Dogs are equipped with teeth. They have them. Anything with teeth is a bite risk in the right circumstances. All dogs, cats, lizards, my aunt Jamie.
In the right circumstance any dog will bite. No matter how careful you are, accidents can still happen. You can be doing work in your yard with a reactive dog and have a stray rush you and the initial dog redirect onto you.
Some dogs have very high thresholds. For example, Nora can be at the vet, having blood drawn, and restrained and it doesn’t put her at her bite threshold.
But Noah, a partially sighted dog, would bite at anything that startled him, including people, shadows, and stationary objects. This dog made tooth to skin contact on several people, including me, especially when he initially arrived at the shelter.
It is a continuum and different for every dog. What drives one person’s dog to bite, might not affect someone else’s dog at all. There are plenty of signs of stress that usually accompany a dog approaching their bite threshold. Including pinned ears, whale eyes, tight lips, panting, and avoidance.
So many people (especially older people in my experience) have the attitude that dogs should tolerate anything done to them with peaceful equanimity no matter how anxious, uncomfortable, painful, or traumatic it may be. We would never expect the same of other humans. Just like us they have different personalities, backgrounds, and genetics. Some are very sensitive and flighty, some are super chill and unfazed by a lot of stimuli. It’s up to us as their guardians and caretakers to treat them as individuals and to at least try to gain some understanding of the way they individually communicate their signs of discomfort or anxiety.