Turns out Bruno has Cognitive Dysfunction Syndrome, a sort of dog Alzheimer's. Fortunately there is a plan of treatment involving drugs so I'll be trying that. Here's hoping they help him get back to his old self.
What does the Universe have against me sleeping? Finally got to sleep at 2:30 AM. Then the thunderstorms started rolling through the area at around 4:45 AM. At around 5:30 AM I wake to a lot of snarling and yipping. I thought maybe a wild critter had gotten into the house somehow and the dogs were after it. I flew out of bed and found Durango sitting on top of Bruno. Separated the two of them and tried to go back to sleep. Then at around 6:00 Bruno starts whining because of his allergies. Got up and gave him his meds. Finally got him settled down again. Now I'm awake. Going to make an attempt at getting some more sleep.