For fleas, bathe your chihuahua in raw apple cider vinegar and see if that helps. Also put some in a spray bottle and spray her several times a day.
Also, a mixture of brewer’s yeast and garlic, available in powder or tablet form, can be given in small doses. This creates an odor which fleas avoid.
Luella
Sorry I didn't see this post earlier. Put one teaspoon in your chihuahua's water. Or you may want to put it over her food.
You can spray the apple cider vinegar direcly. Any sores should dry up within 24 hours.
Luella
Actually there are a a great many instances of colloidal silver being being effectve against giardia - as you can see with a Google search for (giardia and colloidal silver) particularly when given in large doses at night and the left in the drinking water the rest of the day. My own suggestion wouold be to comgine the silfer with a good parasite cleases,
Tony