(Dan) Hey folks, welcome to Doc Talk. Dr. Dan Thomson here. Glad you joined us today. We’re gonna have a great show. Dr. Deon van der Merwe is going to be with us, talking about blue green algae and some of the things that we can understand more about this problem and some of the things you can do to prevent it. Thanks for joining us and stay tuned for the show.
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(Dan) Deon, welcome to the show. (Deon) Thanks very much. (Dan) Folks this is Dr. Deon van der Merwe and he is an associate professor here in the Diagnostic Laboratory at Kansas State University and he is the head of our Toxicology Section and you’ve done a lot of work with this blue green algae and it’s a pretty serious problem that we have here in the U.S. and specifically around our area. (Deon) It is. It’s definitely, actually it’s world wide. So it’s a problem all over the world where we have open water, open fresh water. And especially when we have conditions where the temperatures can get fairly high in the summer. (Dan) Yep. (Deon) And then coupled with that if you have the nutrients available in the water that can allow these organisms to multiply rapidly; that’s when we see the real problem. (Dan) Yes, it’s one of the those things that every summer, you know, you sit there, you’re going to your favorite lake and all of sudden it says, “We’re Closed.” (Deon) Exactly. (Dan) And it can happen in the ponds and it can happen in many different areas. (Deon) And it’s a really challenging problem. The reason is that we are… as human beings multiply, we are obliged to provide food. So, we really don’t have a choice but to use a lot of nutrients for crop production. And arguably that is the biggest source of the nutrients that eventually makes its way into lakes and cause the triggering of these blooms. So it’s a Catch 22 situation. We are really forced to use nutrients to produce food. But in that process, we unfortunately have these potential negative consequences including harmful algae blooms. The harmful algae blooms are really… it’s just normal organisms that are part of the ecology of any lake. In fact, if you go and look at any lake, even if there is no bloom, and you really fine comb the organisms, if you look for them, you will probably find cyanobacteria there. But they are just normal background constituents. In many ecosystems they are very important, primary producers. So they produce the initial food for other organisms to build onto that. So you have eventually fish, so the whole production of a normal ecosystem is also dependent on these organisms being there. (Dan) Right. (Deon) So, just being there is not a problem. It’s really when we have too much nutrients, coupled with things like a lot of light available. So, if you have conditions in the summer, the heat wave conditions, so you have many days of cloudless weather, very hot, that tends to promote the growth of these organisms. (Dan) So, these bacteria, these anti-bacteria are present in the lakes, they’re part of the normal ecosystem but when we have an increase in the supply of nutrients coming into the lakes or ponds, through fertilizer and things to that nature, increased sunlight, increased heat… (Deon) Right. (Dan) So, when we see these blooms. (Deon) And on top of that, one of the reasons actually why we are seeing an increase is that we are changing the landscape. So if you compare let’s say the Midwest landscape from many years ago there were many fewer open water bodies. We create small water bodies, ponds for livestock and lakes for recreation, and water management and so on. And these create opportunities for the organism to cause a problem when the conditions are right. (Dan) Very good. Well folks, we’re gonna take a break. When we come back, more with Dr. van der Merwe and talking about blue green algae. Thanks for joining us.
(Dan) Hey folks, welcome back to Doc Talk. Dr. Dan Thomson here with Dr. Deon van der Merwe and we’re talking about blue green algae. And Deon when we left we had kind of set it up. We’ve got more bodies of water. We have to produce more food for more human beings. So, we’re putting more fertilizer, more nutrients on. It’s winding up in our water supply. It’s causing this bloom. And so now these bacteria are always there and we just helped create the situation. But let’s talk a little bit about some of the different problems. Cause when they shut down the lake, or they shut down the thing, it’s something that people outside of agriculture… well everybody that uses the lake inside or outside agriculture wants to know more about why we’re not going in there, or why our dog got sick, or things to that nature. So, let’s talk a little bit about these different products. (Deon) OK. And something I should maybe point out is that if you look at the economic impact of the problem, a lot of it is associated with things other than direct poisoning. But it’s the need to avoid poisoning that adds a significant economic impact. (Dan) Sure. (Deon) So when you have conditions that might lead to poisoning, so you have risky conditions, then we have to take action. We have to close lakes. Farmers need to provide alternative water sources for livestock, etc., etc. So, it really is a wide economic footprint if you think of all the implications of conditions that lead to risk. But if we focus for a moment then on the poisoning itself, one of the most common types of toxins that are produced by cyanobacteria, and I have to also say that there are a variety of toxins. So not all cyanobacteria blooms are going to produce the same kind of poisoning. But one of the most common, especially in our region, is caused by a toxin called microcystin. Which is produced by a number of cyanobacterial organisms, but the most common source is microcystis is a species of cyanobacteria. And when I first got interested in this problem, it was because of a very severe bloom of microcystis that happened in Milford Lake here just west of Manhattan. And it caused poisoning and death in dogs that visited the lake. There were also some cases of human poisoning, luckily not very serious, not lethal. But that really sparked the interest because that showed how rapidly lethal these toxins could be. These dogs when they visited the lake and they ingested the material, they would typically die within a couple of days of the ingestion. Very, very serious rapidly developing disease due to liver failure. So, it’s a toxin that at first, so the first exposure that they get, tends to cause a rapid, inflammatory response. So it causes an irritating effect on things like mucous membranes. So, if you get some of that contaminated water in your eye or so, you’ll probably experience an irritating effect. So tearing and inflammation and pain. But then you will also, if you ingest it, it will cause vomiting and diarrhea and then you get liver failure after that if the dose is high enough. (Dan) Well, let’s take a break. And when we come back, we’ll wrap up on the liver and go to some of the neurotoxins. You’re watching Doc Talk and we’re sure glad you joined us.
