Caliban said:
Those were all part of the creature when it was summoned, they would all leave with the creature when it leaves.
Caliban, I understand what you are saying, but I have to respectfully disagree. For certain things such as armor and weapons, I agree that they would go back with the summoned monster. For instance, no summoning an Astral Deva, instructing him to fork over his magical mace and then selling it for a profit.

However for poisons and disease I can't really agree. I mean what's the point of summoning a fiendish viper if your enemies won't be around to take the secondary poison damage?