Sorry, long post!
My two Himalayans came down with ringworm right after we got them, they were 14 weeks old. We were able to clear the ringworm without medication, it is doable but takes some work. It takes several weeks to clear with or without medication and protecting the environment so they don't get it again is important. My vet does both Western and alternative medicine so we worked up a plan to make it as safe as possible. Here are the things we did (we also had a dog that was dying of stomach cancer and could not be treated, she never got it). Where are the spots, this makes a difference in how it is treated also. Mine had it on the ear, mouth and under the eye so there was limited stuff we could use.
For the environment we got some stuff called Health Guard Laundry Additive & Disinfectant from Revival Animal Health. I used it weekly in the laundry for my family as well as pet bedding. I also shampooed the carpet with it and wiped down the furniture. I mopped and sprayed just about everything else, including baseboards, tile etc. with diluted bleach 2-3 x a week. Spraying the heat vents also as it is airborne. I had a mightly clean house for 3 mos!
My vet shaved the areas where the ringworm was. Keeps it from spreading.
I shampooed them with special shampoo from the vet, can't remember how many times a week. They hated that!
She got me some purified castor oil capsules from a local chiropractor that I rubbed on the sores.
I got a wood lamp and checked all over them and the dog, house , etc. daily.
Yes it is a lot of work but it cleared and it has been 2 years without a new breakout. Even if you use meds treating the environment is half the battle. You can get a lot of information on the internet. No one in my house, human or animal caught it and it never spread. The shampoo and shaving helps conatain it, the disinfecting helps to not get it back and the oil kills it. Good luck, it is worth it.