Ivomec INJECTABLE cannot be mixed with water. Ivermectin POUR-ON can, but I have never seen a good published (backed by research) dose.
Safeguard (not ivermectin) can be mixed with water.
I know that's what the prior poster meant, but since the two brand names were getting mixed up I wanted to make it clear.
The -zoles (fenbendazole, albendazole - marketed as Panacur, Safeguard, Valbazen, and a few other brands) are safe broad-spectrum dewormers that will kill everything but tapeworm and are poorly absorbed by the chicken. Since most of the medicine stays in the gut you can even eat the eggs if you don't mind getting a tiny trace of human-safe wormer in them (don't sell them, obviously).
The dosage of the -zoles varies depending on the active ingredient and the brand (goat, sheep, dog, etc.). Make sure you don't get mixed up between them. I think pretty much all of them are water-soluble, though.
The -ectins (ivermectin, selamectin, moxidectin, marketed as ivomec and zimectrin and Quest and several others) is a very broad everything-killer, effective against worms and mites in mammals and birds. The bad news is that the reason it has such a broad action is that it's absorbed readily into the plasma and tissues of the animal that touches it, including people. It'll get into your eggs, the meat, and so on, and will medicate you if you get it on your skin. Withdrawal periods are very important if you use them, and if you're worried about your own exposure use gloves. The -ectins have varying reports of effectiveness in chickens depending on how they're given (injectable, oral, etc.) and are not necessarily great at doing a good deworming. The published research shows that the medication in ivomec injectable, which is what most people buy at the feed store, isn't very good until you get up to an oral dose close to the toxic level of the medication. Works very, very well on mites, though.
Injectable ivomec is sitting in a glycol base. That means it won't mix well with water. If you're using it orally you need to either give it straight, if you've been given a dosage by your vet, or mix it with another glycol or glycerine or something thick like karo syrup that will hold it in suspension. If you're using it topically for mites, you can open the plumage and drip it on the bird and the glycol should spread it through the oil production under the feathers. Dripping it on the bird won't worm the bird, though.
