Story of the Rainbow Bridge or what happens when we say goodbye to our pets

I have a senior dog. How to recognize pain? Old Age isn't loud and flashy like an influencer in need of attention. Old Age comes slowly. Silently. Step by step. One day you notice more greys on their head. They still get excited about daily walks, but those walks tend to last longer. Maybe you will even hear that treacherous sound of one paw "scratching" the pavement with the nail. Also, the house becomes more quiet. Because that little grey head sleeps more. You don't p