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.
Largest Dog Breeds: French Mastiff The Dogue de Bordeaux is said to have the largest head in the canine world in proportion to the rest of the body. The average Dogue de Bordeaux measures 23 to 30 inches, and weighs 120 to 145 pounds.