Originally Posted by
TubeDriver
First, What kind of plant? Toxic?
Secondly, it is possible he injured himself on the door. He could have bruised himself, perhaos even an organ like a stomach. The most important thing is to watch for any signs of internal bleeding. Keep track of his urine and poops. Watch out for any blood, it could look like typical red blood or more darkish, almost like black tar.
The round dot could be a blot clot caused by the trauma of hitting the door. If it is right under the skin, it will probably resolve on its own in a couple weeks (body slowly absorbs it over time).
In the short term, I would just hydrate him well and watch him carefully for any symptoms.