Kidney disease is a degenerative condition that causes harmful toxins to build up in your kitty's body. Symptoms of kidney disease include lethargy, lack of appetite and bad breath. If left untreated, it will eventually lead to death. The only way to diagnose kidney disease or kidney failure in your kitty is for your vet to perform blood and urine tests. Your vet will interpret the results to determine whether your cat's kidneys are functioning properly.
The Vet Visit
If your cat has been eating less, has been drinking more or has been very lethargic, bring her to the vet for a checkup to determine if kidney disease could be the cause. During a physical exam, your vet will palpate the kidneys to see if they are enlarged, which would indicate that they are inflamed or infected. He may also smell her mouth, because cats with kidney disease have bad breath that smells similar to ammonia or urine. Your vet will weigh your cat to determine whether she's lost any weight since her last visit. The vet may perform blood tests and urine tests, and may take X-rays or an ultrasound of the kidneys to determine whether they look abnormal.
Your vet will run a complete blood count on your cat's blood sample to see if the values of chemicals in it are normal. Healthy kidneys filter out the waste products of your kitty's body; if waste chemicals have built up in her bloodstream, the vet will know that the kidneys are not functioning correctly. The main blood values that indicate kidney problems are her kidney enzyme values -- namely her creatinine and blood urea nitrogen or BUN levels. If either of these values is elevated, her kidneys might not be properly filtering these chemicals out of the body. Your vet will take a urine sample from your kitty to see if it is very dilute, if it contains protein or if it contains sugar, all of which can indicate kidney disease, according to petMD.
Important Blood Values
Several blood values can indicate kidney disease in your cat. The normal range of values for her BUN is between 14 and 36 mg/dL; values higher than 36 mg/dL can indicate kidney issues. Normal creatinine values are between 0.6 and 2.4 mg/dL; higher values can indicate kidney problems, especially if both the BUN and creatinine levels are elevated. Extremely high BUN values of 90 mg/dL or creatinine values around 8 mg/dL can indicate that your feline friend is in kidney failure. The creatinine values are especially important, because highly elevated levels usually mean that the kidneys are functioning at 25 percent of their normal capacity or less, according to veterinarian Shelley Knudson on the All Feline Hospital website.
Once your vet makes a diagnosis of kidney disease for your cat, you need to continually monitor her blood and urine values for the rest of her life -- because there is no cure for this condition. Your vet will tell you how often to come in for retesting based on your kitty's physical condition and her previous blood results. Depending on the cat's blood and urine values, your vet may recommend putting your kitty on a low-protein prescription diet or giving her intravenous or subcutaneous fluids. Fluid therapy helps to make your cat's blood more dilute and less acidic from the toxins that build up in it. It also makes it easier for her kidneys to filter any remaining toxins out of the blood.