Cystinuria in Dogs: Stone Welfare Management

Key Facts

• Cystinuria results from defective renal tubular reabsorption of cystine causing crystallization in alkaline urine
• Cystine stones form in the bladder and urethra, causing obstruction — a life-threatening emergency in males
• Most commonly affects Newfoundland dogs and English Bulldogs, with males more clinically affected
• Medical management includes alkalinizing diet, increased water intake, and 2-MPG or D-penicillamine
• Surgical removal of stones provides immediate relief but recurrence is common without ongoing prevention

Welfare Considerations

Cystinuria causes welfare suffering through urinary obstruction and chronic urinary tract irritation. Male dogs at high risk of complete urethral obstruction face a welfare emergency causing severe pain and death without treatment. Welfare-centered management combines dietary and medical stone prevention with owner education to recognize early obstruction signs. Genetic testing is available for some breeds to eliminate affected animals from breeding programs.

What You Can Do

• Monitor urine pH monthly and maintain alkaline urine (pH 7.0-7.5) through diet to prevent crystallization
• Increase water intake as much as possible — dilute urine reduces cystine crystallization
• Recognize signs of urethral obstruction: straining with no urine, crying in pain, distended abdomen
• Discuss 2-MPG or D-penicillamine therapy for dogs with recurrent stone formation
• Test breeding Newfoundlands and Bulldogs for cystinuria mutations to reduce disease frequency