PetTest Colloidal Silver Spray serves as a natural external antibiotic for dogs. They help fight a wide variety of infections, such as yeast infections and skin rashes. However, that's not all. You'll find that colloidal silver also tends to have anti-fungal, antiseptic, and disinfectant properties. The silver ions present in the solution easily penetrate molecules and destroy pathogens of all kinds, such as parasites, viruses, fungi, and bacteria. When you treat your pet with colloidal silver, he is bound to return to his best self within a matter of days.