is the item your referring to hurricane?

yes

and good riddance---it was needed, especially on something that has little counterplay (there's absolutely no way to counter shrooms in a bush other than placing a ward+having oracles or placing a pink ward).

Wrong, Toxic Shot has two parts, the onhit damage and the poison thicks. the total scaling was down from 0.8 to 0.7, its a 12%-ish reduction on the total scaling.

Also, AP teemo endgame could do 400 magic damage on hit to 3 targets at same time with an at least 1.7 attack speed, and while that he aplied malady making himself and the ap carry hurt a lot more (about about 70 magic penetration + shred on Teemo with Liandry and magic pen runes+boots+mastery).

Season 3 Teemo had damage equivalent to an adc if you split his damage between the team (each shot doing almsot 1200 damage between 3 people in best case scenario), plus the oracles nerf makes his shroons much stronger.

400 magic damage? what are you smoking? grabbing Hurricane takes up a slot so he doesnt have the AP to deal close to that damage.
Liandry only applies to his shrooms and blinding dart, and deals % of current health not max health.
I personally dont care about the poison damage, i want to kill my target before it kills me, so i care about the on-hit damage the most.

I think that there was a way simpler way to fix this. Make it so hurricane doesnt proc his skills. As technically its not an on hit effect, but an on hit skill.

And his mushrooms being nerfed (while somewhat needed) should also be put into perspective on how badly they nerfed oracles now. Oracles only lasts 5 minutes or until death unlike the old oracles that lasted only until death. Personally i didnt have an issue with the old oracles but i understand why they removed it. Personally im not going to bother with oracles unless going on a ward clearing spree everywhere on the map as any other time and its almost not worth it. It would be better just to grab a vision ward 75% of the time now. Oracles because it was nerfed means you cant clear teemo mushrooms all game. So yes. I dont mind the mushroom nerf as it was needed.

and spellshields and yorick and lulu and lee sin and morgana and mr and healing and knowing where a teemo will shroom

Never thought I'd see the day where Teemo got nerfed.

In celebration, I'll leave you with this: http://www.youtube.com/watch?v=MdN0NXgjsn8

*Still hates Teemo with a aburning passion*

Teemo needed to be nerfed and have his strength shifted, currently he is almost game breaking in dominion.