The most I give mine is a spoonful.
The first time, I split the can between them and gave it to them each on separate plates. They loved it so much that they both inhaled it (it was gone within 10 seconds). Wesley was fine (he's 10 pounds), but Maddie (she's 6.5 pounds) ended up throwing hers up a couple of minutes later. I had to pick it up quick before she tried to re-eat it. I know, totally gross.
So now I only give them a spoonful each. I let them lick the spoon, then I hold it back for a couple of seconds, then give them another lick, etc... so they can't eat it so fast. Plus it makes the can last a little longer.