Is Trifexis a good flea medicine? Trifexis is approved by the FDA as safe and effective when used according to the label. Spinosad, one of the active ingredients in Trifexis, began to kill fleas on dogs 30 minutes after administration with 100% effectiveness within 4 hours in a well-controlled laboratory study.
Can my dog still get fleas with Trifexis? Your dog can continue to be exposed to fleas that live in the environment. When fleas jump onto and bite your dog, they will be killed by Trifexis. If, within a month after your dog receives Trifexis, you see fleas on your dog, they are most likely new fleas.
Can I buy Trifexis over the counter? Since Trifexis includes a heartworm preventative, it requires a prescription from your veterinarian.
How long before Trifexis kills fleas? Begins killing fleas in 30 minutes after ingestion, kills 100% of adult fleas in 4 hours. Must be given with a meal. In addition to providing excellent flea control, Trifexis™ prevents heartworm infection and protects again roundworms, hookworms and whipworms.