God put dogs on Earth to be a helper to humans. Our evolution as a species and our struggles into nature would have been difficult if not impossible without them. Our continued survival depends on them.
Many years ago I read that American Indian lore tells how man and dog became so close. The Creator set about populating the earth with all the creatures, animal and man, male and female. When He was done, He caused a huge fissure to open up in the Earth, forever separating man from the animals. But while the Creator had been going about His task, the dogs and humans had come to trust one another and become friends. The dogs were distraught to see the Earth slowly opening up, separating them from mankind. They paced back and forth until, at the last possible moment, they leapt across the chasm and were reunited with their new friends. Dogs and mankind have been devoted to one another ever since.