For more information: https://hpets.org/index.php
There's a video expressing the bladder. Here is a screenshot from the excellent video. He put the cat on the side of the kitchen sink and they have a big plastic hair clip on a string attached by the sink. He clipped the kitty's tail with the hair clip to hold it out of the way.
Shows how they put the kitty in a cart. Is that an Eddie's cart? Anyway, they say the cat doesn't like the "wagon" because he can't lie down in it. It appears that his hind end is WAY too high. The back isn't level.
Did you see a way to contact these people (in the Netherlands) and invite them to our bb?
You know, somehow from the Pookie video, you can really get the feel for what is happening. For me it really connects somehow.