Disease overview

A hereditary genetic mutation in the APRT gene is strongly associated with 2,8-Dihydroxyadenine (2,8-DHA) urolithiasis in the Native American Indian Dog. Urolithiasis is a term for the formation of stones (calculi or uroliths) in any part of the urinary tract. These stones form when the urine becomes oversaturated with certain minerals, such as urate, which is a non-water-soluble salt of uric acid. Normally, urate would be converted into allantoin, which is water-soluble and easily excreted in urine. In dogs affected by 2,8-DHA urolithiasis, this conversion process is compromised which leads to increased levels of urate in the urine and an increased risk of stone formation throughout the urinary tract.

Gene name

APRT

Inheritance

Autosomal recessive

Signs and symptoms

Without stone formation, affected dogs will show no signs. As the stone develops, dogs will urinate more frequently, in abnormal places, with the possible presence of blood. If an obstruction forms, urination will cease with frequent straining. This is an emergency situation. Obstruction is more common in males. Stone formation may increase the chances of developing secondary infections.

How is it diagnosed

A veterinarian will conduct a thorough exam, including a review of health history and any clinical signs. Laboratory tests may be required, and an ultrasound is needed to visualize any existing stones. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.

Breeds at higher risk

Native American Indian Dogs

Citations

Furrow E, Pfeifer RJ, Osborne CA, Lulich JP. An APRT mutation is strongly associated with and likely causative for 2,8-dihydroxyadenine urolithiasis in dogs. Mol Genet Metab. 2014 Mar;111(3):399-403. doi: 10.1016/j.ymgme.2013.12.002. Epub 2013 Dec 11. PMID: 24359665; PMCID: PMC4314209.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.