It's pretty easy to assume that a character with 26+ INT could come up with the correct wording, even if you and I can't.
Good point.
So it's probably better to focus on the OP's original questions, can a Wish turn a person into an animal? Would you restrict the INT to 2?
Okay, let me turn this question around to illustrate my position.
Let's assume someone wants to turn into the undead type for whatever reason (it's a lot more attractive than being an animal
http://www.dandwiki.com/wiki/SRD:Undead_Type) but doesn't want to change in any other way than that.
But what does being an undead entail apart from those numerous perks? Would he be immortal? Infertile? Rotting away or ageless? Would he be able to fulfill a prophecy that states that "no living man can ever yadda yadda yadda", if he wouldn't actually BE undead apart from a purely game mechanic PoV?
In other words: Would an undead that behaves in any other way apart from the game mechanics like a living being actually be conceivable?
Can a wish "invent" something totally new for a game world or produce a result that totally runs counter to the in-universe logic?
Or would it be much more feasible to make the player in the TE's group come up with a workaround that produces the results in regards to game mechanics, but doesn't try to stick to the original goal of getting the animal type.
(assuming this isn't just some kind of intellectual exercise in the first place, since I fail to see why becoming an animal is a desirable goal)
For that matter, if someone stuck a hat of +4 INT on a dog, would you say "it doesn't work" or would you say "it now has a 5 (or 6) INT?
Interesting question.
Would you let a cat benefit from the perks of a (large) magic ring worn around its paws, or would you restrict the benefits only to magical items that are explicitly tailormade for animals? And, the other way round, would you let a humanoid being benefit from that kind of item, f.ex. let a human benefit from wearing horseshoes under the sole of his shoe (I don't even know whether unicorns may benefit from magical horseshoes) ?