Thursday, April 23, 2015

Horse deworming the German way

I've spoken with my vet about worming schedules and thought I understood wrong, but today I found a paper written by a vet clinic that recommends what he said.

Here in Germany you worm with one type of wormer 3 or 4 times yearly, and then rotate to the next type of wormer the next year. In America we worm with one type of wormer per season (if I may generalize) and rotate to the next wormer for the next season. I like the yearly packs that give you four tubes for the year, all different types. I just looked and in the Netherlands you can buy a yearly pack, but it's 4 of the same thing (with Praziquantal in one of them). I can't buy wormer online in Germany, because here you have to get it from a vet (like if you need Tylenol you must go to a pharmacy and ask for it).

I've run into this problem before: I walk into the horsey vet office and ask for Benzimidazole  and they say they don't have any and they won't be ordering it. (I always refer to the active ingredient because I'm unfamiliar with German trade names.)

So I called my vet today and asked for Benzimidazoleand they said, "We don't carry that this year. This year we only carry Pyrantel." No kidding, this is reality?

My burning question is, who is correct? One way must be advantageous. If you do it the German way, your horse only gets Ivermectin every 3 years. In my mind, if you give one type of wormer, and then 3 months later, the same thing, and then 3 months later, the same thing again, you have created resistance. I guess I'm ignorant about how resistance works.

The paper also stated the importance of keeping the horse stalled 3 days after worming, to prevent the eggs from re-entering the horse. This leads me to ask if the wormer causes the expulsion of eggs, are the eggs still viable?

I emailed S to ask what protocol she follows. I was shocked to hear her answer, "I don't know, the vet comes out twice yearly and worms the horses. I don't know what it is." I was shocked because she is meticulous with his care (He coughed once, one cough, and she drove to the vet and got him lung medicine. She sifts his hay portions every day with a pitchfork to remove dust, then soaks it. She removes manure from his stall daily with her hands (with gloves on). My vet calls her vet "Dr. Money.")

Anyway, I'm fascinated by the "judicious use of toxins" to minimize parasites, and I wish I understood more.

7 comments:

Christie said...

What I am starting to do is fecal egg counts and then treating only when the eggs are a certain level. Usually only two does in the year total for a low shedder. http://www.thehorse.com/articles/26861/implementing-a-deworming-program-based-on-fecal-egg-counts-aaep-2010 Can you get fecal egg counts in Germany?

Bakersfield Dressage said...

Ooh ... this is a FAVORITE topic of mine. My vet has a protocol based on where we live - dry, hot climate. We do fecal counts twice a year: once in teh spring once it has warmed up, and then in the late fall or early winter when we've had something close to a frost.

If teh test is negative, mine always are, I deworm with an ivermectin product in the spring, and an ivermectin gold product (with the added ingredient praziquantel) in the fall.

If teh count comes back positive, which it did with Izzy the first time, I give a second dewormer (based on for what he came up positive) followed by another fecal count to be sure we cleared up teh infestation.

There's a lot of new research out there that suggests rotating just creates resistance. In fact, some research is suggesting that a low parasite load might actually be beneficial. When a horse carries a low parasite load, he's not as "reactive" when there is an infestation. in other words, teh body learns to cope with a parasite load.

Since my climate is so dry, we never have a positive count. Now that Izzy has been with me for a while, I fully expect his spring EPG to be negative. Even with a negative count, we still give an ivermectin product as encysted strongyles don't show up on fecal counts. Ivermectin still takes care of that problem.

For horses on green pasture, my vet recommends more frequent fecal counts and then de-wormer based on the type of worms detected.

My vet pointed out that most of the research American vets use is based on what is happening in Kentucky, horse capital of the USA. Since the climate in central CA is so different from the wetter climate of Kentucky, modifications have to me made.

Keep us posted!

lytha said...

Christie, We can do fecal egg counts here, and I've done them. But I'm one of those paranoid people who think that they won't show certain types, or at certain times, so I opt to worm more often. But less often than in America, where I was worming every 6-8 weeks (!!).

Karen, Does your climate influence the success of worm eggs surviving on your fields? I never thought about that. I think it's interesting that climate can affect our protocols.

When you say rotating creates resistance, I am surprised - I'd always learned that rotating prevents it. I need to learn more.

You mentioned that ivermectin works against encysted strongyles? Not a simple one day dose....or? I wasn't aware that ivermectin takes care of encysted strongyles, otherwise why would the panacur power packs be so pushed by vets?

Thanks for commenting on this, I'm fascinated by this topic because what we know seems to change so often.

Nuzzling Muzzles said...

When trainers and vets were trying to get me to worm more often, I would keep it between 10 and 12 weeks because I was more worried about resistance build up than anything else. Now my vet is saying no sooner than every 12 weeks or so. I've never followed which type of dewormer should be given based upon the season, but just rotate to something that I didn't give last time. If I had them out to pasture, I might be more diligent about tracking which type of worms I should be nuking.

Bakersfield Dressage said...

Lytha - while I don't have a field, the climate here does impact the availability of eggs to survive. When our horses poop, it lands on dry dirt. We pick it out of our paddocks at least once a day, but even it stayed there for several days, the eggs couldn't survive because the ground is hot and dry. The eggs need moisture to hatch. This is the main reason my horses are always negative when they have a fecal count.

Worming every eight weeks with a different product creates resistance for several reasons: the first is that without a fecal count you are not sure which eggs you are targeting, nor whether you actually eliminated them. Secondly, If you give a worming product and it doesn't kill your intended audience, they have a chance of surviving the product which just creates a resistance.

Numerous studies have shown that many types of worming products are no longer even effective in parts of the US for that very reason. The more people continue to administer those products without checking to see which worms their horses have. the more resistance that will be created.

Dr. Blanton, one of the vets from my hospital (she has since relocated) wrote a great article about worming. You can find it on my website here: http://www.bakersfielddressage.com/educational-items.html You'll have to scroll down just a bit and open the article which is a PDF called "Strategic Deworming."

EvenSong said...

My vet recently told me not to bother with the pyrantel products--they're so mild he only uses them for babies, weak horses, and as a first step with a horse that hSnt been wormed at all for some time (so that the drastic kill off you'd get with ivermectin doesn't affect the horse's system).

Achieve1dream said...

Wow this is all so fascinating! I had no idea rotating created resistances either....