Nature is really very surprising. I have a watermelon plant growing opposite to my house. I see dogs eating the leaves of that watermelon plant. I have been observing this for the past few days. Dogs one after the other visit this plant and take a bite. These are some of the leaves that even cow or other plant eating animals don't eat.
Dogs are one of the sharp species and even sharper than humans in certain aspects. With just a sniff they know what to eat and what not to eat. Looks like watermelon leaves are some kind of medicine for them. That's why they are eating it. Otherwise dogs don't usually eat plants. Amazing nature.
I really wish humans had powers like this to find out which food is good for us and which is not and what we need at what time. Especially medicines. Maybe we would have had that power too but as part of evolution, we have forgot this skill. But there are still people and medicinal practitioners who can tell the properties of a root with just a sniff. They know with the smell that healing capabilities that a root can have.