re: Dog flea and heartworm meds

Vet here.
Heartgard is crap now-a-days. There has been much resistance to ivermectin (which is the ingredient in Heartgard), especially in the South where mosquitoes are prevalent and the ingredient Ivermectin has been around forever.
There are much safer products these days .

Trifexis is the best for heartworms, intestinal worms, and flea control combined. Plus it is much cheaper than doing the Proheart 6 injection combined with a separate flea/tick preventative.

If you are not concerned about fleas, the Proheart 6 injection is the way to go. Covers heartworms and intestinal worms.