This is not strictly true. Chronic ketamine ABuse can cause urinary tract problems. The doses and frequency used in a clinical session emphatically do not cause this problem. Ketamine has been in regular use since 1970 for a wide range of medical purposes. It's also been on the WHO Essential Medicines List since 1985.
tl;dr - don't need to worry about urinary tract issues unless you're using the drug (1) recreationally; (2) irresponsibly
tl;dr - don't need to worry about urinary tract issues unless you're using the drug (1) recreationally; (2) irresponsibly