are using?
Amanda:I do not know. I know that they have them and they treat them, but I don't know exactly with what. I would imagine it's a large animal toolkit.
Sarah:Yeah. Like, I mean, are they all starting with oxy tet and penicillin and then moving or because they're so hard to handle, are they starting with like long acting, hard. I would guess. I would guess the latter.
Amanda:Because yeah, these aren't pets and they're not like they're hard to work. I mean, you can't really run it. I guess you could run a deer through a two, but it's probably trying to work longhorns, you know, like it's really just hard and they're not cooperative.
Sarah:Yeah, I wonder if they're getting V V VFDs and getting it in the feed and stuff like that.
Amanda:So yeah, that's a good thing to look into for sure.
Sarah:Like oxyte. Which I mean, the reason I asked that is because what bacteria were killed before they got there, right? Yeah, that's what we're curious about too. Yeah. That'd be an interesting piece of the puzzle. Okay. So lots of pneumonia in there. And then septicemia, just to make sure everyone's clear, that can also be pneumonia. It's just that it's also now everywhere else. And that's really common in the babies because they, you know, with them, it can start like more with their umbilical cord or other things and kind of go everywhere. Did you split up the different causes by age?
Amanda:So we did. And in the younger animals, we saw septicemia and enter colitis much higher than pneumonia. And also I had to sort of, so when we were putting this data together, there are many different pathologists that are performing these diagnoses over the years, and everyone has different styles. So I had to sort of go through and be like, okay, they didn't diagnose this animal with septicemia, but it had multifocal random hepatic necrosis and interstitial pneumonia and splenitis, and all of those three things together equals septicemia. So I would have to kind of go through and try to be like, all right, like in a you know, culture D. coli or something like that, and put those pieces together to try and like come up with an actual like diagnosis for that case if it had like five things that were like considered wrong, but I was like, Okay, but what does that mean? And if we're seeing certain certain disease processes together, like it means we have a systemic bacterial infection. So that was much more common in the younger animals, like you were saying. And sometimes they did have a pneumonia, but an interstitial pneumonia, and they usually also have other other findings suggestive of septicemia, and then they got booped into that category as opposed to being part of our pneumonia, which generally were more of like bronchonaumonias, pleuroneas, that sort of thing for animals that were diagnosed like primarily with pneumonia. A couple of interstitial pneumonias that didn't have lesions in other areas, which you can see with viruses, but those are mostly like kind of your classic bacterial, you know, craniodorsal distribution, bronchonaumonias.
Sarah:Okay, okay. Yeah. So I mean, my thoughts are that, you know, they were seeing disease, they gave them antibiotics at some point, they get better, they brought it in. And so maybe these animals, you know, weren't showing horrible symptoms of pneumonia before they passed, because as we all know, these prey animals are like, no, no, no, no, I'm fine, I'm fine, I'm fine. Actually, I'm not fine. You're not fine. All these sudden deaths. Right. There's all these like, and I feel like deer have got to be more like sheep, like, you know, I'm good, I'm good, I'm good, I'm dead, and there's no in between, I'm guessing. Sure.
Amanda:Yeah, and I think that's definitely true. And what is also important, I I think, is the management of these animals. So in a lot of instances, they're being kept in much higher stalking densities than you would expect in the wild. And so they're just swapping bacteria and viruses back and forth at a much higher frequency than you would see in the wild where there's a couple of deer hanging out together and their friends are a mile away, as opposed to having, you know, 100, 200 animals in a smaller location. So I do think that that is important in the development of these diseases and the transmission of these diseases is just sort of how the animals are handled, how stressed are they, how many are there, how much bacteria is just in the environment? Like, you know, are we all fawning in the same place that we're, you know, going to the bathroom? Like, what does that look like? And I think that's all important.
Sarah:Yeah. All right. What else interesting facts did you pull out of this data that we need to know?
