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.
A strong work ethic dog, the Bergamasco is a big fluffy breed with distinguishing characteristics of its coat. The hairs seem to be âdog hairs, âgoat hairs, while wool can also be noticed. These hairs combine to form black or gray mats which grow throughout Read More. Image.
The different mastiff breeds have been bred for guarding and for fighting. The two most expensive dog breeds in the world are the Tibetan Mastiff and French Mastiff. A Tibetan Mastiff. The largest Tibetan Mastiffs can stand over 31 inches tall and the breed typically weighs over 140 lbs. The dogs can be black, grey, brown or even, in some rare instances, completely white.