Treating lung worms in goats

I've got 3 pregnant does, the older 2 have been coughing for weeks with mucous in their nostrils.
I'm just realizing it's likely lung worms. They've been treated with Ivermectin already this Spring. First time using chemical wormer on them. They're on good forage and getting moved around. Due to kid in 3 weeks. What are some suggestions for treating this lung worm? Preferably natural and most effective.

Do you supplement them with minerals?

Copper is one that makes them more resilient to all kinds of internal parasites, but there is an upper limit for it, so some care is needed not to feed too much.

Vitamin C helps with all kinds of goat ailments. Garlic is also a good thing to feed against worms. Kelp is something that helps goats to absorb many trace minerals that they need, but if you live somewhere when high selenium in the soil, then some care might be needed on this one. Dolomite can help too.

I give them copper boluses about twice a year and free choice Redmond's trace minerals. Also selenium and probiotic paste about once a month.
Haven't given kelp - that is a very good idea. I will get some soon. Mixed up some herbal garlicy stuff for them yesterday to help.  
I've never experienced my goats coughing like this. I'm very unfamiliar with lungworm and worried about it.

Just a reminder... don't worm them until they kid. I feed mine Black Walnut leaves. They can kill a horse but goats love them. Most conifers are a natural wormer, along with raw pumpkin seed and psyllium. Fieasco Goat Farm sells a good natural wormer as does Hoggers. http://hoeggerfarmyard.com/

Other plants high in tannins will also help with worming, such as oak, grape leaves, birdsfoot trefoil.

I like to use homeopathics with my goats.

I use Cina 30C mixed with Teurium 200C for parasites. I just put one dose of each in their fresh water daily.

Good for lungs as well is Kali carbonicum 200C. You can put one dose in some water and either use a syringe to squirt it some in their mouth. Give twice a day.

If they have nasal drainage as well, I'm wondering if they might have something like a sinus infection?  I use Hepar sulph 200C mixed with Sanguanaria 200C for sinus infections. Again dissolve one dose of each in water and squirt it into their mouth twice a day.

One of the awesome things about homeopathy is that the same remedies will work for people or any of the other farm animals. Pretty amazing stuff.

I order my remedies online. I like www.abchomeopathy.com

Penny