Prong collars can cause pain, discomfort, and potential injury to dogs due to their design, which uses metal prongs to pinch the skin around the dog's neck when the dog pulls on the leash. They have been associated with physical harm such as puncture wounds, nerve damage, inflammation, cough, and even windpipe collapse in severe cases, according to veterinary experts. Additionally, prong collars can cause distress and confusion for dogs, potentially leading to behavior problems by associating pain with unrelated stimuli like people or children. For these reasons, many experts and organizations consider prong collars to be harmful, painful, and an ineffective method for training dogs, and they do not recommend their use. However, some trainers argue that if used properly, prong collars distribute pressure more evenly around the neck than other collars and can be safer than flat or choke collars, although misuse or inexperienced handling increases the risk of harm. Overall, the consensus leans heavily toward prong collars causing both physical and mental suffering to dogs and advocating positive, pain-free training methods instead.