Spring is finally here in the Northeast—and while we’re all enjoying the longer days, warmer temps, and time outdoors with our pets, so are the bugs. As the weather changes, we start to see a rise in fly and tick activity, which can lead to some confusion when it comes to what’s normal and what’s not, especially if you notice a red ring or “bullseye” lesion on your dog.
Mayflies, Blackflies, and Bullseyes—Oh My!
This time of year, we see many dogs with red, circular marks on their skin, most often on their bellies, armpits, or around the ears. These are commonly caused by mayfly or blackfly bites, and they’re more of a cosmetic nuisance than a medical issue. In fact, they often look exactly like the bullseye rash humans get when infected with Lyme disease—which can understandably cause concern.
Here’s the key difference:
Bullseye lesions are actually very uncommon in dogs with Lyme disease. When we do see them, they’re much more likely to be the result of fly bites than an infection.
What Should You Do?
In most cases, these bites don’t require treatment and will go away on their own. However, if the area becomes irritated, swollen, or starts to bother your pet, feel free to reach out. We’re always happy to take a look or review a photo to make sure it’s nothing more serious.
If your dog tends to react more strongly to fly bites—developing bumps, scabs, or discomfort—there are topical preventatives like Vectra 3D that not only protect against ticks but also help repel flies and mosquitoes. Oral preventatives, while excellent for tick and flea control, don’t offer protection against biting flies.
Don’t Forget the Ticks
Alongside the flies, tick activity is also on the rise, and we strongly recommend starting (or continuing) tick preventatives. Because our winters have become milder, year-round prevention is often the safest option.
When in Doubt, Reach Out
Attached to this post is a photo of a typical mayfly bite on a dog for your reference. If you see something similar and you’re not sure what it is, don’t hesitate to call us or send us a picture. In most cases, it’s nothing to worry about—but we’re always here to help.
Enjoy the season—and keep those tails wagging safely!
Dr. Mordasky