For a monthly heart worm treatment I use Ivomec injection for cattle and swine, given orally at . 1cc per 10lbs , and that is a decimal point in front of the one, so it is one tenth of a cc. I put it on a piece of bread and give it to them. This stuff is the same ingredient as the heart guard you buy at the vet, and the dosage I post is in line with the dosage on the package for the heart guard. Heart guard also contains Pyrantel Pamoate for the intestinal parasite's like round worms. So I use Pyrantel Pamoate once a month also to take care of those critters. I give it to them on a piece of bread also. The Pyrantel Pamoate is the most common intestinal wormer, it has many names, one common name I can think of is Nemex. All this is easy to get and cost allot less than what you buy at the vet. I have been doing this for four years now, I take my dogs to the vet once a year for their rabies shots and have them do a fecal test, and blood test for intestinal, and heart worms. The test have always been negative. I also use a product called BioSpot for a monthly flea and tick treatment. Works just as good or better than the Advantage (etc. ) you get at the vet, and its allot cheaper. ($6 or $7 verses $30). I have no experience with cats, so I can't help you any there.