If you notice red, angry-looking circles on your dog’s stomach, it may not be as serious as it appears. According to the Morinville Veterinary Clinic in Alberta, Canada, these marks are often caused by fly bites, particularly black flies, which are common in North America, especially in northern regions. While they may look alarming, these bites typically don’t bother dogs and heal on their own without treatment. The flies usually appear during spring and disappear after a few weeks. Many pet owners found relief after learning they didn’t need to rush to the vet for costly bills. However, experts caution not to overlook similar marks, as other pests or allergic reactions could be responsible. Always consult a vet if you’re concerned.