(Dan) Welcome back to Doc Talk. Dr. Dan Thomson here with Dr. Deon van der Merwe. And he is the head of the Toxicology section here at Kansas State University’s College of Veterinary Medicine. Done a lot of research on blue green algae. It’s something that we go to a lot of seminars on and a lot of talk about blue green algae with respect to the livestock industry-our horses, our dogs, many different animals. You know, we talked about liver toxins, but what about neurotoxins. (Deon) Yea, that’s the another group of toxins. So the liver toxins are very important but probably the second most important if you look at the impact on the number of cases we are seeing, are some of the neurotoxic substances that are produced by cyanobacteria. Specifically anatoxin; there are two types of anatoxin A and anatoxin AS. These are quite similar in effect, but they are different toxins. The anatoxin A is very similar in its effect to nicotine, so if a person were to ingest nicotine, the effects that you see associated with that, which are neurologic. It affects the musculoskeletal system in the sense that those nerves that go to those muscles become affected. And at the junction between the nerve and the muscle there are receptors that will be affected as well. So, the control of the muscle becomes abnormal. So, what you see there is that initially you will see muscle contractions, abnormal uncoordinated muscle contractions. And if the condition persists, then the muscle will become paralyzed. So very often… (Dan) Good grief. (Deon)…we see these cases, animals will just be found dead or they might be found in that initial stage where they have lots of muscle contractions so the animal might be convulsing, things like that. But it acts very fast. In fact anatoxin A’s original name was Very Fast Death Factor. And they came up with that name because when they injected mice with an extract of this algae scum the mice would be dead in a few minutes. So they just call it Very Fast Death Factor. Later on when they described the structure and so on and they figured out more exactly what it was, they called it anatoxin, anatoxin A specifically. (Dan) So you know with both the neurotoxin and the liver toxin, this is pretty rapid as far as… and what species does it…? (Deon) That’s a good question. It’s actually very indiscriminate in terms of species. So it will affect livestock. It will affect pets, people, wildlife, birds, even fish. So if fish are swimming in a lake where there are high concentrations of the toxins, and they are not able to avoid those high concentrations, fish might actually die. Also if you look at bio markers or poisoning and you look at fish that are caught in a lake that if affected, you will typically see bio markers that indicate that there is a physiological effect in those fish. So, it’s very indiscriminate, if you look at the mechanism of action it is those substances in the cells that are affected are present in all cells, all living cells. So, the reason that we get serious effects in some species rather than others, more related to their exposure, how they ingest, do they get enough of those poisonings? (Dan) Perfect. We’re gonna take a break folks. When we come back, we’ll wrap up on blue green algae. You’re watching Doc Talk We’re glad you joined us.
(Dan) Hey folks, welcome back to Doc Talk. Dan Thomson here with Dr. Deon van der Merwe. And we’re talking about blue green algae and you know one of the things that kind of struck me is, OK so I walk out into my pasture, what am I looking for as a producer, beef producer to make sure that I don’t have blue green algae or if I do how do I diagnose it in the pond? (Deon) Right. So, I am assuming that you’re talking about the situation where livestock have access to a pond and they use that as a water source? (Dan) Absolutely. (Deon) Which is very common. In many cases it’s the only available water source, so if you have to have alternatives, it’s very expensive and inconvenient to have to provide that. But if you have a pond, the first thing that you typically will expect to see is a change in the color of the water. So most cases, the color will change to green. And it can be that the organisms are growing in the water column. So below the surface. And then just the general color of the water will turn into a different color. (Dan) OK. (Deon) Usually green, but sometimes it can be brownish or reddish as well. (Dan) OK. (Deon) It’s kind of more or less of a bluish tinge to it. So, it’s variable. Just a change in color is a danger sign. And then it can be that they algae bloom will form a scum that floats on the surface which is quite common, but it’s not always the case. But very often it is. So some of the common organisms like the microcystis, that we get in this area, tend to float to the surface. And because they float to the surface and if there is a breeze that blows across the surface, they tend to blow along the water surface and accumulate on the down wind side of the pond. So, if you have a pond and you see what can be called an algae scum or an accumulation of blue or blue green or brownish material on the down wind side, that is definitely a danger sign. And if you see that the best thing to do is to not allow animals access until you verify what that’s caused by. (Dan) So grab a sample, send it in to the Diagnostic Lab; they can tell you if you have it. What can I do in my pond if I do have it? (Deon) If you have it, what you can do depends very much on the type of pond and the circumstances. So if it’s a small pond then you have more options to do things. (Dan) And what are those? (Deon) So, there are chemicals that you can add to the water, things like copper will effectively kill the organisms. So, if you have a serious bloom and you need to break that bloom, that is an option if the conditions are right. So, if you can safely apply chemicals like that, then it might be an option. You have to keep in mind though that it’s not a permanent solution. It’s only going to kill those organisms that are there at the time. But they can bloom again, if the conditions don’t change. You can also do things that will interrupt the requirements of the organisms. So things like interrupting sunlight. There are things that you can add to the water that will essentially shade the water to prevent sunlight from penetrating. You can also plant tall trees around the pond to limit sunlight. If you have a lot of water plants in and around the water, that competes for nutrients with these organisms. So that can reduce the incidents as well. So there are lots of different things that can be used to try and prevent the problem from reoccurring. (Dan) Perfect. Thanks for joining me today. (Deon) You’re welcome. (Dan) And thanks for joining us today on Doc Talk. Remember always work with your local veterinarian and if you want to know more about what Dr. Deon and I do here at K-State you can find us on the web at www.vet.ksu.edu. I’m Dr. Dan Thomson. Thanks for watching Doc Talk. And I’ll see you down the road.
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