November 21, 2016

(Dan) Hey folks, welcome to DocTalk. We’re going to have a great show today. My guest, Dr. Steve Ensley, who’s a Veterinary Toxicologist, we’re going to run through a series of different toxicology issues he’s been seeing out in the country in different cases. It’s just remarkable work that he does here at Iowa State University. Thanks for joining us today for the show.

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(Dr. Dan Thomson) Dr. Ensley, welcome to DocTalk. (Dr. Steve Ensley) Thanks a lot. I appreciate being here. (Dan) You bet. Folks, we’re “On the Road” at Iowa State University. I’m here with Dr. Steve Ensley who’s a Veterinary Toxicologist. He’s the head of the Veterinary Toxicology Section here in Veterinary Diagnostic and Production Animal Medicine at the College of Vet Med at Iowa State University. Kansas native and I’m glad to shoot this here with the nice Flint Hills in the background. Brings me back home. We’re going to talk about toxicology and some of the issues that we’re seeing, and lead is the first one we have on the list. (Steve) All right. We’ve had a pretty devastating case of lead toxicosis in the feedlot. Actually, it’s a feedlot and some cow/calf pairs. A lead battery from the tractor accidentally got mixed in with the feed and we’ve got about 85 dead animals from the feedlot and another 10 cow/calf pairs out of the 15 that have died from northwest Iowa. It’s been pretty devastating to the producer. He’s trying to sort out food residue issues on the live animals is another concern. Plus, how we dispose of all the dead animals with the significant lead exposure. The typical cases we see, calves when they go to grass in the summer in May, may get exposed to the sensor batteries and consume lead that way. This case is fairly rare, but it’s high-dollar volume and big impact. (Dan) So on the live-animal side I assume you’re going to have to do some sort of muscle biopsy or tissue biopsy to see where we’re at. (Steve) Correct, so the food residue issues with lead in the muscle, liver, kidney, blood, we can check whole blood and hopefully, that’s going to be reflective of what the other levels are. We’ve got samples right now and that’s what we’re looking at lead in the bone, in the muscle, in the fat and other tissues too. (Dan) The other interesting toxicology cases with these indoor facilities being built is the hydrogen sulfide issue. (Steve) Right. In the last 10 years confinement buildings for cow/calf operations and the feedlots have been increasing in Iowa because our land costs are expensive. We don’t have the land to build or to house animals, so we built a lot of confinement buildings. This year, in the last two weeks, we’ve had issues with hydrogen sulfide from the pits getting up into the floor where the animals are causing significant death loss on those facilities too. (Dan) Well, when you look at intensifying agriculture, honestly, there’s some things that we’re going to see. Has there been a — the pits, it was deep pack for a while. Now we’re seeing more pits being included. (Steve) Right and I don’t really understand why the pits have gotten popular again. The deep packs, we didn’t have the hydrogen sulfide issue with. In Iowa, we’ve got to get the manure hauled out in a timely manner. We’ve got a short window time for when the crops are harvesting before it freezes. It’s always an issue trying to get the pits complete before we run out of time. It’s a significant issue for us because Iowa’s corn ground is $20,000 an acre, so it’s hard to put animals on. (Dan) Corn is king. We’re going to wrap up here. Watch for the batteries on lead toxicosis. Watch your pits on hydrogen sulfide. More with Dr. Steve Ensley from Iowa State University after these messages.

