Cystinuria in Dogs

Category: Urinary & Reproductive
Inheritance: Autosomal recessive
Breeds documented: 4
Published sources: 5

Overview

When the kidneys fail to reclaim a substance called cystine, it builds up in urine. It can then form stones in the bladder or kidneys. This inherited problem is called cystinuria, and some affected dogs show no outward signs until stones develop. A stone can block urine flow, a serious complication that requires emergency veterinary care.

Signs to watch for

Straining when trying to urinate
Passing small amounts of urine more often
Unexpected toileting accidents indoors
Blood appearing in the urine
Straining without producing urine when stones cause a blockage

Stones can first cause signs in puppyhood or later adulthood, depending on the form.

Emergency Go to an emergency vet now if your dog strains without passing urine.

Diagnosis and tests

A vet tests urine for cystine crystals and other urinary problems. A separate urine screening test can detect excess cystine. Specialized X-rays or ultrasound can help find stones in the bladder or kidneys. DNA tests are available for some breeds, but the appropriate test depends on the form involved.

Breeds with documented risk

4 breeds

By breed size

1 Toy
2 Medium
1 Giant

NewfoundlandGiant · Working Group
Australian Cattle DogMedium · Herding Group
Miniature PinscherToy · Toy Group
Irish TerrierMedium · Terrier Group

Inheritance

This condition has more than one known form, and different breeds inherit it in different ways. The sources list the form found in each breed.

Autosomal recessive
Newfoundland, Labrador Retriever
A dog is affected only if it inherits two copies of the gene variant, one from each parent. A dog with one copy is a carrier: usually healthy, but able to pass the variant on. When two carriers are bred, on average one puppy in four is affected. A DNA test can tell clear, carrier and at-risk dogs apart.
As stated by OMIA
Autosomal dominant
Australian Cattle Dog
One copy of the variant, from either parent, is enough to put a dog at risk. On average, an affected dog passes the variant to half of its puppies. Males and females are affected equally.
As stated by OMIA
Autosomal dominant
Miniature Pinscher
As stated by OMIA

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.