Urine incontinence is not a common problem in chinchillas. It appears “wetters” were first documented in the 1940’s on a ranch in Virginia, USA.
Has your chinchilla ever shown signs of incontinence? Do you know what this can be a sign of?
It is basically a genetic deformity of the urinary system, resulting in incontinence. The entire belly is usually soaked in urine and it is incurable.
To keep the chinchilla comfortable and prevent from urine scalded, what you could do to his fur was clipped away from his bits, as it was only getting soiled and matted. Keep him clean and washed his belly with a mild antiseptic solution and dried with a hair-dryer on a cool setting.
In more serious cases, you could see that the chin walked with it bottom very high in the air as it was sore and miserable. It could also lead to infections (picture below) eg. cystitis or bladder stones and Veterinary treatment and diagnosis is essential.