Red eyes of dogs may be caused by odor, bacterial infection, canine distemper, conjunctivitis, keratitis, or foreign body irritation. You need to check whether there are foreign bodies in the dog's eyes. If there are foreign bodies, you should promptly Clean up, and at the same time improve the dog's diet and instill antiseptic eye drops; but if the dog appears to be in poor spirits, vomiting and diarrhea, etc., it is best to take the dog to the pet hospital for examination immediately to avoid delaying the condition.