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Are parasites becoming resistant to dewormers?

My cows don't get a de-wormer anymore. Calves get it in the spring and then in the fall after a killing frost. I've been taking the training wheels off the animals as best I can to start selecting for a better herd that will thrive on low inputs. When I do de-worm, I use cydectin to help with my dung beetles which are thriving in my pastures.

I listened to a guy talk who was an expert on parasites, he basically said we need to stop using the dewomers so much, use only as needed and breed for resistance, because we'll likely never develop anything again that is as effective as the Ivermectin family.
 
Ben H said:
My cows don't get a de-wormer anymore. Calves get it in the spring and then in the fall after a killing frost. I've been taking the training wheels off the animals as best I can to start selecting for a better herd that will thrive on low inputs. When I do de-worm, I use cydectin to help with my dung beetles which are thriving in my pastures.

I listened to a guy talk who was an expert on parasites, he basically said we need to stop using the dewomers so much, use only as needed and breed for resistance, because we'll likely never develop anything again that is as effective as the Ivermectin family.
Click to expand...
Selecting for resistance works...treating growing animals for parasites pays...don't confuse the two by keeping treated animals for breeding...regardless of how good they look!!!
 
One of the most important criteria for my decision to use native cattle, was the resistance to both internal and external parasites, this trait in the herd coupled with a well planned grazing rotation eliminated the need to use expensive de wormers and pour on 'dips', the resistance to parasite bourne diseases reduced the costs of vaccinations.
 
It's amazing what selecton can do-we used to be jack the bear on footrot-till an oldtimer told me you can treat it and it will be better in two weeks or leave it and it will be better in fourteen days'. Were having a bit opf a wet year and some is showing up but all but one case is in new cattle we brought in-they're shaking it off on their own. Healthy cattle can deal with alot of lifes little tribulations.
 
I figure cattle had tens of thousands of years to become parasite resistant and they didn't do it. It seems to me that those that don't have parasite problems can thank their neighbours for treating their cattle.
 
Silver said:
I figure cattle had tens of thousands of years to become parasite resistant and they didn't do it. It seems to me that those that don't have parasite problems can thank their neighbours for treating their cattle.
Click to expand...

As I don't care for crawly things wandering over my body I won't expect the cattle in my care to put up with them either. :wink:
 
This depends what part of the country one lives and how much rain and how short they graze cattle. I would not be suprised if cattle from a arrid west never need it. However a cattle trader has been purchasing cattle from Kentucky, Tenn and the Carloinas (yep those cattle stop here for a sort and rest on there journey to the feeding states) those cattle are wormed three times every two weeks and use different wormers each time. While their are changing their addresses
Way many people here have gotten lazy using the cheapest pour on year after year. And they are cheap. Not many run them though a chute just try to get them at feeding.. So there is alot of cattle they think get a worm when it actually hits somewhere on the cow. I figure those are about 70 percent good IF applied right. Last year I used a high dollar injectable and the cows really improved. I had used cheap pour on for a couple of years and that stuff will catch up to you and you wil not realize it. Used pour on Cydestion sp this year cows are actually fat the past two years. Where the three years of the gerenic the cattle looked thin as so where the calves..
I was raised in eastern Wyoming and we never knew what wormers. And minerals o ya we need some. Here its a second lanugage sp
 
gcreekrch said:
Silver said:
I figure cattle had tens of thousands of years to become parasite resistant and they didn't do it. It seems to me that those that don't have parasite problems can thank their neighbours for treating their cattle.
Click to expand...

As I don't care for crawly things wandering over my body I won't expect the cattle in my care to put up with them either. :wink:
Click to expand...

