I have not read the book but presume it is referring to dog-human dominance.

I tend to think that we are too quick to ascribe the label 'dominant'. It is a convenient, fashionable, blanket term that is frequently used inappropriately to explain the cause of too many types of unwanted behaviour from puppy mouthing, lead pulling, etc. through to fear-biting. Dominance is not usually the cause of problem behaviour, but is the effect of poor training, lack of socialization, etc. It is therefore likely to be a learned response rather than an inherent characteristic.

I believe that the dominance theory, as I understand it, has merit when applied to interactions between dogs, but I am very sceptical when it is applied to the relationships between dogs and people. I fail to see how any dog can dominate a human unless it is permitted to do so. A dog needs leadership. It needs to be shown the acceptable boundaries and to have confidence in its owner. If we fail the dog in this regard then confusion and conflict occur.