We use Frontline on our dogs and it seems to do a pretty good job. The mosquitoes don't seem to be out much during the day or at least in the sun so we haven't had too much problem with that. So far none of our dogs have picked up ticks at the dog park (and we go 5-6 times a week). Nor have I found fleas on them - I don't know what chiggers are so I can't respond to that. Lately because of the humdity we have been going later in the evening and when the mosquitoes start biting us, we leave but again there hasn't been too many. Although it has been raining a LOT this weekend. And is suppose to continue through this week. Frontline is sold at Pet Supplies Plus and there is one in Findlay.