Many dog owners are noticing small (less than 1 inch diameter), bullseye patterned marks on the underside of their dog. These marks are often caused by a species of gnat that emerges from the grass and bites the dog. The bites cause a bullseye mark that many confuse with a bullseye rash caused by the Lyme disease bacteria. It is important to note that dogs do not develop a bullseye rash with Lyme disease exposure, only people do. As angry as the gnat bites look, they usually do not bother the dog to any noticeable degree. If you do think your dog is a little itchy, you can try giving it a bath in oatmeal based pet shampoo. More pronounced itching may need to be evaluated by a veterinarian. We know that these bites are alarming to see, but if there are no other problems with your dog, it is reasonable to monitor the situation and the bites should go away in a couple days. The gnats are generally seasonal, being most problematic in the spring, but it is possible to see bites on your dog throughout the summer. Avoiding grassy areas while the gnats are prevalent is the best defense for your dog.