Whilst other collars will not impair the effectiveness of ADAPTIL® Collar, it is important to ensure that the ADAPTIL® collar remains in close contact with the skin and is not covered by any other collar or bandana. If ADAPTIL® Collar is covered or if ADAPTIL® Collar is not in continuous contact with the dog’s skin, the release of the pheromone may be compromised and the positive influence on your dog reduced.