Deworming Question!!

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Deworming Question!!

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    02-21-2008, 09:10 PM
Deworming Question!!

After you open up a tube, how long can the tube be stored for before it's not good to use anymore?
I have always had to deworm a ton of horses, so I'd buy bulk and usually just end up with a few unused tubes and maybe a partial one, and it never made sense to keep the partial one, so I just chucked it... but now I'm looking at only having one horse of my own to which I will provide all wormings etc for... so I will just need to use part of one tube... I'd rather not throw away a half tube, but will if it's bad to keep for extended periods... any advice?

Also, I've recently heard of switching brands each time you deworm, or rotate them, but not use the same brand twice... I hadn't thought of that before, as I always bought what was in stock at the cheapest rate for the last ranch I worked at (TERRIBLY cheap ranch. Glad I'm gone!!)...

Lastly, what brand do you use?
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    02-21-2008, 10:20 PM
Can't it be refridgerated or something?
    02-21-2008, 10:34 PM
How long it can be kept is going to depend on the expiration date printed on each tube. And you need to store at relatively moderate temperature.

Moxidectin gels don't last long once opened--at least Quest gel doesn't---it tends to liquify and run all over the place if you don't use it within a day or so.

As for rotational deworming and what to use, here's my long-winded idea on that subject and deworming in general. If you want more specific advice on what kind of deworming program suits your situation, answer the questions about the specific situation and I will try to help you work out a program to run by your vet.

A deworming plan depends on lots of variables--age of horses, type of management (stalled vs. pasture vs dry lot), pasture maintenance practices, history of the pasture (have there been horses on the pasture previously), local environmental conditions. Some horses only need to be dewormed once or twice a year while others require a much more stringent deworming program. Once these variables are known, then you can formulate a deworming plan that fits the situation. It's always best to contact your vet to discuss these issues however we can help you lay out a plan and then you can run it by your vet.
Rotating dewormers is an old plan that was necessary back when the drugs we had available where not broad spectrum--one might get ascarids, another strongyles, etc--so rotation was done so that you were treating for all the different types of parasites. Then it was continued once we got better drugs available for deworming even though it's not necessary to be able to target the different parasites but in the hopes of preventing the parasites becoming resistant to the drugs. However, this has not been the case and with the situation we are now in there is very little "room" for rotating drugs (which in fact means rotating classes of drugs not just brands or chemicals) because the benzimendizole class (fenbendazole-Safeguard, Panacur, etc) is of very little use because of resistance issues in 95% of the world, and the pyrantel paste (Strongid, Equicide, Rotectin, Strongyle Care) has resistance issues in around 50% of the areas where it is used. The avermectins (moxidectin and ivermectin) are the only class of dewormer that doesn't currently have any resistance issues in strongyles which is the main issue in adult horses (though ivermectin resistant ascarids have been seen in certain areas and this is an issue for foals). So, rotation options are limited at best and it's really not the rotation that is most important for preventing parasite resistance but appropriate dosing and treatment intervals.

You need to be SURE you are not under dosing your horses so always use a weight tape or measure your horse and calculate his weight. In studies even many vets were way off on weight estimations and they have the benefit of spending a few years working in situations where they get to walk horses onto scales daily to see what 900 lbs LOOKS LIKE.

Weight calculation information:
Body Weight Estimation of Horses KG calculation shown as well as a chart based upon heart girth measure (remember, the heart girth only assessment may be off by as much as 200 lbs just like weight tapes)
Horse Weight: Estimate It Easily How to calculate in pounds

As for appropriate dosing intervals, you want to treat according to the egg reappearance period so that you are dosing to prevent continual recontamination of your pastures. This method means that you will be cutting back on your horse's risk of parasite infestation significantly after a year appropriate dewormings because you will have cut the number of parasite larva on your pastures. It also means that you won't be deworming at a time when there are no parasites in the system that will be susceptible to the product you are using next which happens if you dose too soon after ivermectin or moxidectin with pyrantel or fenbendazole because at normal doses these two chemicals only kill adults in the GI tract and if you've dewormed with moxidectin last 8 weeks ago there aren't adults there to kill and you've missed the migrating larva which will then start shedding eggs 4 weeks after you treat with either of these drugs and shed for the 4 weeks until you deworm again. Or if you dewormed with ivermectin 6 weeks ago and treat with either pyrantel or fenbendazole you will start seeing egg shedding into your pasture in 2 weeks because you didn't have adults in the GI tract when you dewormed last but they will be there in a couple of weeks. Or in the case where you actually do have adults for the pyrantel or fenbendazole (which again is not likely to be working) to affect because it's been 8 weeks since your last dose of ivermectin you will again have parasite ova being shed in 4 weeks because that is how long after the use of either of those drugs you start seeing adult egg shedding parasites in the GI tract. So deworming based upon Egg Reappearance Periods, you would deworm and then deworm again based upon what drug you used last--4 weeks later for pyrantel (or Fenbendazole, though the next day would probably be more useful LOL), 8 weeks after ivermectin or 12 weeks after moxidectin. In this manner, you can significantly reduce the parasite load on your pastures in a year's time.

