ABSOLUTELY NOT!!! Those who claim this to be true are those individuals who lack the proper knowledge and skills needed to fix the underlying issues. The fact is that state of mind of a dog is what matters. 2 dominant personalities, regardless of sex, who don't have the necessary leadership, directions, boundaries, and limits, will fight to see which one will be the pack-leader. That's why at Packman to the Rescue, we focus on providing our clients with the PROPER knowledge and skills that are truly needed to have a dog that is happy, fulfilled and well-behaved.