Try calling your vet and tell them the valium isn't working. They may be able to adjust the dosage if covering the crate doesn't work. I was given valium for my cat, the first time I tried it he couldn't even walk he was so drugged. I contacted the vet and she said drop the dosage to 1/4 of a pill instead of half. That works great, it keeps him calm but still fairly functional. You may need to go the other way if possible.