I have 5 horses that I want to treat for encysted strongyles. I do my own FECs (former vet tech) and each of them do need to be dewormed so I figure that I will go ahead and do a powerpak treatment incase there are encysted strongyles. I know the PP and Questplus are the only ones that treated for this but I honestly don’t know which would be better to use.
Questplus is a single dose at $14 x 5= 70. Doing a generic powerpak using liquid fenbendazole would be roughly $120 for a 1000ml bottle that would treat all 5. But which is actually better to use for encysted strongyles? I know they are both effective and I have used Questplus and liquid fenbendazole in the past but I’m not sure which would be better. I know some people have had bad experiences with Questplus but I never have, never even seen a bad reaction during my career, so I am fine with using it. I just wonder if one is more effective than the other…
Fenbendazole gets one more stage of encysteds than moxidectin, but it kills the worms rather than paralyzing them, which is a little harder on the gut.
One isn’t necessarily “better” than the other, but they are a little different. Do you use Quest or Quest Plus in your worming regime with any regularity? Have these horses been power pacd before?
My own personal preference is to power pac horses that are new to me, and then everyone gets Quest Plus in the spring yearly. The power pac is an initial level set, and gets that one additional stage, then we maintain with the Quest. If anyone really was stubbornly unthrifty and encysteds were a possible cause, I’d go back and do another power pac (that hasn’t happened, though.) But hey, your mileage may vary and you may want to approach it differently 
Simkie is right that the PP does kill more, but the stage that moxidectin doesn’t kill would be a small % of the total, so to me, not a significant reason to use a PP over Quest
As she also said, the PP outright kills, which means the dead larva decay in place, and cause ulcerations. Some horses are ok with that, some are not. Moxidectin paralyzes, so they let go and are expelled. That does increase the risk of an impaction, but if the horse has routinely clean or low FECs, then the odds of him having any significant encysted colony is pretty low.
The other issue is the growing resistance of the EL stages to fenbendazole, so a PP might not even be effective enough.
Personally, unless there’s a compelling reason to use a PP, I’d just do the Quest Plus. Then you’re done - adult and nearly all EL stages, bots, tapeworms, etc.
Thanks! I have 2 newer horses in my herd that came in late summer last year and I do not know if they had been PPd but were both done with Equimax prior to coming here, my other 3 have had Questplus last spring, it is my usual go to after FECs or Equimax. But with the horrible rain and erosion we are having here and knowing that everyone is a bit higher than I would like them to be on their FECs, that is why I was considering PPing everyone to start off as a “clean” slate and then do FECs/ERTs in whatever time frame it is depending on which drug I use. (I have the egg reappearance time table in the barn based on which drug is used. Can’t remember it off the top of my head anymore. Damn getting old
A PP doesn’t give you a clean slate though - it won’t kill bots or tapeworms. So you’d still have to come back with Equimax for those.
ERPs:
- ivermectin 8 weeks
- moxidectin 12 weeks
- everything else 4-5
Exactly. One dose/tube of QP is effective against encysted strongyles (supposedly, but see below), bots and tapes. One dose/tube holds strongyle eggs at bay for 84 days. PP is 1 dose/tube for 5 days. Addresses encysted strongyles, but does not address bots or tapes.
HOWEVER, here is a comparison. PP states it addresses 3rd stage and late 3rd and 4th stage encysted strongyles. Quest Plus doesn’t list “3rd stage encysted strongyles”, but it does state it addresses “late 3rd and 4th stage”. So, are some 3rd stage encysted strongyles getting left behind if we use only QP? And does PP not address 5th stage S. vulgaris (arterial), so some are left behind, while QP takes care of them? According to the manufacturer’s labels below, that is the case.
