The Chihuahua is a tiny toy sized dog. The Chihuahua is a good companion dog. Courageous, extremely lively, proud and adventurous, they enjoy affection. Brave, cheerful and agile, Chihuahuas can be strong-willed without proper human leadership. Socialize them well. They are intelligent, learn quickly, and respond well to firm but gentle training. They are good little dogs for apartment life. The Chihuahua likes warm weather and dislikes the cold. This breed is an average shedder.