The Labrador Retriever, Labrador or just Lab, is a medium-large breed of retriever-gun dog. The Labrador is the most popular breed of dog in many nations. Laziness can contribute to this. Obesity is a serious condition and can be considered the number one nutritional problem with dogs. A study shows that at least 25% of dogs in the United States are overweight. Therefore, Labradors must be properly exercised and stimulated.