Typically, the softness or hardness of a catheter correlates with the variety of the affected pet and the presence of stone crystals. Different brands and models of catheters describe their hardness differently, but can be roughly categorized into the following types:

Bio-ultra-soft. Made of a special material that is soft and becomes softer as the temperature rises, they need to be operated in conjunction with a guidewire. It is the most biocompatible and can be left in place for up to 15 days. Soft and comfortable. The material is soft but flexible and usually requires a guidewire. It is less irritating to the urethra and bladder mucosa and has a higher biocompatibility, making it suitable for indwelling catheterization and irrigation care (usually 3-5 days).

Extra-hard evacuation type. Higher hardness and toughness is not easy to fold, suitable for cases where urine collection and catheterization are relatively difficult. Flushing is performed while catheterizing in order to evacuate the stone crystals present in the urethra in time. However, due to the high hardness, the affected pet is less sensible and is only used temporarily.