Holistic Vet, 
I'm interested in learning about natural heartworm prevention. I have a seven year old English Cocker Spaniel who has been dewormed with Drontal Plus/Cantel every three months as a precaution. He was dewormed with Cantel in February 2013, and for some reason, the vet also dewormed him with Strongid in March (which was about a month apart rather than the usual 3 months). My concern now is that he is aging, and I am worried about overvaccinating and overdrugging him but still want to maintain adequate protection for him. What would you recommend for natural heartworm prevention? We live in Cincinnati, OH these days and were wondering if you could answer our questions: 1. My dog goes out for walks at the dog park. How often does he need to be dewormed, or should we only stick to deworming based on yearly fecal results and/or signs of parasites in poop?
2. Should we put him on a heartworm preventative? He has been on ivermectin treatments before while being treated for mange and ticks, so I remember the days he used to be very lethargic. What is a a safe heartworm preventative you would suggest, and how often should we use it in Cincinnati? (He was not on heartworm prevention before since the vet said mosquitoes were not a problem in that region before we moved to Cincinnati.)
Answer: As to deworming, it's exceedingly rare for adult dogs to get worms, except perhaps for tapeworms, which are the most benign worm on the planet. The drug is likely worse than the worm. You can use fecal tests to verify the presence or absence of worms and decide from there. I would never recommend routine deworming.
