Quest Plus vs Equimax

[sportyspicepony]

Hi, I know there are a lot of similar topics on here about this question but mine is slightly different.

My horse is new to me and I had her fecal egg count done and it came back astronomically high - 1425 eggs / gram

The vet told me on the phone to use EITHER Quest Plus or Equimax to deworm her now, then send another fecal sample back in four weeks. I think giving her Quest Plus would be super risky with that high of a parasitic load, wouldn’t it? Is there any reason to be in a rush to give her the Quest Plus right now vs. just starting with the Equimax and then re-assessing after the next fecal exam?

I’m wondering why the vet would tell me either option is fine when one comes with a risk of colic and one doesn’t… My barn owner and the vet both suggested giving her a dose of banamine with the Quest Plus, but to me, that doesn’t fix the root of the problem which would be an impaction?? I already told the BO I want to do the Equimax because I’d rather just not risk it, but I’m just wondering if there’s any reason why that wouldn’t be the safer option. I tried calling the vet back to ask these questions but they haven’t called me back yet!

[candyappy]

If you feel that strongly about Quest Plus being risky, just give the Equimax as per your vet. I never heard of any issues with Quest and colic or ( impaction colic). One is Moxidectin vs Ivermectin and both have the praziquantel so it must be that?

Is she severely underweight due to high worm load? That is what can make deworming risky as far as I know.

[sportyspicepony]

My concern is just that her count is soooo crazy high! If you search for advice about deworming a horse that has a high parasitic load, that’s something that always comes up.

She’s not severely underweight, I knew she probably had a high count because she has a big belly but seems to have lost a little bit of weight in the past month. But even with the research I’ve done online, I haven’t seen anyone yet with a count even close to 1425! Isn’t that super concerningly high?

I guess I’m just worried about whether it’s more important to kill the worms now since there’s SOO many or to be wary of killing them too fast, since the moxidectin will kill the encysted small strongyles and ivermectin/praziquantel won’t.

[Posting_Trot]

Quest works differently than some of the older wormers. It causes them to die in place, and so it’s less likely to cause an impaction colic than some of the older wormers might have. The manufacturer only suggests that you not use Quest in very thin or debilitated horses or in young foals.

The big advantage of Quest over ivermectin is that it kills encysted strongyles as well as adult worms, which is helpful if your horse has a high worm load.

I think if you’re concerned you should talk to your vet about the risks and the benefits.

[sportyspicepony]

Yes just patiently waiting for the vet to call me back now!

[Equkelly]

I’ve never had a problem with quest plus and I’ve never heard the increased colic risk thing. I only use it for years when they horses get bommed with botfly eggs though.

I will say if your worried about increasing your colic risk I would want to get that parasite situation under control now. Idk about quest plus increasing your risk for colic but a high parasite load absolutely does.

[WildLittleWren]

I once saved a filly who was so severely skinny that we weren’t sure if she could get herself up on the trailer and stay up on the ride home (only a 15 minute drive). I had the vet meet me at my house. We had her assessed, and when her fecal worm count came back later that day it was a 2,550 worm count. She said it was the highest number she had ever seen.

We were able to deworm safely and bring her back to health. I forget the worming regimen we did, however, if you are uncomfortable with the Quest, I would start with the Equimax and then follow up with another fecal. Then discuss it with your vet to determine next steps.

[sportyspicepony]

Spoke to the vet again and they were basically like, do whichever option you’re most comfortable with!

For those who say they’ve never heard of the scenario of a horse having an impaction after being wormed for the first time in awhile with a stronger product like Quest Plus, here’s some links to bring you on the anxiety train with me!

https://blog.smartpakequine.com/2011/07/safely-deworming-with-a-heavy-parasite-load/

New Horse hasnt been wormed in AGES!!

Horses in Colic Impaction Colic What causes colic

Ascarid Worm Impaction

[JB]

@sportyspicepony

My horse is new to me and I had her fecal egg count done and it came back astronomically high - 1425 eggs / gram

I had one out of the blue with 1500. I used Quest Plus

@sportyspicepony

then send another fecal sample back in four weeks

4 weeks isn’t a good time. You need to do that 10-14 days after to check efficacy, OR, 4 weeks after the “good for” time, which is 8 weeks for ivermectin, 12 weeks for moxidectin, which means 12 or 16 weeks respectively

@sportyspicepony

Is there any reason to be in a rush to give her the Quest Plus right now vs. just starting with the Equimax and then re-assessing after the next fecal exam?

Equimax will get everything QP will, except for encysted strongyles which you aren’t seeing in the FEC anyway. You could do Equimax now and re-test in 12 weeks, or do QP now and re-test in 16 weeks - Spring.

@sportyspicepony

I’m wondering why the vet would tell me either option is fine when one comes with a risk of colic and one doesn’t…

They both have a risk of colic. The risk isn’t likely terribly high.

What’s the horse’s deworming history?

[sportyspicepony]

@JB I’ve only had her for like a month and a half so I’m not sure… and the owners before me had only had her since April and it was basically a situation where they bought the horse and immediately sent her to a trainer to sell, so it’s possible they didn’t do anything at all wormer wise.

My vet was the one who suggested a re-test in four weeks, but I’ve definitely seen/read stuff with the timelines you’re referring to. I guess I can just take another sample back to them whenever I want, so I probably will do 10-14 days!

