The average lifespan of a dog is 10 to 20 years, depending on the breed and living conditions. According to some researchers, the average universal life expectancy of a dog is 12 and half years, although dogs usually go on living up to 15 years in modestly healthy living conditions. Vet care also matters in the life duration of a dog. Longest ever dog to live according to recent records was a Labrador cross, named Bella, which lived for 29 years and 193 days. Dogs of smaller breeds live longer compared to bigger breeds ones.

Various other factors also affect the live duration of a dog. Because of the diversity in species and crossing of breeds, there is no predetermined diet that could work the best for dogs keeping them healthy round the year. The living condition and diseases are also some factors that decrease the life span of a dog. As dogs age, they develop various weaknesses including reduced eyesight and hearing, loss or energy making them sleep most of the times during the day, decreased immune system, loss of teeth and skin related problems. However, eating healthy, proper vet care and life in a healthy and friendly environment makes them live longer than regular life spans.