There could be various reasons why your Golden Retriever's hair isn't long. To begin with, the genetics play of the puppy's parents have an important influence in defining a dog's coat or puppy coat type, color, and length. While the Golden Retriever breed is noted for its long, flowing coat, individual dogs' coat length may vary due to genetic causes. Your dog may have received genes that cause the dog's coat to become shorter. Another possibility is that it is related to grooming. Brushing adult coats and grooming golden types of Retrievers regularly is necessary to maintain their longer outer coat and fluffy coat and avoid matting. If your Golden Retriever coat isn't groomed frequently or adequately, it can become tangled and matted, so the dog begins to lose fur, resulting in a need for a shorter haircut. Finally, medical issues such as allergies or hormone imbalances can have an impact on the length and quality of a dog's outer coat. If you have any concerns about your dog's outer coat, you should always contact a veterinarian to rule out any underlying health issues.