To determine your dog's breed, you can use a dog breed identification app such as Dog Scanner, Dog ID, or The Dog Key. These apps use advanced computer vision techniques to identify a dog's breed by analyzing its photo. You can simply take a picture of your dog and upload it to the app to find out its breed. Additionally, you can also consider consulting with dog experts, such as breeders, trainers, groomers, and veterinarians, or using a canine genetic heritage test to determine your dog's breed accurately.