Deworming every 6-8 weeks routinely and rotating products is also not the best way to go. Again, we need to focus on appropriate use of the deworming products we have to help prevent the development of parasite resistance and blindly deworming every 6-8 weeks no matter what product you last used doesn't take into account how long it is until you actually have parasites that are capable of shedding eggs again.

Besides deworming, there are pasture maintenance practices that can help to minimize pasture contamination with parasite larva. Rotating pastures with other types of livestock (cattle, sheep, goats) can allow time for the parasite larva to die off before you put horses back on it but you have to have many months between rotations. Picking up feces at least every 2-3 days will also greatly reduce the parasite load on your pastures. (Doing this daily will keep the amount of feces you have to shovel at one time down ) Dragging pastures to break up feces during the very hot, dry southern summers will also help lower parasite burden on pastures, but if you do it during moderate weather it will only help to spread the larva around.

Whatever deworming information you read, make sure it's up-to-date. Many articles and recommendations are based upon old information and that can lead to wasting money and providing poor parasite control for your horses.
    02-21-2008, 10:37 PM
Honestly, I have no idea any information would be appreciated!

Edit: this reply was to Blu's post... Ryle and I posted at the same time haha!
    02-21-2008, 11:08 PM
1. How old is your horse?
2. Is your horse stalled all the time or turned out? If turned out, is it pasture or dry lot?
3. Do you pick up feces every 2-3 days in your horse's turnout?
4. Are there other horses turned out with yours? If so, are they dewormed regularly?
5. What are the general weather conditions in summer and winter? Extreme heat or cold for prolonged periods?
    02-21-2008, 11:21 PM
Hey Ryle, have I mentioned how great it is to have you on this forum?

Here are my answers:

1. How old is your horse?
Not sure, don't own it yet. It will be young, could be from a weanling up to a few years old... I'll let you know details as soon as I purchase one!
2. Is your horse stalled all the time or turned out? If turned out, is it pasture or dry lot?
24/7 turnout on a pasture
3. Do you pick up feces every 2-3 days in your horse's turnout?
I don't believe I will be doing that if it's run with the other horses, then no, the pasture is very very large. If it's kept in a smaller pen, then I will probably be going through whenever I can to pick up manure.
4. Are there other horses turned out with yours? If so, are they dewormed regularly?
If it's turned out with the other horses, then yes it will be with other horses, but I might opt to keep it in another pen close to other horses so it doesn't have separation issues. Regardless, I'm not sure what kind of a schedule they have the horses on.. I would defeinitely find out, and if they don't even know (they're your typical acreage owners) then I'll offer to do their horses at the same time as mine.
5. What are the general weather conditions in summer and winter? Extreme heat or cold for prolonged periods?
I live in southern Alberta, which is very dry no matter what season it is. Normal summer temperatures range from 20-30 degrees Celcius but can spike to 40+ degrees for a couple of weeks at a time. Winters are pretty mild for the most part, but are very dry. We do have our cold snaps that can sink down to -40 degrees Celcius or lower with wind chill that can last for a couple of weeks then it will warm up. We also have chinooks in my area....

I hope this helps! Thanks again, Ryle!!
    02-21-2008, 11:37 PM
Yeh I can imagine they would go off, taking the cap off, it is exposed to moisture. I only have 3 horses atm, so I just buy 3 wormers (from where I work...Stockfeed and horse specialist).

Lastly, what brand do you use?
I do Rotate. I use Equimax LV, and then to rotate I use Ammo (which is a Australian brand) and I have had no problems
    02-21-2008, 11:41 PM
Well, the specifics are going to be really important in setting up a deworming program. A weanling is going to need more frequent deworming than a horse that is over a year old. A horse in turnout with other horses is in a pasture that isn't picked up and where the other deworming schedules are unknown or vary is going to generally need more frequent deworming than a horse that is stalled or dry lotted or kept in a paddock alone that is picked every couple of days.

When you pick a sure to deworm it with either ivermectin or moxidectin (if it's over 6 months old) prior to bringing it to your place. This will help keep pasture contamination down where you are by cutting out egg-shedding in your new horse before it arrives.
If you get a horse under 1 year of age, it's generally recommended to deworm monthly until it reachs a year of age-rotate ivermectin and pyrantel for that. Then put it on a normal "adult" schedule.

For adults in a pasture setting with other horses who's deworming you have no control over---a daily dewormer, deworming regularly or deworm based upon fecal egg counts.

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