- Give your pets the very best. Sovereign Silver Bio-Active Silver Hydrosol, certified by the National Animal Supplement Council (NASC), provides daily immune support and allergy relief for pets. It works by promoting the body’s natural resistance to pathogens. Pets love it’s neutral taste (like water!) and pet parents love the weight-specific dosing instructions.A Natural WonderSilver has been used for over 2,400 years to promote health. It’s part of the natural world around us, and even part of