Why do small dogs live longer?

Kraus speculates that because large breeds grow faster and age quicker than small breeds, that abnormal cell growth found in cancers would be more likely. Another possibility is that larger dogs start aging at an earlier age, thus developing age-related diseases earlier. read more

This is certainly the case for dogs, and scientists think that the reasons big breeds die young have to do with the way humans have bred them and the way they grow. Larger dogs grow very big very fast. Take a one-year-old Great Dane, for example. It’s huge. From birth to their first birthday, they increase 100-fold in weight. read more

It’s strange that across species, at least in mammals, large-bodied animals live longer than small-sized animals. For example, elephants live a lot longer than mice. The theory is that bigger animals have slower metabolisms than small animals, and that faster metabolisms result in more accumulation of free radicals that damage tissue and DNA. read more