Colloidal silver in your dog's water is the best preventative against infection. This is a natural antibiotic that is effective in killing over 650 pathogens, even those that have now become resistant to our modern antibiotics.
I, too, do not frequent a vet because I do not believe in vaccines or antibiotics. Colloidal silver has healed all my pets' conditions and is responsible for healing my friend's puppy from parvo. Now, I just have Misty and I give her colloidal silver every day as a preventative. She is nine years old now, happy, healthy, and has the disposition of a puppy.