Is it true that fleas are becoming resistant to Frontline Plus for dogs? This is a question that is often asked on many online pet forums and blogs these days. Could it be that this famous pet flea remedy is no longer as effective as it used to be? Or perhaps pet owners are not using it correctly and then blaming the product? Even cat lovers are getting in on the act. On one well known cat forum a pet owner recently mentioned that she had asked for a refund after buying Frontline Plus for cats online. She claimed that…