The problem of obesity isn’t confined to just humans. A new study finds increased rates of obesity in mammals ranging from feral rats and mice to domestic pets and laboratory primates.
[...]
“We can’t explain the changes in [the animals’] body weight by the fact that they eat out at restaurants more often or the fact that they get less physical education in the schools,” Allison told LiveScience. “There can be other factors beyond what we obviously reach for.”
Without recommending the specific article, but to give a source: http://www.livescience.com/10277-obesity-rise-animals.html