Q: My two 6-month-old female Birman kittens are wonderful. Yesterday, they were supposed to have been spayed, but my vet did not do the procedure because their creatinine levels were above the norm. Both cats had elevated levels: One at 1.8 and one at 1.9. Their urine was analyzed and looked good, as did all other vitals. We are very concerned, having lost a marvelous cat to renal failure. Do our baby Birmans have renal problems?
A: A cat’s elevated creatinine levels by themselves do NOT indicate a kidney problem. Creatinine comes from muscle, and cats that are lean and well-muscled will often have creatinine levels that are toward the high end. Cats who eat mostly dry food and do not drink very much water will also tend to have creatinine levels that are on the high end of the reference range.
A vet must conduct a urinalysis on your cat to confirm that the kidneys work properly. The parameter we follow is the urine “specific gravity” (concentration). This varies from around 1.010 (very dilute) to 1.060 (very concentrated).
Cats normally very proficiently concentrate their urine; I’ve seen some cats with urine as high as 1.080. If your kittens have urine higher than 1.035 or 1.040, then their kidneys work fine and there is nothing to worry about. If the urine is less than 1.040 and the creatinine is elevated, then there may be a kidney problem.
The fact that their urine was analyzed and looked good tells me that their kidneys are fine, and that they can be spayed. (Frankly, even if their urine was dilute and they did have kidney disease, a creatinine level less than 2.0 is still very low, and this very mild degree of kidney impairment would not necessarily warrant a cancellation of the spay, unless your vet was delaying surgery because he wanted to have ultrasound performed on the kidneys to look for a congenital or breed-specific kidney disorder.)
Your cats are fine. I think your vet is misinterpreting the significance of the creatinine in light of the normal urinalysis results.