Cocker Spaniel

These cute pups are known to be very high-energy dogs, yet what most owners do not know before they get a cocker spaniel is the fact that they do have a penchant for eating way more than they should. This means that you cannot free feed a cocker spaniel, as instead of eating only when they are hungry, they will end up eating everything you put in front of them with no questions asked.

What’s more, they are a breed that is known to be prone to developing hypothyroidism. This disease causes their bodies do not produce enough thyroid hormones, which are supposed to help keep their weight in check. Couple this disease with the fact that they love food and are potentially not getting enough exercise, and you can have an overweight dog seemingly overnight!