The neonatal period

The neonatal period is from birth to the day the eyes open, at around 13 days old.

The newborn puppy is a completely dependent being, orienting itself by touch and heat sensitivity but with seemingly limited capacity to control its activities or to learn. Research into the neonate is in its early stages, however it is possible that the future holds surprising discoveries about the importance of this period, especially concerning the effect of manipulation on neuro-hormonal development.

Of particular interest to people raising working dogs is the development of the serotonin reflex. Serotonin is involved in managing emotions and making judgements, it keeps us focused and calm.

When a puppy receives a mildly new stimulus, it startles and the cerebral cortex releases norepinephrine (or noradrenaline) initiating the fight-or-flight response. The hair sleeks, muscle tone increases, and the heart rate rises. When puppy is reassured the serotonin system turns off the alarm, triggering a relaxation response where muscles relax and the heart rate drops.

A puppy raised in isolation without any new stimuli will have a 'strong' norepinephrine system, and a 'weak' serotonin system. It will tend towards a fight response to even minor threats. A puppy that is heavily stressed during this period will have the reverse, and will be inclined to be fearful and overly submissive.

The norepinephrine and serotonin systems are described by Lithgow as the dogs work/rest systems. The systems need to be in balance to have a good working dog. He says to pick the best pup from a litter, measure their heart rates at one week old. The puppy with the highest heart rate has the best 'work' system. Then subject it to mild stress to develop its 'rest' system. His mild stress program is similar to Battaglia's Bio Sensor program.