I feel like there is very little information out there about how to properly fit a dog to a harness.
All the different brands talk about how their harness is no-pull, comfortable, breathable, and adjustable. There are many brands I would not recommend and a few I would but I don't know all the brands in the world so I put a harness fitting tutorial together to help you be more mindful about harness mechanics. Consider how different shapes and fits might pinch or rub your dog's body making the harness uncomfortable for extended use throughout the day.
Keep in mind harnesses should be put on for use when you intend to take them for a walk, train, or otherwise need a harness on the dog for that activity. Then take it off for down time in the house. There has been some conversations recently in groups I'm part of talking about body bruising caused by harness buckles on the dogs rib cage. Mainly caused by dogs wearing harnesses for prolonged periods of time and being force to sleep in the harness. Especially problematic when the dog sleeps on a hard surface, like a puppy in a crate without bedding.
Ask yourself a couple of questions when it comes to the use of equipment like a harness:
Does it look comfortable to you? Or if you were moving, sleeping, or living in this equipment does it pinch, push, or rub on parts of the body?
Can you think of any possible scenarios where this equipment could become a hazard to the dog? Consider taking the harness off during times of activity where the harness could be dangerous. Sometimes no equipment is the safest option for dog-dog play time or running in the woods.
Please enjoy the educational video and let me know in the comments what equipment you want me to review next.
Also, do you use a unique brand of harness? What do you have your dog wear and what do you like most about it? We can make the comments an item review place for those looking to get a new harness.