Dogs can wear collars during the day for identification and leash-walking purposes. However, it's essential to remove collars during unsupervised periods and at night. This practice prevents potential accidents or collar-related issues, like choking hazards or discomfort. Additionally, using a comfortable, breakaway collar with an ID tag is recommended to ensure safety while giving your dog some collar-free time for relaxation. Always prioritize your pet's comfort and safety when deciding when to have them wear a collar.