Amanda:So viruses were one of the things, one of the questions that I had kind of going into this. Our producers, our clients, are always really worried about epizootic, hemorrhoidic disease, virus, and blue tongue virus. So, for those of you that are not familiar, those are both orbiviruses and they are spread by culicoides, which are biting midges or noceum. They, that insect is more heavily found in the southern part of the United States, not just like the southern, but like the southern half of the United States. And so cattle typically are asymptomatic, but deer, sheep, and goats all will typically have variably severe disease from blue tongue and episodic hemorrhagic disease. What we kind of traditionally see will be like a location, we'll just have like a crazy outbreak that will have variably high mortality. It can be over 50% of the animals in a few days. And we just see it kind of periodically. So I would guess it's strain related, like this is just a particularly nasty strain of the virus. The clinical signs aren't specific. Fever, edema, like swelling in various places of the body, decreased appetite. So not necessarily things that you're gonna notice right off the bat, especially if these are animals that are out, you know, in a large space and that they're just getting like a visual inspection. So we actually that is like probably the biggest thing that our our producers want to know about. Like there are always like tests for EHD, tests for EHD. And interestingly, we actually only found it in 47 animals. So 12% of them were actually PCR positive for episodic hemorrhagic disease virus. And of that, only 12 or 3% were actually diagnosed with episodic hemorrhotic disease. So it's unclear whether the virus was just an incidental finding, like they were infected but they weren't clinical, or if it was playing a role in their other disease. The most common diagnosis in deer that were positive for episodic hemorrhotic disease virus or EHDV was pneumonia, then pulmonary idiom and congestion, and in animals that were diagnosed with EHD, they typically had myocardial hemorrhages, but like pretty non-specific findings, like you're just seeing little streaks of red in the myocardium, certainly not something as striking as a colitis or a pneumonia or like a tumor. So subtle lesions and less animals actually positive than I think we were expecting to find. Okay. Well, that's pretty good. Yeah. Yeah. And then I guess colitis, interacolitis was the next one of the most common with our, I guess we technically sepsis, so we can go sepsis first. Sepsis was E. coli was most common, and that is that it can be hard because E. coli is everywhere, and it's really easy for it to be a contaminant. It also absolutely can be a pathogen that causes septicemia, but it's one of those ones where like it could be E coli bacillusis, but it also could be something else that we're missing. Then we also had staph intraparal pyogenes, those were our second most common mycoplasma and Claustinium perfingens. We also saw the most common virus was EHDV, but that was only in four animals, so not probably not related. And that was 72% of our sepsis cases were juvenile animals, so overwhelmingly, those animals under the age of one. And it was also most commonly diagnosed in the summer. So our thought was that that was probably like a neonatal septicemia, failure of trans repressive immunity, the onphylocobitis, or that navel ill was kind of our thought for those creatures. And then for enteritis and enterocolitis, just like in most of our other species of our other ruminants, E. coli and cluster and perfringens were our most commonly diagnosed at E. coli for 64% of cases and cushion perfringens. Again, those can be challenging to interpret.
unknown:E.
Amanda:coli is normal flora, and cluster and perfringens are both normal flora in animals greater than seven days of age. So they could represent significant pathogens, or they could represent the normal flora. You can do isolate typing for E. coli to demonstrate virulence, and you can also do toxin typing for clutchinum perfringens. It is expensive and it is rare that people will elect to do that. So we did not have that additional testing done by our producers. We also saw Salmonella in a couple of cases, Pseudomonas, Clostrodiodes, Diphysil in one animal, and Campylobacter, jejuna, jejuna in another animal. We also found bovine viral diarrhea virus in five of the animals that we saw with Enerritis. Also a couple of bovine coronaviruses, bovine rotaviruses, and a nonspecific herpes virus that just sort of was popped up in there. So the herpes virus thing is a little bit interesting because moly-nate control fever is a pretty significant pathogen in some of our servid species. We only have a nonspecific herpes virus, so it isn't specific for the ovine herpes virus too. So we don't actually know if our animals that we diagnosed with that were positive for this general herpes virus PCR had malignate control fever, their clinical signs didn't fit, or if they just had some other deer herpes virus that we haven't seen.
Sarah:Interesting. And yeah, did I read it right? You didn't find a lot of parasites.
Amanda:No, so we did fecal smears on 45%-ish of the or fecal floats or smears, and coccydia was most commonly found, and that was in 20 animals, so 11 personlides in some crypto in some of the fawns, and that is considered a significant pathogen of fawns. A couple trichostrongyles, a couple giardia, but really not that many. I think I don't know that we saw any like flukes, whereas flukes are considered a pretty significant problem, especially in elk in some other parts of the country. And we certainly see them in cattle around here, so they're they're in the area. We just really didn't see them in our deer. So yeah, we saw less parasitism than I think I would certainly have expected, considering what we see in our small ruminants and our camelids and other ruminant species around here.
Sarah:Well, that's good. And I mean, maybe these guys very actively deworm.
Amanda:It is recommended on the deer hobbyist sites to deworm.
