I used it to cure my white leghorns of an intestinal parasite.
Anything in large enough quantities is toxic, even water, but, if used the way it has been used (and documented since the 700's BC), it works very well and is safe.
I use 2 oz of 25 ppm colloidal silver solution mixed with a pint of filtered (brita) tap water.
It can also be applied as a topical. Most burn centers use colloidal silver as part of the treatment of sever burns.Military bandages use colloidal silver because it works and doesn't die at high or low temperatures.
Do not ingest silver nitrate or other compounds. They can be toxic. In small doses, they are effective. They use silver nitrate drops in baby's eyes to prevent bacterial blindness.