Beware of counterfeit dog medications?
This is a warning, not a question. On March 13, 2011's "60 Minutes", there was an expose about the widespread problem of counterfeit prescription drugs manufactured in Asia (mostly India and China) being sold in America and elsewhere. The packaging and pills themselves are often identical to the naked eye, so even pharmacists and physicians would not be suspicious until the medicines fail to work as they should, or cause adverse reactions. Medications manufactured in the USA are not necessarily untainted, either, since the compounds used in their creation are usually imported.
I would caution against buying any veterinary prescription meds being sold online without prescription, and examine packaging for any obvious clues (e.g. misspellings) that the medication isn't genuine. Let your vet know if anything s/he dispenses isn't working.