The dog's urinary catheter hair does not need to be trimmed. The urinary catheter hair can protect the dog's reproductive organs from friction and infection, avoid causing other diseases, and can also prevent urine from staining the surrounding hair. If the catheter hairs are too long or bifurcated, they can be trimmed appropriately, but they must not be cut off entirely, and the catheter hairs need to be cleaned frequently to avoid the breeding of bacteria.