Summer time is flea and tick season. Both fleas and ticks are quite small and are hard to identify right away. That is why you want to be treating your dog when you know they are in season. I have NEVER been a fan of using oral flea and tick medication. Why treat an external issue internally? Instead, I recommend using one of these two products:
Frontline is a topical product that you apply once a month. It comes in different sizes based on weight. A little secret about Frontline is that it comes in different volumes but it is all the same price. By buying the largest size you may be able to get several doses out of it.

Seresto Collars also treat for fleas and ticks. One collar is potentially good for 8 months. The key with this product is to make sure it is tight enough around your dog’s neck, if it isn’t it will not be effective. Treat it like any other collar you would put on your pet, it should be close to the skin but not too tight that it could choke them.

