Because melon seeds contain a lot of salt and sugar, if dogs eat food containing a lot of salt, it will cause kidney problems, and the use of sugary food will also affect the dog's absorption of calcium.

At the same time, when eating melon seeds, saliva will be lost and spit out because it adheres to melon seeds. Excessive saliva loss will lead to oral ulcers, gingivitis, dental caries, indigestion and other diseases, but also dull taste and loss of appetite.

Extended data:

Dogs sometimes eat grass, but they eat very little and occasionally spit it out. Dogs eat grass not to satisfy their hunger, but to clear their stomachs, mainly because of their unique gastrointestinal structure. The dog's stomach is very big, accounting for about 2/3 of the abdominal cavity, but its intestines are very short, accounting for about13 of the abdominal cavity. Therefore, dogs basically use their stomachs to digest food and absorb nutrients. It is easy to digest meat food, and it is difficult to digest things with "tendons" such as leaves and grass. Although dogs are carnivores, they can eat vegetables and grains when they are in trouble.

Typical wild carnivores' dietary nutrition comes from the stomach contents of herbivores they capture. In addition, scientists have also found that high-protein foods (eating a lot of meat) can help them prevent muscle tissue damage, such as the dog sled race in Idatarod, Alaska, and other similar situations under extreme pressure.

Baidu Encyclopedia-Dogs (Taboo Diet)