modification to reduce salt and protein intake (especially methionine). If this fails then patients are usually started on chelation therapy with an agent such as penicillamine. Tiopronin is another agent. Once renal stones have formed, however, the first-line treatment is endoscopic laser lithotripsy. ESWL (Extracorporeal shock wave lithotripsy) is often not effective because of the hardness of the stones that do not fragment easily. Conventional open-abdominal surgery is rarely used but has proven to be effective treatment modalities for patients with more advanced disease. Adequate hydration is the foremost aim of treatment to prevent cystine stones. The goal is to increase the urine volume because the concentration of cystine in the urine is reduced which prevents cystine from precipitating from the urine and forming stones. People with cystine stones should consume 5 to 7 liters a day. The rationale behind alkalizing the urine is that cystine tends to stay in solution and causes no harm. In order to alkalize the urine, sodium bicarbonate has been used. One must be careful in alkalizing their urine because it could lead to other forms of stones in process of preventing cystine stones. Penicillamine is a drug that acts to form a complex with cystine that is 50 times more soluble than cystine itself. Percutaneous nephrolithotripsy (PNL) is performed via a port created by puncturing the kidney through the skin and enlarging the access port to 1 cm in diameter. Most of the time, cystine stones are too dense to be broken up by shock (ESWL) so PNL is needed. Videos of surgery are available on various websites that show stone removal by percutaneous nephrolithotomy. In February 2017, an article was published in Nature Medicine entitled "Alpha lipoic acid treatment prevents cystine urolithiasis in a mouse model of cystinuria", suggesting that a high dose of the readily available antioxidant, alpha-lipoic acid at 2,700 mg/67 kg body weight daily reduced the incidence of stones. The effects were dose dependent. The results are unprecedented for cystinuria. A clinical trial is underway based on this mouse model. Occurrence in animals This disease is known to occur in at least four mammalian species: humans, domestic canines, domestic ferrets and a wild canid, the maned wolf of South America. Cystine uroliths have been demonstrated, usually in male dogs, from approximately 70 breeds including the Australian cattle dog, Australian shepherd, Basenji, Basset, Bullmastiff, Chihuahua, Scottish deerhound, Scottish terrier, Staffordshire terrier,