Help with Ouija’s life saving treatment

Hello all, as some of you know my sister Brooke has a fur baby Ouija. Ouija hasn’t been acting right recently so we rushed him to the emergency vet where they found he had a urinary blockage. They were able to unblock it, but because it went on undetected for too long, his kidney and potassium levels are dangerously high.The vet said it’s reversible with medication so he has to be kept at the hospital for a few days. The vet gave her an estimate of $5000+. She applied for care credit but it barely made a dent. We want Ouija to get the best care he’s only 3 and has so much life left to live. Please if you can donate anything to help her and Ouija out.