That's very true, growler!
She has never been one to overexert.
She has valvular heart disease of some sort, Patti--rapid development of a grade 3 heart murmur--but as far as we know, it's idiopathic. All her blood work and xrays looked good, and the ultrasound showed relatively normal function despite the murmur. She started with a soft cough a while back, at which time we added the meds. Thanks for that link--I'll check it out!
Thanks, Barkingdog. She's not much for overexertion and stress isn't in her vocabulary!
We do spend a lot of time with all our dogs, knowing that they're getting older and not wanting to waste a minute with them if we can help it!