Using a harness and a collar at the same time is a great idea because the harness is safer to use and more comfortable for your dog while the collar can be used to carry your pet’s identification tags. These tags usually contain the dog’s name and your contact details that are useful if, God forbid, your dog gets lost. Harnesses are also excellent when you want to train your puppy. Attaching the leash to a harness is much safer and more secure during training sessions because it won’t allow the leash to strain your dog’s neck. Also, your Frenchie won’t be able to slip out of the harness like they could when using only a collar.