Our girls don't roo. In fact, none of the four greyhounds we've adopted have ever rooed. And Sadie and Katie get nervous whenever a group of greyhounds begin barking and rooing as is sometimes done during, or at the end of, greyhound gatherings.
A pity...I think they'd be good at it.
So I must be content with being with other people's greyhounds to get a rooing picture.
Bootsy is one such greyhound. He roos with the slightest of provocations. I was on my way home from my first-time going to the Greyhounds in Gettysburg event in 2010. I hitched a ride with my friend and her family to BWI, stopping at her sister's home on the way there for a drink or two. The house has enormous amounts of light spilling through the back windows (which I noticed while we were all talking); it was totally wonderful. And the red-painted dining room wall complemented Bootsy's tiger stripes. I don't recall how Bootsy was prompted to roo but he kept going as my friend's sister joined in.
I didn't want to use bounce flash because the light was wonderful already but I still needed to up the ISO so Bootsy would not blur as he rooed. I took a number of pictures -- this one came out best after some cropping.
(Shot with the Nikon D300 using the 18-200mm set to 50mm; program-mode; camera chose 1/80 sec at f/4.8; ISO 800; auto white balance; matrix-metered; normal JPG.)