If you give your pup a little bit of ACV in with his kibble...like around 1/8 tsp once a day, then this will keep fleas as well as ticks away too. Also, I give my dogs 1 tblsn of coconut oil everyday. Coconut oil is a natural dewormer because it has antiviral, antibacterial and antiparasitic properties. My dogs are 4 yo and 5 yo and they go to the dog park and socialize a lot with other dogs and never had had a problem with fleas, worms etc. I don't deworm them or use the flea protection and have never had a problem with fleas or anything else since I've started this protocol with them about 2 years ago.
Also, if you know you're going into a flea/tick infested area then mix a spray bottle equal parts of ACV and water and spray you pup down. It stinks a little at first, but the odor disappears fast and you have instant healthy proctection...plus it conditions the coat!