The best way to prevent excessive shedding is to brush the dog regularly and provide a high-quality diet. Stress, some medical conditions and food allergies can cause shedding, so treating these is another solution.
Different breeds of dogs shed different amounts, so what seems like excessive shedding may be normal for that dog. Some seemingly excessive shedding is also caused by dead hairs being retained in the dog's coat and coming loose during petting or when the dog rubs on fabric. Regular brushing removes those dead hairs.
Nutritional imbalances and food allergies are common causes of excessive shedding, so feeding a balanced, high-quality food can help. Excessive licking, sores and itchiness are other signs of food allergies that may be present. Changing the dog's diet to avoid allergens often reduces shedding.
Dogs also often shed excessively when stressed or frightened. Dogs who recently moved homes or had other disruptions in their lives may be more prone to shedding that stops naturally as they adjust to their new surroundings. Dogs with chronic anxiety may benefit from the help of a trainer or veterinary behaviorist.
Parasite infections, immune disease and kidney or liver disease are some other causes of excessive shedding that need to be treated by a veterinarian. Certain medications also cause excessive shedding as a side effect, which may not be preventable.