(Dan) Hey folks, welcome back to DocTalk. We’re “On the Road” in Ames, Iowa, with Dr. Steve Ensley here. He’s a Veterinary Toxicologist and the head of the Veterinary Toxicology Section. We’re thankful to have you on the show and talk about issues. We’re going to talk about poisonous plants, and some of the issues that you’ve been seeing lately with poisonous plants. (Steve) Poisonous plants this time of year can be an issue because we gather cattle. Sometimes, we gather cattle, put them in a pen, hope to get them all worked that day. We don’t, so they stay in there overnight and they’re hungry and they’ll eat the plants in the pen that can be an issue. The two biggest issues we see and right about when we have frost are cyanide, or prussic acid poisoning with the feeds that they can consume and also nitrate toxicity. Those two, we do a lot of testing for that, but it’s a big issue even in Iowa where we don’t typically have drought issues. (Dan) Talk to me a little bit about how it occurs at the time of frost or what’s the association with that? (Steve) What the prussic acid or cyanide toxicity associated with frost is the cyanide’s contained in the plant but it’s separate from the enzymes that can activate the cyanide to produce the cyanide. When the plant is crushed or we harvest that or we make silage out of it, we get a spike in cyanide release at that time. Freezing will do the same thing, it will fracture that plant, allow that cyanide to get access to the enzymes, it will activate cyanide. The 72 hours post-frost is a big risk time, we don’t to feed it or ensile it, or and green chop it and use it then. The varieties we have produce less cyanide than we have had in the past but we still see that as a constant issue. It’s an acute toxicity, die rapidly, we do have antidotes but the issue is they can die within a half an hour when they consume that; it’s quick. It’s very quick. (Dan) Pretty quick. When we think about poisonous plants, what are some of the plants people should be thinking about or looking out for? (Steve) Probably the number one plant that kills more animals in the Midwest than any other plant is actually Japanese Yew. It’s an ornamental plant and it’s planted around the houses. People harvest or clean up the house, trim the fences or trim the bushes and then throw it over to a brush pile. A handful of leaves will kill a 2,000-pound bull. They’re very sensitive to that and they don’t tolerate that. We have no any antidote for that and it is very acute. Again, it can kill animals within minutes actually when they consume that. (Dan) If you’re trimming up the trees and shrubs around the house, don’t be throwing them out in the brush pile where the cows are, right? (Steve) Right. It looks like cedar, a lot of people think it’s a cedar bush but the Japanese Yew is a common ornamental and the toxin it contains is very, very potent and it will kill. It kills everything but deer, people plant it to kill deer, it won’t kill deer but it can. It’s a highly poisonous plant that we deal with. (Dan) What about acorns and buckeyes? We have that on the list and we got about a minute to take commercial but- (Steve) We see the potential for acorn toxicity, oak trees in the pasture is a real issue every year, but usually it takes a perfect storm of short grass, an early frost and the animals are hungry, will drop acorns and they will over consume because that’s all they had to eat. Even though every pasture we have in the Midwest has oak trees either in the pasture or next to it, it’s a potential every year but we don’t see that often. This year what we — buckeye is also an issue; we had a good buckeye toxicosis in Nebraska, so that’s always fun to see. (Dan) I saw one where the calves, you open up the rumen and there’s full of buckeye. (Steve) Right. That’s always what I tell students, if an animal dies from acorns or buckeyes, you won’t miss it because when you open them up you have a 40-gallon rumen with 50 gallons of acorn and buckeyes. You’ll wonder how in the world they could consume that, but they will. (Dan) Well, we’re going to take a break folks, we’re going to come back and talk more about toxicology with Dr. Steve Ensley.

(Dan) Hey folks welcome back to DocTalk. Dr. Dan Thomson here with Dr. Steve Ensley. He’s a Veterinary Toxicologist and the head of the Veterinary Toxicology Section here at Iowa State University College of Veterinary Medicine. We’re proud to call him a fellow K-Stater and Wildcat as well. We crossed paths – you went to K-State and teach at Iowa State and I went to Iowa State and teach K-Staters. (Steve) Yes, I get to have a lot of interaction with Dan, that’s always great. I’d say I taught him all he knows about toxicology. (Dan) He did in veterinary school and as you can tell, I got a pretty good education and understanding of toxicology and its importance. But Steve, if water deprivation and urea toxicosis is a couple of? (Steve) The issues with that, the urea toxicosis, this is the time of year when if we’re short on protein we can add down protein nitrogen to the diet in a relatively inexpensive way but it has to be managed well. We see cases where animals over-consume urea that they have a hard time mixing it in a ration or they don’t get the — if they are restricted to one pound of protein a day, if they have access to more and they over-consume, again, that’s a toxicosis about like cyanide or nitrate where it’s very acute. Within half an hour when they consume that depending on the dose, we can start to see clinical signs and acute deaths. That’s one of the typical management errors that we see in the fall and wintertime because that’s commonly fed. (Dan) We always tell them no more than 1% of dry matter as the urea rule. If you can keep it that way, we’d be safe. (Steve) Right, Dan is a nutritionist. I don’t pretend to be a nutritionist, so I always visit with him to get a straight stories. (Dan) I cause the problems [laughs]. (Steve) Right. We see with liquid supplements, particularly if they’re not managed correctly, if they’re not agitated prior to use, or they’re put into a tank and the tank gets low, it’ll concentrate sometimes. It’s a common feed additive, very inexpensive and something we will use, but the potential for a toxicosis is high. (Dan) You have water deprivation, but water deprivation and water toxicities can be issues, right? (Steve) Right. We see this time of year, especially as we get into the colder parts. If we have animals, their water device gets frozen or they can’t get — If they’re watering from a device that freezes over and they don’t get access to water. In the wintertime because of less heat and less high temperature, maybe they can tolerate it for a longer period of time, but we do see even in cattle and swine in Iowa, we see an issue where the waterlines freeze, they don’t get water. In cattle we still see the issue with the owner, maybe they’re supposed to break the ice every day or make sure they have water and somebody’s not paying attention or they missed that detail. We typically see, as long as they don’t have access, they don’t see signs as when they get to re-access to water after they’ve been deprived for a period of time is when we see the issue. Again, it can be a very acute toxicity also within an hour to two hours. When they get access to water, again, you’ll see clinical signs. (Dan) Fascinating work. I always enjoy listening to toxicology cases. (Steve) We get all the crazy ones. We are actually one of the few diagnostic labs with a toxicology section in the Midwest. We get a wide variety of cases from really all over US and even international cases. Toxicology at Iowa State is always very interesting. (Dan) Yes, it’s a great service. If you have a toxicology issue, this is the man to send it to. We’re going to take a break. We’ll come back and wrap up toxicology with Dr. Steve Ensley here at Iowa State University.

