Trained dog peeing in crate

Question
My 7 year old cocker spaniel has a peeing problem.  She had a full blood exam and they found nothing wrong with her.  She was a rescue 3 years ago.  She used to sleep in my room in her own bed, but was peeing there so I started crating her.  She was great for a while but recently she started peeing in her crate at night.  I keep washing her liner with special solution from the pet store, but every night she pees again.  I dont know what to do anymore.  Im feeding her Merrick chicken pot pie dry food and she gets walked at 11pm right before bed.  She never pees during the day while home.  What should I do?

Answer
Are you the same one that posted this elsewhere,

''I recently changed my dogs food from Precise Senicare to Merrick Grammys pot pie, I switched because I read the ratings at Dog Food Reviews - Main Index - Powered by ReviewPost
and wanted her to be on a top rated food. She loves the new food, except since she has been on it she pees in her crate every night. I always walk her right before bed and she has always been good at night in the past. She is 7 years old. I have gone through so many different foods already cause of her inability to digest food. I always fed her kibble and tried wet, but that gave her diarrhea. What can I do? What food would you recommend that is a top rated food that she can digest and wont make her pee and fart all night? I tried evo but that was too rich, I tried California Naturals but she wouldnt eat that. She tried the nutro, but I switched cause of bad ratings. I thought the Merrick would have been perfect but it makes her really gassy and she pees in her bed at night with it. Please help.''

After some discussion another member suggested

''I am glad that your dog is okay. You very well might be right that Merricks has a higher sodium content than others. I don't know. I can tell you when I tried it a number of years ago, my dog did have diarrhea. You mentioned you tried the SD. Did you try to SD W/D with the higher fiber? If not, you can get it at any vet in your area. So, if you are fed up with your current vet, you don't have to go back there if you don't want to.''

I have no better suggestion than the Science W/D.