Podcast: Play in new window | Download | Embed
Subscribe: RSS
Stephen Vantassel here wildlife control consultant bringing you another episode of The Wildlife one to talk today about particular rodenticide it’s not going to be very well known to most of you because if you’re flushing if you’re dealing with pest control because this particular pesticide is only allowed now for use in below ground applications for the specific target pest of pocket gophers. So the product I’m talking about here is Using strychnine for the control of pocket gophers below ground yeah strychnine still around and it’s only allowed in the United States for use on pocket gophers in a below ground application. So but let’s talk a little about strychnine because strychnine is one of the non anticoagulant rodenticides.
The use of non anticoagulant rodenticides for Pocket Gopher Control
There are others out there they’re are not anticoagulant like Bromethalin. zinc phosphide those are active ingredients that are also non anticoagulant. So there is board of the world in anticoagulants although certainly for our industry anticoagulants are going to be the most common rodent aside category that’s going to be used to control pest rodents. So I want to just talk a little about strychnine because while this pest geek podcast in we want to be geeky and we want to learn about things that aren’t there and sometimes outside of our regular everyday activity and it’s not outside of my world because I’m a vertebrate pest specialist.
The Dangers using Strychnine Rodenticide
But anyways I thought it might be interesting because there’s a number of people that get injured by strychnine every year least the least between in the 1980s and 90s and a third of those individuals were actually deliberate consumptions Believe it or not. So people trying to harm themselves which is quite sad. So it just brings to the forefront the importance of making sure that your pesticides are secure because people sometimes want to do bad things with them sometimes to themselves sometimes to other people. So make sure you know where your pesticides are and that they’re secure. And so let’s talk a little little bit about strychnine today. Well as I mentioned it’s a non anticoagulant so that doesn’t cause bleeding in the end.
In fact it’s a powerful convalescent which is just sort of a fancy word meaning that it causes the individual or animal that consumes it to Twitch violently so their muscles they lose control of their muscle activity and they begin to. It’s like they’re having a seizure in there. Seizing violently and that sort of activity is interrupting their ability to breathe. I think you can interrupt their ability their heart activity and so you have this steered their muscles firing all over the place because it’s actually disrupting the normal process of how your nerves are communicating in your body at the chemical level. And so you basically can like asphyxiate because you’re not able to breathe properly and you’re consuming all of this energy and so it’s it’s a pretty ugly way to die.
I believe I remember a picture where an individual that was that consumed strychnine he’ll actually their muscles will. You have the muscles that actually can pull like your bicep and then your triceps. So what happens is they’re extending muscles actually froze in so they were actually arched their body was arched on the ground from a head to the toe with the rest their body was not touching the ground because of their they just went into an extension process so it can be kind of an ugly ugly way to die.
History of Strychnine
Strychnine has been around for a very long time. It was certainly used as far back as 1640 to kill birds cats and dogs in Europe and what they used was were the seeds of a plant where strychnine comes from in the name of the present plant. Is Strychnos nux-vomica which is kind of an interesting name. Strychnos of course is where we get the word strych nine from nux I believe means that night and then vomica Must cause some severe nausea so strict Strychnos nux-vomica is the tree and the seeds contain the active ingredient that we call strychnine. Now this tree is not found in the United States or in North America. It’s actually found in India Northern Australia Sri Lanka and Vietnam. And so this is why sometimes it’s very difficult to get strychnine because if the crop hasn’t if there’s been a problem with the crop in those countries or if there is a labor stoppage or there could be transportation issues so we may have difficulty getting strychnine because of those we can’t source it from here in America.
Now I was told there was one company that was actually looking to import some of the plant and grow it in either the southern U.S. or perhaps Mexico but it just didn’t prove to be economically viable to do that so that didn’t go through because you don’t need a lot of strychnine to get the job done and we’ll talk about some of the LD50s here shortly.
As I said before it’s only allowed presently for use on pocket gophers in a below ground setting though what happens is sometimes people will say well I’m using it below ground but it’s for ground squirrels No no no it has to be both. Both things have to obtain it has to be in a below ground application that means no access to that product you can’t leave the hole open you have to close the hole it has to be only for pocket gophers so if there’s no pocket gophers around you can’t use the product so it’s very restrictive.
That all occurred in 1988 with an EPA decision to stop allowing aboveground use or burrow use that was not closed off in use. And the reason was was because of its concern for probably primary and of course secondary poisoning because there is a secondary poisoning component to this particular product. However the product has been used the active ingredient has been used to kill other animals besides pocket gophers this was prior to 1988. It’s still available I guess you could call me get a special permit.
Things got really really bad because here in Montana prior to 1988 it was actually used strychnine was actually injected in two eggs and those eggs were distributed out in the landscape to kill rabid skunks. There was a rabies epidemic here among skunks and so they wanted to sort of knock that population down out here in Montana and the great plains areas. We have what’s called terrestrial rabies and our primary animal that carries terrestrial rabies skunk We’re back in the east. The primary carrier of terrestrial rabies is actually raccoons. And then you have spill over into skunks. But that’s primarily a raccoon based rabies. Of course bats can have rabies as a general rule in terms of a small part of their population. You want to refer back to the podcast I did on rabies earlier.
Strychnine Mode of Action
So how does it kill. I mentioned before it interrupts the the nervous system of the organism that consumes it causes massive twitching. I’ve spoken to farmers that have used strychnine on ground squirrels and they just say they’re after they eat it. They just come back and see them twitching. The animals are twitching because it causes these powerful muscle contractions in the animal. And so by disrupting those neurotransmitters the animal’s not able to maintain proper homeostasis that means normal a normal life. And so for it dies it’s highly toxic.