[JB]

A vet suggesting a 4 week re-count isn’t a vet I’d look to for deworming advice

If you want to be cautious, an option is double dose Strongid to kill tapeworms, and some level of adult strongyles. Then in 2 weeks use Quest Plus to finish off the rest. That’s faster than iver-moxi, a bit safer due to 1) pyrantel pamoate not killing bots or encysted strongyles and 2) pp likely being not terribly effective against adult strongyles though it COULD be, but you still won’t kill bots/tapes/encysted, so still lowering the kill numbers.

[sportyspicepony]

Ohhh okay interesting! So you think it’s just as risky to use ivermectin as moxidectin? Would banamine be a solution to reducing the risk for either of those? I don’t really understand why they suggested banamine as a way to make it safer…

[JB]

Inflammation is a factor in both the existence of parasites, and in killing them. That may be why the banamine.

Since you don’t know the level of encysted strongyles, you don’t know how much of an impact QP will make over Equimax.

[jlm0305]

@sportyspicepony

I haven’t seen anyone yet with a count even close to 1425! Isn’t that super concerningly high?

No. It’s not. Fecal egg count does not correlate to parasite burden in horses. All that number tells you is that your horse is contributing a bunch of eggs to larval burden on pasture, not that your horse has a ton of parasites. I routinely see horses with 2000+ epg, and did a study where a couple horses had FECs in the 3500 range.

Four weeks is not the recommended timeline for a fecal egg count reduction test. It is two weeks - this is what AAEP recommends and it is what we do in all of our research for anthelmintic efficacy. This is really important because both moxidectin and ivermectin are losing efficacy and the egg reappearance period for both is different now from what it was when the drugs were still introduced. If you want to check for reappearance of parasites post-deworming rather then efficacy, you’d want to check at about 8 weeks for ivermectin and 12 weeks for moxidectin - that is what the estimated efficacy is now. If you still don’t see anything, check again at about 13 weeks for ivermectin and 22 weeks for moxidectin; these are the labeled efficacy times. I will reiterate that even if you see more eggs at these times, it has nothing to do with the overall burden of your horse; horses will always have parasites unless kept in highly sterile conditions as they are constantly reinfecting themselves via feces.

Here are a couple useful sources of information:
AAEP
Deworming and Inflammation

[sportyspicepony]

Thank you for all this info! I’m fascinated by this stuff, stressful as it is; I’m wondering where we’d be if we just left the relationship between horses and microbial organisms alone to begin with

[jlm0305]

No problem!

@sportyspicepony

For those who say they’ve never heard of the scenario of a horse having an impaction after being wormed for the first time in awhile with a stronger product like Quest Plus, here’s some links to bring you on the anxiety train with me!

Impaction colic is only really a concern in juvenile horses or horses that you suspect of having ascarid infections, and it is extremely rare. Just as an example, we routinely work with very large thoroughbred farms (think 90+ foals per year) on the parasite control programs, and the farm managers all either say they’ve never had a foal with impaction colic due to ascarids, or maybe have had one or two in 15+ years. That is how rare it is. I can’t even imagine the number of small strongyles it would take to make a parasite wad big enough to cause an impaction - it would be quite impressive!

The main culprit of parasite-induced colic was Stronglyus vulgaris, a large strongyle that is virtually non-existent in modern managed horses. It doesn’t cause impaction colic, but rather thrombo-embolic colic, where a blood clot due to the parasite living in the cranial mesenteric artery causes issues. Anthelmintics are still highly effective against large strongyles as well, unlike the cyathostomins. We don’t really know why, but it’s certainly interesting and worth studying at some point!

[sportyspicepony]

Very interesting… My horse is 11, so hopefully that’s not a problem for her. This AAEP resource is super helpful, it’s hard to find stuff online that isn’t published by some company that has something to gain from it!

[RedHorses]

When my horse had a load of encysted small strongyles that were causing irritation in his hindgut my vet had me do an initial kill with something else, then fecal check again two weeks after to confirm the active worms were reduced prior to going after the encysted load with Quest. This was almost ten years ago and I can’t remember which drug was used for the initial active kill (though I’m sure it wasn’t ivermectin).

My understanding of the initial kill was the affect the load of dead worms would have on the gut bacteria population as dying bacteria can produce toxins which affect the horse. My horse didn’t need that at the same time as his intestinal walls were expelling dead encysted worms.

[JB]

@jlm0305

horses will always have parasites

And we need them to maintain a small population to keep the immune system stimulated, at least for the ones they can develop immunity to

@RedHorses

When my horse had a load of encysted small strongyles that were causing irritation in his hindgut my vet had me do an initial kill with something else,

How was that load of EL determined? You can’t “see” them.

@RedHorses

My understanding of the initial kill was the affect the load of dead worms would have on the gut bacteria population as dying bacteria can produce toxins which affect the horse. My horse didn’t need that at the same time as his intestinal walls were expelling dead encysted worms.

this is a good read on the inflammation deal
Researchers Assess Deworming’s Link to Inflammation in Horses – The Horse

Note this comment:

“In large numbers they can cause a rare, life-threatening disease called larval cyathostominosis—a mass eruption of encysted larvae that leads to a profound inflammatory response in the horse’s gastrointestinal tract.”

Cyathostominosis can also be caused by a Power Pack because of how it targets the encysted larva. This is a UK article
Diagnosis and treatment of cyathostominosis in horses (vettimes.co.uk)
but it says:

" however, where it [fenbendazole] is effective its use is actually likely to result in a greater intestinal inflammatory response than moxidectin31."

[RedHorses]

@JB Sure you can. It’s called a hindgut biopsy.