K9 Advantix® II does not expire.Click to see full answer. Also know, how long does k9 Advantix last?K9 Advantix® II kills fleas within 12 hours. New fleas that jump on the dog from the surroundings, such as grass, carpet and pet bedding, are killed within 2 hours with protection against further infestation for at least 4 weeks.Subsequently, question is, does flea and tick medicine expire? No, Zodiac® Spot On® Flea & Tick Control products do not carry expiration dates. Our products will remain effective long after their date of manufacture when they are stored according to label directions. Additionally, does advantage have an expiration date? There is no expiration date required on the packaging by the EPA for Advantage® II for cats. We recommend the product should be kept in its original packaging and stored as directed on the label.How long after applying k9 Advantix can I touch my dog?Avoid petting the dog for several hours after application, as you may wipe the product off the skin.