The native breeds have been developed from cattle which according to archaelogical evidence, took 3000 years to migrate from Egypt to the southern African bushveld, traveling through the most inhospitable terrain for cattle, in the world. A further 2000 years of selection in te big game country they were selected in, resulted in adaped cattle wich could cope with parasites and diseases harboured by Cape Buffalo, Wildebees and other local antelope species.
As my neighbours were mostly private game reserves and a native reserve, it was they who harboured the parasites and diseases.
The ranches at a higher altitude which ran exotics, had to dose for worms twice a year, dip for ticks every two weeks in organophosphates for the various local tick species, which were on the treated exotics in far larger numbers than on untreated native breeds. Exotics also need to be vaccinated against local tick bourne diseases such as Babesiasis, Anaplasmosis and heartwater, which the local breeds are resistant to.
A big saving in time and finance, and no problems with the increasingly resistant ticks and intestinal worms.
 
If they can breed sheep to be parasite resistant (Katahdin Hair Sheep), then why can't they do the same with cattle? Once these parasites are resistant to ivermectin, then what are you going to do? Like I said before, Scientists don't foresee any "breakthrough" in a replacement for Ivermectins, nothing as effective.
 
The way I see it is I can do the best I can with what I have to help the cattle develop more resistance to parasites. I'm well aware though that resistant means just that - they can resist, although they are not untouchable. There may still be years where the cattle actually rub themselves raw here and there. We haven't used Ivomec or any such product for 9 years and haven't seen it yet, but I am not ruling out the possibility.

Anyone who spends any amount of time in the out of doors - and pays attention - will notice times when the moose are hairless from ticks and the deer are scruffy as a junk yard dog. It happens to the best of them, so it's bound to happen to cows as well at times.

I still see no reason to use a chemical solution on our place. The cattle can thrive just fine in the right conditions without it, and if there comes a time when we see them suffering, we'll deal with it. I'm not going to let animals suffer just for the sake of being able to brag about being all natural. However, I am going to keep bragging about how the resistance is growing in our cattle. :wink:

This sounds like the mob-grazing thread though - it all comes down to personal preference and to each their own. :wink: I can agree to disagree with anyone. :lol:
 
Someone posted something on here a while back about people using ivermectin at 1/5 the labeled rate just to control lice. Well, what do you think that does to the other parasites that it doesn't kill?

And then you have the people who read on the five liter bottle that it will treat 100 1100 pound cows. So they make sure that they get 100 (or more) cows treated with each bottle - even though their cows weigh 1400+.

With practices like those, it should come as no surprise that parasites once controlled by ivermectin would be building up a resistance to it.

I still use the generic ivermectin, but I try to give about 30-50% more than the label calls for. It seems to work well and it's still cheaper than anything else.
 
The only disadvantage to over treating is cost, my Vet said it doesn't hurt them, it's just wasting money. But if you under treat, then you've really wasted your money and may compound the problem.
 
In regards to the 1/5 dose and creating immunity--
I was at a parasite seminar where Dr. Don Bliss of Mid-America
Labs was the featured speaker.

It was a few years ago, but I'll do my best to relate what he
said. The avermectin products--the pour-ons, not the injectibles-
have to pass through the hair, the hide, the fat and get into the
internals. If they started out with an effacy of 18, by the time
the dewormer reached the internals, the effacy could be reduced
by as much as half. That's where the immunity comes from--
the product itself.
Also, when the companies that run the trials and tests with
the avermectin products, they SHAVE the back of the cattle
in order to get optimum results--and those are the results that
are published.

Have you noticed that the Lice guarantee has been taken off the
avermectin products? Like some avermectins for instance, one of
their main selling points was their lice guarantee--
use it and it would control lice for 6 months. That was a bogus claim
and the government made them remove it.
According to Dr. Bliss, the only way to truly
kill lice is to pour them twice. I think within 13-14 days to get the life
cycle of the lice. Lice are easy to kill, 1/5 of a dose will do it, but then
the eggs hatch in 13 days and that's why you must pour them again.
Who wants to do that? So mostly we all get by pouring them once.
Sometimes you will get an outbreak later and will need to do it
again. And again, you should repour them in 14 days. (I could be off
on the days by one or two). But when you get that second break of
lice, we generally comment, "well, that delicer didn't work"...but that's
most likely not the case. It probably did work, only the eggs hatched
later in that 13-14 day period.

