Thoughts on giving canine Credelio a week early?

August 19, 2023 6:12 AM

Our dog is about to spend a week in a tick-tastic environment, at the end of which his monthly oral flea/tick medication is due. Should we give him this month’s dose before the trip instead?

Hugo is on monthly oral Credelio for flea/tick prevention, and last got it July 27th. This Tuesday we’re going on vacation and bringing him to a countryside camp where he will basically be romping outdoors with friends for 6 days (we did this last year and by all verbal and audiovisual accounts he loved it)—returning on the 28th. We’re thinking about giving the Credelio this Sunday instead for maximal tick protection. (Last year we asked about using a Seresto collar and they said they don’t recommend them because they tend to come off and get lost during the romping.)

He is current on Lyme vaccine, and as seen in the photo we got him a shorter trim than usual for easier detection, yet he remains a curly black-haired dog. I’m sure the vet would say to keep to the schedule, and it appears Credelio has been studied for effectiveness up to 35 days, but it does seem like it would offer more protection toward the beginning of a dosing cycle, and that perhaps there’s nothing magical about 30 days in terms of safety.

What would the dog owners of AskMe do?

posted by staggernation to Pets & Animals (3 answers total)

Best answer: From their website: In a well-controlled laboratory study, Credelio started to kill ticks (Ixodes ricinus) within 4 hours of administration, with 98.7% of ticks killed within 8 hours. Credelio has a sustained speed-of-kill throughout the month and is effective against newly acquired Ixodes ricinus ticks within 8 hours, with an efficacy of 94.3% when measured at 7, 14, 21 and 28 days post-treatment. At 12 hours after infestation, lotilaner sustained effectiveness of at least 94.2% up to day 35 after treatment.

So, it starts out at 98.7% effective, and is at least 94.3% effective at 28 days, 94.2% at 35 days. So yes, it does decrease in effectiveness a bit, but it's still very effective. I would not worry about the slight difference.

This sounds similar to the heartworm medication for my cats, which my vet mentioned is technically good for a bit beyond what it says on the box, but that pet medications tend to be somewhat conservative.
posted by coffeecat at 7:09 AM on August 19, 2023 [2 favorites]

Best answer: According to The intravenous and oral pharmacokinetics of lotilaner in dogs, the active ingredient in Credelio has a half-life of about 30 days.

So if Hugo has been on a regular monthly dose, then at the end of any given month he's still going to be carrying half that month's initial dose, plus a quarter of the previous month's dose, plus an eighth of the dose from the month before that and so on, which works out pretty damn close to what he'd have had on board right after his very first dose.

If he were my dog, I wouldn't worry about him not having enough Credelio in his system and I wouldn't bring his next dose forward.
posted by flabdablet at 7:30 AM on August 19, 2023 [3 favorites]

Best answer: No, it's fine. I live in a tick area, we spend some time in the woods, I think we use Simparico, I often give it a week or so late, she's tick-free, which means she doesn't deliver ticks to me; I have to get them on my own. (I got agricultural permethrin, use a dilute solution on a set of clothing and socks.)

Hugo has a distinguished air; is that Viscount Hugo, by any chance?
posted by theora55 at 7:59 AM on August 19, 2023 [1 favorite]