1 Certain parts of the brain shrink, especially the prefrontal cortex (an area at the front of the frontal lobe) and the hippocampus. 2  Both areas are important to learning, memory, planning, and other complex mental activities.
Some big, fluffy dog breeds are the chow chow, the samoyed, the standard poodle, the old English sheepdog and the keeshond. The abundant, fluffy coats of these dogs require constant care. Keep Learning.
The 10 Most Popular Small Dogs Today. 1  1. Pomeranian: The Pomeranian is a very small dog (3 to 7 pounds) that is known for its foxy appearance and curled tail. 2  4. Parson Russell Terrier: As opposed to the first two lapdog breeds mentioned, the Parson is an energetic go-getter.