Jack,Originally Posted by CA Jack
I noticed you recommend 2x daily worming with febendazole. I have searched everywhere for this dosage and I'm unable to locate it. Could you please share your source for this?
I've only used this product once daily for 3 days or from day 40 until 2 days post delivery with pregnant bitches. Your dosage would be more convenient if there is benefit in dosing this way.
Thank you,
S_B
Yes. Just look at the Merck Veterinary Manual, says BID, which means twice daily
Jack
That's where I looked...
"When neonatal pups die due to hookworm infection, subsequent litters from the bitch should be treated weekly for*A caninum*for ~12 wk beginning at 2 wk of age. In addition, fenbendazole (25 mg/kg, PO) given daily to pregnant bitches from day 40 of pregnancy to day 2 after whelping greatly reduces transmammary transmission to the pups (approved in the UK). Likewise, treatment of the bitch with ivermectin (0.5 mg/kg) on two occasions (4–9 days before whelping and 10 days later), or with moxidectin/imidacloprid spot-on on day 56 of pregnancy, has the same effect (extra-label use)"
Link: http://www.merckmanuals.com/vet/dige...0animal&alt=sh
Link: http://www.merckmanuals.com/vet/dige....html#v4720080
Jack for some reason last night I could not pull up that picture. I see now where it says BID, it also says "divided dose" and then goes on to say in pregnant bitches 40 days - 14 days blah blah.
Maybe I'm being dense but it is still a bit unclear.
The divided dose throws me off, do you take the dosage split it in half and give twice?
S_B
It's very simple.
All divided dosages are given in exact time frames, divided precisely throughout the day, as opposed to willy-nilly, based on half-life.
BID = 2x/day = every 12 hours
TID = 3x/day = every 8 hours
QID = 4x/day = every 6 hours
Etc.
Yes, it goes on to mention special consideration for pregnant bitches, to deal with worms in the muscle, for which NO medicine works, which worms get periodically released due to the hormone changes in pregnancy (you have to read other sections of the book to get that part). This is why ALL pups need such frequent worming as well ... their mama is constantly releasing worms, which not only get transferred transplacentally, but also via the milk.
The Merck Manual Online used to have the BID part clearly stated, but apparently they changed their website around, and whoever put it together omitted the BID part (which is why I always have a physical copy of the book).
It is also easy to understand WHY fenbendazole is given so frequently when you read about the drug in general, understand how it works, what it's for, and when you also understand the digestive tracts of which animals it's being given to
#1 Fenbendazole is a very weak drug, designed for ruminants.
Ruminants have the longest digestive tracts of any animals, and so the medicine stays in there longer, giving longer exposure to the worms.
By contrast, dogs have very short digestive tracts, and the medicine is in and out of them in a hurry, reducing the exposure time to the worms.
Because fenbendazole is such a weak drug, and because it is in-and-out of a dog so fast with one dose, and because of resistance in worms, the dosage was changed in fenbendazole from SID to BID several years ago. Many labels still don't reflect this change, but the change has been made, IFF one stays on top of the literature and reads all the reasons why.
If you still want to keep giving SID, that is up to you.
But I suggest you buy the physical Merck Veterinary Manual and go through it carefully.
Hope this helps.
Jack
I have the physical, I'll dig it out. The divided still has me cocking my head, the single dose divided into two doses given on each day, or the single dose given twice each day?
Thank you for taking the time to give a very detailed answer. I appreciate it and I'm sure others do too!
There is no mention of "divided" in the book, except for the 50 mg/kg divided BID from day 40 to day 14 of gestation.
My Merck is the Ninth Edition 50th Anniversary Edition published in 2005. Which one do you have Jack?
Interesting. I have the same one. (We both need to upgrade!)
You got that from page 356 I reckon, although you didn't actually post the page, while I posted the page I got mine from.
Thus it looks like a contradiction in the Merck Manual itself
All I know is, based on the other surrounding facts I mentioned above, the new elevated dose, the fact the drug is known to be weak to worms unless they're exposed to it for a long time (while you can give 100x the dose to a dog with no ill effect) ... I will continue using it BID and you can continue using it SID
Jack
Jack you are correct I posted pg. 356
I think we are just interpreting the dosage differently, or the book is contradicting?
I found the section you posted "Anthelmintics" and read over "Benzimidazoles" which is the class of drug febendazole is considered. It states that febendazole is a prodrug because it has a longer half-life, it is not rapidly metabolized into an inactive product. Then goes on to point out what you stated above about the digestive system of a ruminate or horse. (I know I'm stating the obvious here, and you know this!)
I'm not trying to disprove what you say at all Jack, but I would like this to be clear for myself. It is matter of using twice as much drug at twice the cost.
I found this article about febendazole dosage in dogs I thought I'd share. Link: http://wildpro.twycrosszoo.org/S/00C...nbendazole.htm
S_B
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