Hope this helps.
 
PureCountry said:
The way I see it is I can do the best I can with what I have to help the cattle develop more resistance to parasites. I'm well aware though that resistant means just that - they can resist, although they are not untouchable. There may still be years where the cattle actually rub themselves raw here and there. We haven't used Ivomec or any such product for 9 years and haven't seen it yet, but I am not ruling out the possibility.

Anyone who spends any amount of time in the out of doors - and pays attention - will notice times when the moose are hairless from ticks and the deer are scruffy as a junk yard dog. It happens to the best of them, so it's bound to happen to cows as well at times.

I still see no reason to use a chemical solution on our place. The cattle can thrive just fine in the right conditions without it, and if there comes a time when we see them suffering, we'll deal with it. I'm not going to let animals suffer just for the sake of being able to brag about being all natural. However, I am going to keep bragging about how the resistance is growing in our cattle. :wink:

This sounds like the mob-grazing thread though - it all comes down to personal preference and to each their own. :wink: I can agree to disagree with anyone. :lol:
Click to expand...

I think Steve Kenyon is treating parasites with apple cider vinegar or some such thing...seems to work for him.
 
Some claim to get results with Diatomaceous Earth as well, although there are reports that it kills dung beetles also. It's tiny edges are so sharp that it cuts up the wings/bodies of insects, or so I've been told. I've thought about the AC Vinegar, haven't gotten around to it yet.
 
Faster horses said:
In regards to the 1/5 dose and creating immunity--
I was at a parasite seminar where Dr. Don Bliss of Mid-America
Labs was the featured speaker.

It was a few years ago, but I'll do my best to relate what he
said. The avermectin products--the pour-ons, not the injectibles-
have to pass through the hair, the hide, the fat and get into the
internals. If they started out with an effacy of 18, by the time
the dewormer reached the internals, the effacy could be reduced
by as much as half. That's where the immunity comes from--
the product itself.
Also, when the companies that run the trials and tests with
the avermectin products, they SHAVE the back of the cattle
in order to get optimum results--and those are the results that
are published.

Have you noticed that the Lice guarantee has been taken off the
avermectin products? Like some avermectins for instance, one of
their main selling points was their lice guarantee--
use it and it would control lice for 6 months. That was a bogus claim
and the government made them remove it.
According to Dr. Bliss, the only way to truly
kill lice is to pour them twice. I think within 13-14 days to get the life
cycle of the lice. Lice are easy to kill, 1/5 of a dose will do it, but then
the eggs hatch in 13 days and that's why you must pour them again.
Who wants to do that? So mostly we all get by pouring them once.
Sometimes you will get an outbreak later and will need to do it
again. And again, you should repour them in 14 days. (I could be off
on the days by one or two). But when you get that second break of
lice, we generally comment, "well, that delicer didn't work"...but that's
most likely not the case. It probably did work, only the eggs hatched
later in that 13-14 day period.

Hope this helps.
Click to expand...

When you use 1/5 dose the second time 13-14 days later, you are only compounding the problems with the internal parasites (that the product is also labeled for) that aren't killed by the product. The same thing is often done in fly country in the south - using smaller than labeled doses of ivermectin just to control horn flies. The internal parasites aren't controlled by those rates, so it only makes them more resistant to the product.

Something very similar happens with antimicrobials. For example, Draxxin is a very expensive product to use for metaphylactic purposes. So, some people decided that they could use less of it and still get acceptable results. That works for a short while before organisms start developing an immunity to it because of underdosing. And then, before you know it, we have lost another good product because it is no longer effective.

Whether we want to admit it or not, one of the reasons for resistance to products is poor management and failure to follow the label.
 

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