I think you just answered your own question. Could be the frustration of your Weimerainer that the cat is picking up on and expressing it also.

Once I had a persian who was behaving like that and the vet prescribed depression meds - it helped

Could there be a problem with the pads on her feet?
Maybe the litter hurts them..

maybe put the pads in the bcx she may not like litter.we had one like that till we figured it out she didn't want her paws to touch dirt or litter. at least that took care of her problem.

Medication is available - one of my daughter's cat was put on Prozac (yes, Prozac) and is doing much better. She has 6 kitties.

Have you tried using the litter that is shaped like pellets, i think it is some sort of wheat pellets. Maybe a different type of litter might help.

that is why i dont have a cat LOL

We had 2 babies dumped in the parking lot right near us the week after Christmas and I took them knowing I could take them to the kitty shelter the next day only to find out, they weren't taking any new kitties. Oops!!! So we inherited 2 (boy & girl) to go with out quite large fixed female. They were starving and I figured only about 4 weeks old but did not have any problem eating and when I set up the litter they went right to it. I almost fell out. The little black one (tiniest) had diarrhea so bad it was sad. Could not make it to box. Got some Probiotics & it took about a week and she got better. Was only 1# when she was 7 weeks old after being so sick, but is eating like a horse. I am going broke. Little Max is twice as big but they are so much fun to watch them frolicking. Hopefully you can hang in there with her. I googled cats with peeing problems and found lots of sites that told a lot so maybe try some. Good luck.

Peg-TX

We've had 4 cats - not at the same time - but everyone of them had issues with my husbands shoes. Not a nice thing. We got them "fixed" and that behavior stopped. Have you tried that? We had to wait for the females to come of age. We're now having trouble with one little darlin digging in the carpet when they have about 4 stratching post of various types and sizes all over the house. I did have a persian and loved him dearly. He aged and developed some health issues and eventually died in his litter box. Had to get a box with a lid because my first little darlin thought he had to dig to China before he could go. Had litter all over the room. My persian wanted privacy so it worked out.
Who knows what evil lurks in the minds of cats and we still love em. Why??

We've had 4 cats - not at the same time - but everyone of them had issues with my husbands shoes. Not a nice thing. We got them "fixed" and that behavior stopped. Have you tried that? We had to wait for the females to come of age. We're now having trouble with one little darlin digging in the carpet when they have about 4 stratching post of various types and sizes all over the house. I did have a persian and loved him dearly. He aged and developed sone health issues and eventually died in his litter box. Had to get a box with a lid because my first little darlin thought he had to dig to China before he could go. Had litter all over the room. My persian wanted privacy so it worked out.
Who knows what evil lurks in the minds of cats and we still love em. Why?? We all like the litter you can get at Costo. That's the only place I've seen it. I tried those pellets. Cats did not like that at all. My friend had hers declawed and her vet recommended the pettets but the cat had other ideas. She didn't like then either. I gave my bag away. Evidently it's really good at soaking up spilled oil.