Cystinuria in the Newfoundland dog is indicated by the presence of cystine stones in the kidney, bladder or ureter. Failure by the kidneys to reabsorb amino acids results in the formation of these stones. In this disorder, the kidneys do not adequately reabsorb certain amino acids during the filtering process, thus resulting in excess excretion of these amino acids. The amino acids may precipitate and form crystals or stones in the kidneys, ureters, or bladder.

• Newfoundland

A (CLEAR/NORMAL): These dogs have two copies of the normal gene and will neither develop cystine stone disorder nor pass this mutation to their offspring.

B (CARRIER/NOT AFFECTED): These dogs have one copy of the normal gene and one copy of the mutation associated with this disease. They will not develop cystine stone disorder but will, if bred, pass the mutation to 50% of its offspring, on average.

C (AT RISK/AFFECTED): These dogs have two copies of the mutation associated with this disease and are susceptible to develop bladder/kidney stones.