I raise beagles and am in a constant battle with fleas and ticks, my dogs are constantly exposed to them when they hunt. If you only have a couple of dogs, get some Seresto flea and tick collars. They are expensive, but they work as good or better than anything else on the market. I have too many dogs for them to be economical for me, but I know a lot of guys with 1-3 dogs and they all swear by them. Depending how big your dogs are, you might be able to use one collar for two dogs. Get the biggest size they make and cut it in half. You'll have to determine how big the necks are on your dogs. I've tried everything that is on the market and if I only had a couple of dogs, the Seresto collars is what I would be using.
Shop around for the best price. Sometimes they can be had on ebay for a good deal.
https://www.amazon.com/Bayer-Seresto-Collar-Large-Protection/dp/B00B8CG602
