Ivomec Timing Question

[ladyveg]

I´m giving all the pigs in my house 3 doses of Ivomec. No one´s showing problems, but I took in 8 pretty sorry-looking pigs in December, complete with spots of thinning hair. Since it doesn´t hurt to give a pig Ivomec even if it doesn´t have mites, I decided to just get everyone while I´m at it to make sure the new pigs don´t pass them around (yes, I quarantine).

So I did the first dose on 12/23. I know the 10- to 14-day mark would have been Jan. 2 to Jan. 6, but I didn´t do the second dose until Jan. 9. I will surely do the third dose between Jan. 19 and Jan. 23, but will I have to then count that as a second dose instead of a third? In other words, since I waited 17 days in between the first and second dose, do I have to start all over?

I think I did a full Ivomec party (where all pigs got 3 doses) twice last year, once in April/May and once in the fall. With so many different critters coming and going, I feel better treating them every now and then in case someone has a problem I´m not catching.

[Lynx]

I think it´s up to you. Three doses will probably work fine. I´ve seen recommendations from repeating the second dose (usually only two are mentioned) from 7 to 14 days after the first. I usually do 10 days. It actually depends on what critter they have, as the life cycle varies from one kind of bug to another.

[ladyveg]

What I mean is, I know 7-14 days is correct, but is 17 days too long to be effective?

[Lynx]

I´m sure it will do something. Your risk is that a crop of parasites hatches (ivermectin does not kill eggs) and matures enough to lay their own eggs. So it depends on the particular life cycle of the parasites they have.

If you are giving your second and third doses within 14 days, that will probably take care of them.

[Evangeline]

I treat everyone twice a year, too, just to be on the safe side.

[kleenmama]

double post.

[kleenmama]

If you are concerned about the time lapse, you can dose them a 4th time. This is why it´s important, like Lynx said.
Ivermectin does not kill lice eggs. So if after 3 days, new lice hatch, then the second dose kills them before they lay more eggs. And the third dose makes sure nothing new has hatched. With a 17 day lapse, they might have hatched AND layed more eggs.
So if you are concerned, just use the second dose date as the first. On particularly stubborn mites, I´ve had to dose pigs a fourth time anyway. Doesn´t seem to hurt them.