Colloidal Silver for dogs?

Alright, so I have had my dog for a total of 7 years, I adopted him when he was 2. 2 years after I got him he started to get ill...about 6 vets, 5 different diet changes and more than $6000 later, he is still sick. I did some experimenting (since no one can seem to help him) and took him off all of the medications he was prescribed and he is doing so much better. He has more energy, his eyes are brighter, his fur is growing back in and he actually gets out of his comfy bed to "socialize". So, I'm thinking that it's an auto-immune issue or an over active oil gland issue (I have to bath him twice a week and his skin is almost greasy (and VERY stinky). I was going to start with the first with all natural medications like Colloidal Silver (an immune system booster) and Olive leaf extract (a natural anti-biotic) Now, I've taken it before because I used to have chronic bronchitis and colds and I've gotten so much better so I do believe that it works, the one thing that I can not find out from my vet or the doctor who suggested it to me is...Is it safe to give to my dog? Does anyone know anything about this? Thanks for any help!