Strychnine LD50 lethal Dose 50%
It’s an extraordinarily toxic product. Let’s go over the L.D. 50 you know just to refresh your memory out there perhaps for new new visitors to our podcast L.D. 50 is Lethal Dose 50 percent which means that they find out how much is needed on a milligram per kilogram basis to kill half of the test population. So if you have 20 rats how much product do you need on a milligram per kilogram. So it’s ratio to kill 10 of those rats so not all the rats just 10 so we’re trying to find out how much is necessary and so the researchers found that it takes six point four milligrams per kilogram to kill a male rat. And two point two milligrams per kilogram to kill a female rat in death takes place in less than one hour after exposure. Now remember L.D. 50s are always acute doses these are not chronic doses.
So this is how much does it take in one shot to kill that particular rat. No a rat doesn’t weigh anywhere near two point two pounds as you well know a kilogram is two point two pounds a rat rarely reaches even a pound would you be 16 ounces. So when we say six point four milligrams per kilogram. Well that would be six point four milligrams for probably two point two rats. Right. So are very large rats so B. So it’s going to take a lot less to kill an individual rat because it’s much less than a kilogram to be sure. So it’s highly toxic.
It’s also toxic to other small mammals at very small ratios and it will also kill birds and other organs and kill fish depending on concentrations. But birds Believe it or not require a lot more to kill them. But it will kill them particularly if they’re able to get the treated product directly. There is some concern for secondary poisoning because animals that consume strychnine some of that product will remain in their muscle tissue it’s not like zinc phosphide where it sort of gasses off or if they find the strength. The strychnine product inside their gastrointestinal track then that is also going to be very concentrated. Let me give you some numbers here. When they were doing this study on pocket gophers with strychnine they found that it reached a five point four parts per million.
In the muscle tissue of the pocket gopher. So obviously it’s still remaining even after the pocket go for his dead. But when they tested the gastrointestinal track that’s sort of like the stomach and the intestines. They found thirty five point eight parts per million. So it’s a significantly more slots. Almost seven times six to seven times more strict nine in the gastrointestinal tract. That means the stomach and the intestines when they were analyzing it. So if the animal if one in those pocket gophers reaches the surface of the ground there is a there’s a small risk that it can poison another creature. And if there’s a couple then certainly those that risk increases.
What about the danger to humans on this. Well it doesn’t really seem to have any type of safety problem on the dermal sides. You’re not going to be poisoned through your skin by handling it per say but it can be absorbed through the eyes and certainly when you swallow it course you’re going to be wearing gloves anyways because you don’t want to have that possibility to kill you what they. But the researchers believe and they’re estimating here because obviously we don’t want to be testing on people but they believe that one swallow of an active ingredient bait and by the way the A.I. on the bait is only zero point five percent A.I. active ingredients.
So think about that for a moment. Five one thousandth. Of the product of whatever that one ounce speed is 5:1000 thousands of it. A.I. of strychnine of that one ounce product can kill a 22 pound child one swallow of that. That’s amazing. So you can kind of give you a feel for just how toxic this product is. And this is why you want to be careful. Believe it or not you can obtain this strict nine over the counter in my state of Montana. It’s a general use pesticide particularly at the pound level.
If you’re going into burrow builders actually some of the burrow builder version burrow builder is a mechanical device that allows you to apply toxic baits for pocket gophers over large acreage areas and strychnine is one of those active ingredients that can be used in a burrow builder. You can still buy some of those 35 50 pound bags as a general use product believed believe that so it can be available so why do I mention that.
Because again I want to emphasize the importance of keeping your product under lock and key particularly when you’re using some of these higher toxic products. You should be doing it regardless. But obviously there’s a greater concern for something like strychnine and zink phosphite. Some of these highly acute toxic and it does not take much in someone who has ill will do some very bad things either to himself or others.
Strychnine Is Highly Toxic To Animals
Let me give you a little bit of other information. strychnine is is incredibly toxic on dogs and cats. We’ve had situations I’m aware of situations where people have poisoned horses. People have poisoned dogs and they what they would do is they would take some of this product they would put it into meat and throw it out for the dogs. And that dog’s a goner when he eats that it does not take much at all to do this.
So it is imperative. to be sure that you use this product correctly and accurately and understand that if you have people complaining about you know my dog got sick you may not. They may be looking at you because you’re the pest control operator and they may be thinking that you poison their dog but you have to keep in mind that you may not be the guilty one.
Some of these free ranging dogs travel can travel quite far even in urban areas they can travel over several houses you don’t know where that dog what that dog has been into in there could have been someone who grabbed some of this product that all of the sudden is poisoning poisoning a dog or maybe they were trying to poison something else and the dog ate some bait or a horse ate some bait does not take much at all.
So follow the label keep things safe but I hope you found that information a little bit enlightening even if you’re never going to be dealing with pocket gophers strychnine is a product that’s only allowed for pocket gophers and you may say well why do we still have it that if it’s only for one animal.
Well the reason is strychnine. The research shows of toxic baits that are available. It’s demonstrated to be the most effective. Not by much. but it has always proven to be more effective than any other product but it by a couple of percentage points not a lot. It is more expensive than other products because it has to be imported into the United States from overseas.
However if time is an issue and you don’t have time to keep rebating for pocket gophers and you’re dealing over smaller acreages it may be worth the extra product cost when compared to zink phosphide or some of the anticoagulant baits. Hope you found that at least interesting if not helpful for your business. Be safe out there. Again I’m Steven Van Tassel. Wildlife Control consultant.
Giving you information about the wildlife. Back to you Frank.
