Watermelon seeds are generally considered to be non-poisonous to most animals and are not harmful in the slightest to humans.Although there are a number of seeds in the world that are considered to be poisonous and even toxic, watermelons are not among them.

There are some animals with a diet that does not allow for many fruits or vegetables, such as cats and dogs. By giving watermelon seeds to smaller animals, you are risking them choking.

The best thing you can do is to refrain from feeding your pet watermelon seeds altogether and also avoid it yourself if at all possible, though they do not pose any direct threat to your health.