Lice on goats, what to do?

[goats&sheep19]

So, my mum and dad got angora goats over 20 years ago. (before I was around)
We never really did much with the hair, and for most of those years they have just been pets. For as long as I can remember, they have had lice.
My dad just thinks it is natural to have some, and not really a problem. (and we have never had any real health problems caused by them, as far as I know) but I can't help but think it must be so uncomfortable for them.
We have tried giving them Ivermectin of the kind that you put on their necks, and while it did kill them, they came back. (maybe we missed one?) I then tried dusting them with Permethrin at weekly intervals, but think I missed some lice, as again they came back.
The nearest other goats are about a 1km away, so I think they have just been there ever since we first got them.
Any thoughts one what I can to?

Also, I am thinking of getting some sheep. I have read that lice are species specific, so that shouldn't be a problem?
Thank you for your time and thoughts!

 

[Baymule]

Never had this problem.
@Mini Horses
@frustratedearthmother
@rachels.haven

 

[goats&sheep19]

Any thoughts anyone?
Its not too much of a problem in summer, but in winter they really take off. And of cause, that is when they have the most hair, and can't be shorn.

 

[canesisters]

How big are they?
Can you 'dip' them like sheep? I think it was on here somewhere that I saw a video of sheep jumping into a trough sort of thing filled with some sort of insecticide?
When I worked at a groomers, we did flea & tick 'dip' in the tub all the time. With the dogs it was poured on, then thoroughly splashed & soaked into all the underparts so not even a bit of webbing between toes was missed.

 

[Ridgetop]

Since summer is coming, try shearing them and then dipping or washing with lice shampoo. Also, giving an oral dose of Ivermectin may be better than just rubbing it on.

 

[frustratedearthmother]

Lice: What They Are and How to Control Them | NC State Extension Publications

Information on the different types of lice, diagnosis and treatment is presented in this factsheet. Lice are a common group of ectoparasitic insects of goats; infested animals are uncomfortable and often cause structural damage to farm facilities by rubbing and scratching on fences and posts.

content.ces.ncsu.edu

 

[Mini Horses]

You need to disinfect the premises. Repeat worming meds as those hatching after first worming need to die....it takes some effort to get them under control.

 

[Show Sebright]

ivermectin 1cc every 50 lbs, given in mouth. Worked great

 

[goats&sheep19]

Thanks everyone for all the ideas!
@Show Sebright is it the same ivermectin that is sold as pour on for cattle that you give by mouth?

 

[Mini Horses]

Not pour on by mouth. Injectable liquid, yes. Paste, yes.