Capstar tablets by Novartis Animal Health are a rapid action oral treatment that kills fleas on dogs and cats, using Nitenpyram as the active ingredient. Capstar begins working within 30 minutes of ingestion and will kill more than 90% of adult fleas within four hours on dogs, and six hours on cats. One dose (a single tablet) of Capstar will kill all the adult fleas that are present on your pet, and if reinfestation occurs, it is safe to administer another dose (as often as one tablet per day). Capstar is a 'no mess' flea treatment; as the tablets are ingested orally there is no mess or odour through application and cannot be rubbed or washed off the skin. Capstar tablets are safe to use in dogs and cats over the age of four weeks. Use only as directed on the label. Please note that your pet may be temporarily restless and scratch after ingestion as a result of fleas dying.