I was alerted to the fact that some high-end no-grain kibble might lead to crystals in a dog’s urine — not because of any of the ingredients, but due to a chemical interaction of the kibble in my dog’s body.

I brought a urine sample to my vet, and sure enough, there were a few crystals. However, the pH was fine, and my vet was not overly concerned. She mentioned changing to another kibble but without any urgency. Would you comment on this?

June
Waltham, MA

Yesterday was cat urine day on the Vet Blog, so it’s only fair that today we cover dogs.

It has for a long time been conventional wisdom among veterinarians that some diets can lead to crystals in dogs’ urine. This is especially true in breeds that are predisposed to crystals and bladder stones. Therefore, changing your dog’s diet may eliminate the crystals and reduce the likelihood that stones will develop.

However, in dogs (unlike cats), urinary crystals are often caused by bladder infections (in cats, crystals most often occur without infection). Therefore, the first step that should be performed, before a diet change, is a urine culture on a sample collected by bladder tap (see yesterday’s post).

Also, as I mentioned briefly yesterday, urine should be analyzed as soon as possible once it has been collected. Sometimes crystals form in the sample after collection, and this can complicate interpretation of the sample.