Hi I have a 10 week old cavalier King Charles spaniel. My vet recommended a liquid applied to the neck to control heartworm, fleas, ticks and intestinal worms. I looked up this product online and there seemed to be a lot of reactions to this product and to other flea products applied this way. I feel more comfortable with ingested tablets after researching online so I've gone out and bought heartgard and Drontal because the heartgard doesn't protect against all intestinal worms. The problem is there's a crossover of some of the ingredients making timing difficult as I don't want to overdose him. What brands and combinations of treatments have people found effective and safe. Do I really need to flea my dog all the time?