Some dogs will respond to ultrasonic, and some won't. We haven't used one ourselves, but that's what I've read. My dachshund doesn't seem sensitive to noise, so I don't think he'd care. Our rescue would probably be cowering and shaking in a corver if we had an ultrasonic.
Our dachshund barks if we both leave the house. We tried a bunch of stuff, but the only thing that works is this bark collar, 89$.
https://www.amazon.com/PetSafe-Anti-Bark-Training-Correction-Waterproof/dp/B004HKMEX0/
It zaps them but it's not bad (yes, I tested it on myself). And it starts out at a low level of shock and increases the level until they stop.
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Steve
'08 Boxster RS60 Spyder #0099/1960
- never named a car before, but this is Charlotte.
'88 targa
SOLD 2004 - gone but not forgotten