This is insane! First thank you for your site. 
My parents cat was put on metacam after an injury - she took it for a week!  Then she started vomiting and and was lethargic not eating - they took her to the vet and the vet said the medicine just upset her stomach and did NO tests.   A few days later the cat was MUCH sicker and THEN the vet did blood work and said her kidneys were failing - STILL no mention of the medication causing it - The next day after IV fluids the vet did a urine test and told us that the cat must have gotten into antifreeze b/c she found ethylene glycol crystals in her urine - The cat had been indoors for 3 weeks closely supervised so we knew this was not right - there is no chance she got into any chemicals or anything.  Her explanation made no sense but our focus was just on getting her better.   Finally today (stupidly we did not research until now) and found your sight and many others.  The vet kept the cat on IV fluids hospitalized for 3 days - she sent the cat home today saying her blood work looks good and gave her some special food and said we'd have to wait and see if there is permanent kidney damage.  The cat seems fine now but I am afraid she may have needed more time on IV fluids and of course we will not go back to this vet who still has no clue what has happened.  We just discovered this on our own very easily - How could a vet miss this!  The cat is less than a year old and weighed only 7 pounds before getting sick!  I don't know where to start - We are contacting another vet for advice on further care.  I have more research to do but don't know where to start.  My parents paid this vet over $500.00 to almost kill their cat.  I want to recover their money but more important I want to hold this vet accountable and make sure this is not happening to other cats.  She is totally negligent I think.  Do you have any experience that would relate to these issues.  I see lots of good info on your site that I am going to go look into more now.  From your experience do you think our cat has a chance of living a normal life now?  She had 3 days of IV fluids and is now eating and drinking but I am so afraid she will relapse now based on what I have read.  Thanks!