(Dan) Hey folks. Welcome back to DocTalk. Dr. Dan Thomson here with Dr. Steve Ensley who’s a Veterinary Toxicologist and the Section Head of the Veterinary Toxicology here at Iowa State University’s College of Veterinary Medicine. When we bring people on the show, they’re very busy. Dr. Ensley is no exception to that rule. But to get the opportunity, thank you so much for spending time with us. (Steve) Yes, I like the opportunity because toxicology is probably the most interesting part of Veterinary Medicine. [Laughter] The more we can talk about it, the better it is. (Dan) It is interesting as long as it’s happening on somebody else’s place, not mine. There are some things that you’re seeing here with trace minerals and vitamins. There’s been a shift though from not having enough to having too much. (Steve) Right, so we have some really good products. They’ve been introduced to the market, well used. If they’re used correctly, we see no issues. Supplementation is or deficiencies have been an issue and continue to be an issue with copper, selenium, vitamin A, vitamin E. We still see those as issues, so we need to supplement usually. If we over supplement, that’s where we also become involved. We’ve got a machine that we use that can measure a variety of trace minerals at one time. We also look at vitamin A, vitamin E consistently. Some of the issue is not just the deficiencies that we normally look at but the potential overuse, because there’s several products especially if they’re used together, mineral supplementation that we see issues with. They’re good products, just like any product, when they are not used correctly that’s when toxicology becomes involved. One thing, we do a lot of liver biopsies. We look at a lot of trace minerals in livers. For copper, really, liver is the only tissue that really tells you what that status is. Serum just won’t. In fact serum is usually, whatever the serum level is, the liver level will be the opposite of that. We get a lot of confusing findings when we’re trying to use serum to determine metabolic issues in animals. (Dan) I hear a lot of times they say you don’t measure the — We measured the level of gas in the gas tank, not the fuel line. (Steve) Exactly. Serum tells you what the diet’s been in the last seven days. Liver will tell you what it’s been in the last 30 days. That’s really what we want to know. What’s the diet been over a period of time, because if you make any significant diet changes, it shows up in the serum pretty quickly and doesn’t really tell us sometimes what the real nutritional status is. (Dan) You work with your local practitioner to get some sort of feel on that? (Steve) Right. We see depending on where you’re at in the US, there’s a lot of regional differences in mineral availabilities or mineral toxicities. Your local practitioner, again, is the key. We work with them. They get the samples we need and we can communicate with them, and help make sure that we don’t have problems with the animal. Nutrition is huge. (Dan) Thanks for being on the show today. Thank you for watching DocTalk. Remember to always work with your local practitioner. If you want to know more about what we do on DocTalk, you can find us on the web at Thanks for watching us today. I’m Dr. Dan Thomson at Iowa State University and I’ll see you down the road.

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