**an excerpt from A Novice Looks at Puppy Aptitude Testing, By Melissa Bartlett, originally published in Pure Bred Dogs, American Kennel Gazette, March 1979 1-3 weeks (1-20 days). The puppy needs warmth, food, sleep, and his mother. Neurologically very primitive, the puppy responds by reflex and essentially it is unable to learn. 4th week (21-28 days).Continue reading “Puppy’s Critical Stages of Learning”