If human products are considered unnatural, dogs must be so too. Dogs did not occur in nature; we manufactured them out of wolves. To be our friends.
Some of the latest dog research I've seen is just incredible. Did you know that we are now training dogs to sniff out cancer? True story. Just like the singular smell of cadavers, cancer in humans can be picked up and signaled by trained dogs. Pretty neat.
I contracted strep throat. I went to the doctor. I hate the throat swab worse than anything, seriously. The culture was positive for STREP; so she wrote me a prescript for antibiotics.
I got rid of it, but somehow contracted strep again after three weeks. I went back to the doctor, and told the receptionist I didn't want the throat swab. She implied I would probably still get one.
So why don't you have the same relationship with your body? People exercise to look good, not for future health. You can look around and know that as you age, your body will begin to break down. First you lose the ability to jump and run. Then your balance gets weaker. Then you become prone to injuries.
But when I read about some doctor suggesting seniors should lift weights, I throw up a little in my mouth. They don't call 'em DUMBELLS for nuthin'.