Instead of Poochyena like in RS, in E there is a Zigzagoon. Does the Zigzagoon offer more exp?
I just tested this on Ruby and Emerald, and the Poochyena battle in Ruby gives you 15 experience points, and the Zigzagoon battle in Emerald gives you 17 exp.
So there's your answer, Zigzagoon offers slightly more exp!
Another way to see which one gives more EXP is to check the Pokemon's base experience yield. As you can see here, Zigzagoon has a base experience yield of 60 in Gen III-IV, and Poochyena has a base experience yield of 55 in Gen III-IV, meaning Zigzagoon will give more experience.