I'm just curious,Originally Posted by Zissou'sMom
You risk getting watered-down or incorrect dosages from any pharmacy or vet that compounds (mixes) its own medications. However, since flea meds are packaged by the manufacturer I really don't see a problem with it. The problem you run into on-line with these is getting a knock-off or imitation masquerading as the real thing.
Go to a reputable site, and if they do not require a prescription from your vet, then stay away. For instance, Drs Foster and Smith require that you either mail them the original prescription, have the vet's office fax it, or call it in, just like a human pharmacy. Any site that does not do this might not be legit. Any site that offers to have their veterinarians diagnose and prescribe over the internet might not be legit, same goes for people medications.