Red rubber urethral catheters can be difficult to place in female dogs since the catheters are not as rigid as polypropylene catheters. But polypropylene can be traumatic. A polypropylene catheter makes a great stylet for the red rubber catheters, however, if you use a polypropylene catheter one or two sizes smaller than the red rubber catheter.

Ashley Purser, veterinary assistant
Grand Junction, Tenn.