However, a paragraph in the story told me something that I had known nothing about, and it caused an important lesson to click for me.
Sage had been found, and Carrie was called by Animal Control to come and get her. This occurred several hours after Carrie had the good fortune to have seen Sage with her own eyes (thanks to a sighting called in to her), and then watch her dog retreat and disappear because she didn’t recognize her owner (of thirteen years). Carrie had called gently to Sage, but Sage didn’t recognize her by sight or sound.
In the article, Carrie explained what she understood about why Sage couldn’t recognize her.
So I tried looking it up. Most of the information on the topic that I’ve found is pretty dry, and not an easy read for a person like myself without a science background to take in fully. And honestly, I have yet to find more than a very few sites that seem to be interested in detailing the relationship between serotonin and short term memory (although the relationship between serotonin and depression are much easier to find.) But I did find a 2002 article published in Science Daily, entitled Depletion Of Body Chemical Can Cause Memory, Mood Changes, that explained it in terms easier for the lay person to grasp.
If I'm paraphrasing correctly, scientists at the Brain and Behavior Institute at the University of Maastricht in the Netherlands lowered the levels of the amino acid tryptophan, and as a result, those of the chemical messinger known as serotonin, in 27 volunteers. Among other effects, the article's author Wim J Riedel and colleagues found impaired ability to recall and recognize words they learned during the period when the tryptophan (and serotonin) levels were lowered, yet not before this period. As stated in the article, "while the study is not definitive and does not offer a solid conclusion that eating more tryptophan will enhance memory or mood, it does indicate a possible connection."
Up to now, I've always had to be vague about the reasons when I coach lost dog owners to avoid calling out to their dogs when seeing them, as long as they are still uncontained, of course. I do always, always explain that they need to be prepared for their dog to not recognize them, and to not take it personally. Of course, some will say "oh my dog will recognize me" and I then do my best to convince them that the dog MIGHT not recognize them, and that there is a lot of precedent for making this statement.
I do want to continue reading on the subject to understand it more fully, and to find more evidence of this concept, and a link between what is found in people and what's found in dogs. But, it's great to now be able to give an explanation with a little science behind it. If a dog's diet, or food intake, while at large for a prolonged period is lacking in tryptophan, you may be able to predict that the dog will be less likely to immediately recognize the owner during their initial encounter.
