My definition would be a dog doing what it loves to do, going for walks on the beach or in the woods, splashing in streams, chasing the mailman or sniffing any dogs it meets, guarding the house, following its owner around in the house hoping for a tidbit to drop or a pat on the head or acknowledgement that you know they are there. In other words letting you know that they are very important and are part of the family!
What happens when it loses the ability to walk and do all its favorite things? Very often depression, no more bright eyes and tail wags and no more being able to go on walks with the other members of the family, either canine or human or chasing balls or keeping the property safe from intruders.. Very often they become totally paralyzed due to disc problems, strokes, an embolism or accidents. This in turn makes us depressed and very often not knowing what is best for our pet as we do not want to see them in this condition.
Depending on what is causing the lack of mobility, your veterinarian may be able to reverse the condition or in the case of older dogs may be able to help medically or recommend a rehabilitation program or acupuncture.
We at K9 Carts have been bringing K9 happiness to thousands of dogs over the last fifty years. I have personally been helping them for 38 years and I can tell you a I still get a wonderful feeling of happiness every time I fit a dog to a cart and watch its tail wag and eyes brighten as it realizes that it can be a "dog" again and I love receiving emails and videos from owners letting me know how happy their pets are and how happy they are seeing them enjoying their renewed mobility. With our orthopedically balanced cart it keeps them mobile longer and keeps stress off the rest of their bodies and especially their front legs. I just wish over all these years, I had kept count of how many pets returned to full mobility on their own with the aid of our dog wheelchairs!