Sarah:So if they're taking the advice of the deer hobbyists, I'm sure they're being dewormed to an inch of their life, honestly. So probably, yeah, probably the concern about resistance isn't in the forethought of their minds. But maybe I'm wrong. I shouldn't generalize. Okay. Um, what else? Boy, we really hit most of it, haven't we?
Amanda:Kind of a fun fact that is, I don't think, super relevant to the deer in general, but I did have two tissers disease in um two fawns, so that was kind of fun. Um, that was unexpected. But yeah, they had little tissers, tissers leave.
Sarah:Tell our producers what that is up here in the north where we don't know where that is.
Amanda:Oh my gosh, you guys don't have tisserous disease. Oh so tisers is caused by Costrinium philiforme.
unknown:Okay.
Amanda:It is a fun bacteria because it has really classic lesions in specific generally specific species, but every once in a while it'll pop up in others. Like recently, there was a weird one with perenal dermatitis in kittens. So would have thought. But classically, it causes a triad of lesions, hepatofecrossis, myocarditis, and a typhocolitis. The myocarditis and typhocolitis are seen most frequently in lab animal species. So gerbils are actually most susceptible to scissors. There's your fun fact for the day. Okay. Mongolian gerbils. And um, we'll see it in rats in bulls, who are the Other kind of classic species for tezzers, they almost always get hepatitis and they rarely get the other two lesions. And our two fawns both had hepatitis without myocarditis or typocolitis. But it classically causes this multifocal random hepatic necrosis. And then on the edges of those lesions are these like haystacks, or some people call them like Chinese characters. So there's like these little stacks of these rod-shaped bacteria. And that's the classic histologic finding for tissers. It's a super classic disease. It's on all of our board exams, it's on the Navli.
Sarah:So we're just come in as these little yellow things that are dying, I'm guessing.
Amanda:So yeah, two full two fulls. Tuffons had fissors, so it was kind of fun.
Sarah:Okay. So I think we hit everything. Okay, so what's next for you? What's next for your are you gonna continue looking at deer or so?
Amanda:Yeah, I have kind of a couple different balls in the air right now. In the deer space, Lorelai Clark at Wisconsin, she works at their vetmed lab, and her paper on deer mortality in Wisconsin was um a big influence on this paper. And so she reached out to me, which I was like, it was like a celebrity. I was like, oh my gosh, Lorelai Clark. So she wants to do a collaboration in the future looking more at like management questions of these deer, like how are they being managed? Are we running them through shoots? Like, what's the stocking density? Questions like that, which I do think are important and probably would change sort of what diseases we're seeing. And also in better defining this surveyed respiratory disease complex, and whether or not we should have like a standardized set of tests that we do in all deer cases, kind of similar to how we have in cattle, and in you know, not so much with but like with pigs for diarrhea, like there's just a certain test that you do for all of our large or cattle pneumonias, all of our pig diarrheas, things like that. So that is something that we're gonna work on a little bit together. So I'm pretty excited about that. Hopefully, we can get some some more data and some information from farmers outside of deer. I am also putting something together about game bird mortality that we see a lot of game birds like pheasants, chuckers, which I only learned out of Google what a chucker was, or a few little partridges. And yeah, with quails, people farm those species here as well. So coccidia, spoiler alert, kills a lot of them. So that's something that I'm working on. And yeah, so you know, we'll see what we what we come up with.
Sarah:Fun. All right. Okay, so if anybody has any questions about this paper, there'll be a link to it in the notes. Dr. Smith's contacts will be in the podcast notes. And so our final question is you probably read it. What do you see is the next problem that researchers need to think about and address in small ruminant medicine?
Amanda:So what we have these fun like food animal rounds where we meet up with the clinicians and talk about cases that we've seen from them or things that they've seen and then had submitted to us. And one of the things that we talked about recently was small ruminant pneumonia. So how that differs, I think a lot of times you kind of treat it similar to large ruminant pneumonia, but they're not large ruminants, they're their own special little breed of fun and joy. So I do think that looking into like what are we actually seeing in in those species, I think that's something that would be really interesting, as opposed to just assuming that it's the same as what we see in cattle. Right. How does that maybe change our approach to testing um and to treatment before they get to get to us? So that's kind of one a question that I think I would like to see answered. And then I mean, of course, this high path avian influenza deal. I think that is not going away anytime soon.
Sarah:So I think there's gonna be a lot, a lot going on with that. All right. I like that one. People usually don't get that specific, but I appreciate that. Well, Dr. Smith, thank you so much for joining us today on Voz and Bleats. And it was super fun to talk about a new species today. I loved it.
Amanda:Yeah, this was super fun. So I'm so delighted to be here.
