Yes, leather dog collars can get wet, but it’s not recommended. Leather is a natural material that is susceptible to damage from water. When leather gets wet, it can shrink, stretch, and become misshapen. It can also become discolored or weakened. In addition, mold and mildew can grow on wet leather, causing it to deteriorate. If your dog must swim with a leather collar on, be sure to remove the collar as soon as possible and allow it to dry completely. With proper care, a leather dog collar can last for many years. However, if it becomes wet frequently, it will likely need to be replaced more often.