[NAGDU] Off leash dogs! What can I do?

[Julie Johnson]

I've heard of these hand held units that emit a very loud sound, but that 
can only be heard by dogs.   You point the unit in the general direction of 
the approaching dog, press the button and the sound is supposed to startle 
or deter the other dog.  They claim to be made so the sound is mostly 
directed in one direction and it won't bother a dog it isn't directly 
pointed at.  It also says that not all dogs are affected.  I'm skeptical, 
but if it works...hmmm

Has anyone used one of these? What do you think?
Julie
On The Go with Guide-and-Service-Dogs.com
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