Scientific exploration continues.

Gustavo and I practiced on Monday morning. The exact same time, the exact same place as Sunday. The difference was that on Sunday, he could barely run, eat any kind of treat, focus, or play. He was weirdly quiet and calm. He could kind of, sort of, do agility, but just a little. He once ran under the a-frame to hide.
Otterpop filled in for him. Otterpop ran pretty much her normal Otterpop way, as she can do. Not her best, but not her worst. Produce the frisbee and off she goes.
But on Monday morning, Gustavo was cuckoo for any kind of treat I offered him.  Boring, vegetarian treats. He was tugging madly for a little piece of cheese hidden in the corner of a tuggy, for up to 5 minutes straight Because yes. I timed this. He was running VERY FAST. And VERY FOCUSED. He could do no wrong. He just wanted to GO! With me. And he could fetch his frisbee. He was barking like a madman, like a BAD DOG barking madman. We made up some VERY HARD courses, courses that were stumping me and Otterpop, and he could run whatever I threw at him, if we made a mistake, he was all, screw it all and lemme at it again!
So what was different?
Sunday:
Lots of other dogs. Border collies. Papillons. Most of whom he knew.
Lots of other people. And their cars, and crates and stuff. Most of whom he knew.
Later in the afternoon he could run after he watched Otterpop run.
That’s about it.
He did improve as the day wore on and I ran Otterpop first. It got hotter. He’s generally sensitive to heat in wilting violet wave a hanky fashion. But a lot of people did leave and later in the day, it became a pretty small group of people and dogs.
He goes to class with lots of other people and dogs, some of who were at the seminar, while Otterpop sits in the car. He is usually very comfortable there, barking and obnoxious and running fast. And focused when he’s focused. Which is not so much lately. He has been to many trials, group practices, fun matches, agility things, in many places over the years, albeit with various degrees of success. 
His old stress mechanism was to stress up and RUN DO MORE TUNNELS! New, sad Gustavo, creepy.
Plucky, rugged, pig brained optimism tells me, this is a training issue that some way, some how, some day, can be overcome. Common sense and the wisdom of looking backwards in time tells me I am chasing my tail in a circle on this one. The background noise of “health issues” is a blinking red flag.
Science project.