The manufacturer’s literature on PP states:
PANACUR[SUP]®[/SUP] POWER PAC EQUINE DEWORMER (57 G)
Intervet/Merck Animal Health
(fenbendazole)
• EL[SUB]3[/SUB] - encysted (hypobiotic) early third stage small strongyle (cyathostome) larvae (1)
• LL[SUB]3[/SUB]/L[SUB]4[/SUB] - encysted late third stage and fourth stage mucosal cyathostome larvae (2)
• Small strongyles (cyathostomes)
• Large strongyles (Strongylus edentatus, S. equinus, S. vulgaris)
•4th stage S. vulgaris larvae (3)
• Ascarids (Parascaris equorum)
• Pinworms [I](Oxyuris equi)
https://valleyvet.cvpservice.com/pro…/basic/1047342[/I]
And, literature on QP states:
QUEST[SUP]®[/SUP]PLUS GEL
Zoetis
I[/I]
Large Strongyles:
Strongylus vulgaris - (adults and L[SUB]4[/SUB]/L[SUB]5[/SUB] arterial stages) (3)
Strongylus edentatus - (adults and tissue stages)
Triodontophorus brevicauda - (adults)
Triodontophorus serratus - (adults)
[B]Small Strongyles /B:
Cyathostomum spp., including
Cyathostomum catinatum
Cyathostomum pateratum
Cylicostephanus spp., including
Cylicostephanus calicatus
Cylicostephanus goldi
Cylicostephanus longibursatus
Cylicostephanus minutus
Cylicocyclus spp., including
Cylicocyclus insigne
Cylicocyclus leptostomum
Cylicocyclus nassatus
Cylicocyclus radiatus
Coronocyclus spp., including
Coronocyclus coronatus
Coronocyclus labiatus
Coronocyclus labratus
Gyalocephalus capitatus
Petrovinema poculatus
Small Strongyles:
Undifferentiated lumenal larvae
Encysted cyathostomes:
B ??? What, no 3rd stage encysted strongyles? (1)
Late L[SUB]3[/SUB] and L[SUB]4[/SUB] mucosal cyathostome larvae (2)[/B]
Ascarids:
Parascaris equorum - (adults and L[SUB]4[/SUB] larval stages)
Pinworms:
Oxyuris equi - (adults and L[SUB]4[/SUB] larval stages)
Hairworms:
Trichostrongylus axei - (adults)
Large-mouth stomach worms:
Habronema muscae - (adults)
Horse stomach bots:
Gasterophilus intestinalis - (2[SUP]nd[/SUP] and 3[SUP]rd[/SUP] instars)
Gasterophilus nasalis - (3[SUP]rd[/SUP] instars)
Tapeworms:
Anoplocephala perfoliata - (adults)
I know you are considering the official Power Pack product, which is 5 large tubes of fenbendazole. There is also a similar Power Dose product. The 2 just treat up to a slightly different weight horse, I don’t remember which is which.
But to make sure everyone understands, a generic “power pack” is double dosing fenbendazole, by weight. 2.3mg/lb is the normal single dose, and 4.6mg/lb is the double dose. That double dose is also what’s effective against ascarids, fwiw
It just happens that the Power Pack and Power Dose packaged products already come doubled when you are looking at the dial. So if your horse is 1200lb you dial 1200lb, and just for those large tubes, you are giving a double dose.
You can do the exact same thing with normal-sized tubes, but for that 1200lb horse, you need to dial in a total of 2400lb.
And if you have a 1500lb horse, you need more than even 1 tube per day of the PP/PD products.
HOWEVER, here is a comparison. PP states it addresses 3rd stage and late 3rd and 4th stage encysted strongyles. Quest Plus doesn’t list “3rd stage encysted strongyles”, but it does state it addresses “late 3rd and 4th stage”. So, are some 3rd stage encysted strongyles getting left behind if we use only QP?
Correct. But given the spread of the various stages, it’s not something I’d be concerned about, especially in the context of the ulcerations created by dead EL 
And does PP not address 5th stage S. vulgaris (arterial), so some are left behind, while QP takes care of them? According to the manufacturer’s labels below, that is the case.
To my knowledge fenbendazole has never been effective enough against the 5th stage
I always forget about this study. One day it will stick! More reasons to use moxidectin for encysted strongyles:
https://www.sciencedirect.com/science/article/pii/S0304401715300431
The five-day regimen of FBZ achieved 44.6% fecal egg count reduction, had 56.4% activity against luminal adults and larvae, and was 38.6% and 71.2% effective against encysted early third stage (EL3) and late third stage/ fourth stage (LL3/L4) cyathostomin larvae, respectively.
In contrast, MOX provided 99.9% FECR, removed 99.8% of luminal stages, and exhibited 63.6% and 85.2% efficacy against EL3 and LL3/L4 mucosal cyathostomins, respectively.
