As you may recall, our last visit to the Drool Zone promised more watery discussion. So, without any more delay, let's explore why dogs drool.
Remember Pavlov's dog? Ivan Petrovitch Pavlov was attempting to prove conditioned reflex by showing a dog some meat while ringing a bell. The dog drooled because his mouth anticipated eating the meat. Automatically the dog's mouth produced the juice to aid in digestion.
Eventually, the dog would salivate upon hearing only the bell. Pavlov figured people had the same tendencies, not so much drooling, but the conditioned reflex stuff. Had Pavlov done his experiments with humans rather than dogs, the volume of spit would have been more difficult to measure and Pavlov may not have won the Nobel Prize in Physiology and Medicine in 1904.
As we know, dogs have more reservoirs of saliva available to them than people do. This is why we notice the drool factor in dogs that leads to the distressing appearance of glumps of spit on walls and assorted other surfaces in the home.
What is most fascinating to observe drool wise, is when the drool becomes thickened and hangs from the dog's jowls. This strand of saliva has the remarkable ability to stretch, sometimes to great lengths. Then this string swings precariously. You may chase it with a dishcloth hoping to catch it before it lands somewhere but it is difficult to predict its sticky trajectory. This phenomenon is known as the Pendulum of Yuck.