The process begins at a level where the pet notices the stimulus but remains calm, then slowly increases intensity over days or weeks. For example, a dog afraid of vacuum cleaners might first see it unplugged across the room, then hear it from behind a closed door, then at increasing volumes and decreasing distances. Success depends on never pushing too fast. If the pet shows stress signals (panting, lip licking, freezing, trying to flee), the intensity was raised too quickly and should step back. Desensitization works best paired with counter-conditioning so the pet builds positive associations simultaneously. Professional guidance is recommended for severe phobias or aggression cases, as mistakes can sensitize the pet further.