Canine Cystinuria is a rare genetic defect characterized by the formation of crystals or stones in the urinary tract. These formations are due to failure of the kidneys to process an amino acid called cystine. If stones form, they can block the urethra making urination painful and/or impossible. If it is not treated quickly and carefully by your vet, your dog will die.

Fortunately, Canine Cystinuria is a rare condition and it’s even rarer for it to result in full blockage of the urinary tract. Noid is special, though. He is the only documented case of a Chinese Crested with Canine Cystinuria.

What are the Symptoms?

Bladder stones may cause blood in the urine (hematuria) (giving the appearance that the animal is urinating blood) but sometimes there may be no signs at all. Painful urination or straining to urinate are other signs. Urinary tract infections are commonly associated with bladder stones. Smaller stones may become lodged in the urethra, especially in male animals, causing urinary tract obstruction and the inability to urinate. This condition causes acute renal failure, hyperkalemia, septicemia, and death within a few days.

What is the treatment?

Cystine (SCH₂CHNH₂COOH)₂) stones form in an acidic to neutral urine. Because this is a rare disease, there are few treatment options. Most vets recommend a diet low in protein in order to encourage alkalization of the urine. This will not help dissolve crystals which have already formed, and if the urine becomes acid for even a short time, crystals can form.

There are drugs which can help, as well. Cupramine (d-penicillimine) is fairly easy to obtain but is associated with several side effects, including liver failure. The other drug is called Thiola, which has good success and few side effects. Unfortunately, it’s hard to obtain and very expensive.

The most important issue is to unblock the urinary tract. Various surgeries are recommended at different stages. For immediate relief, a procedure called hydropulsion is used. The stones or crystals are pushed back into the bladder, A follow-up cystotomy will be necessary to remove the stones. If blockages are recurring, a scrotal urethrotomy may be necessary. This surgery creates a new opening for urination between the scrotum and the penis. A cystomy is performed at the same time. This surgery is complex and recovery is challenging, but the success rate is 90-95%. Here’s a link to detailed descriptions of these surgeries.

Stay tuned during Noid Week to see how Noid has battled Canine Cystinuria!