So I got the floor grate in the mail today and just assembled it to the crate. I think it will work well if Tayda has an accident. I think the grids might not be too comfortable if they had to stand/lie on them directly, but I put their two big dog beds in and they pretty much take up the whole area of the crate floor. I put the towels under the grate so that if she has an accident it will hopefully fall through onto the towels. It's actually quite a good idea - I had no idea they made these add-on floor grate things until just last week! Tayda has been really good about peeing under the beds onto the towels so hopefully she will still do that now that they are in a separate little compartment. There's about 2 inches of space between the new floor and the old floor so it didn't take away too much of their headroom. I was worried about that.
Thankfully - Tayda has been holding it while I've been at work for the last couple days, so maybe it was due to the UTI that she couldn't hold it before. Fingers crossed. But the "just in case" grate thing will be in place just in case she has an accident! Here's some pics of their new digs!
Thanks to everyone who chimed in on this thread while I was having a nervous breakdown about Tayda. It really helps to have all of your support/ideas/comfort!