animal companions: does size increase with hd increase?

[Korin Tempest]

in advancing an animal companion, would it's size increase when it's new hd equals/surpasses the point where a normal creature of it's type would increase in size?

 

[Laurel]

Another Player interested in ideas/thoughts on this one

in advancing an animal companion, would it's size increase when it's new hd equals/surpasses the point where a normal creature of it's type would increase in size?

I'm playing my first druid/ranger. I have just been keeping the companion at the same size... but would love to hear what other people say.

 

[Shadeus]

An animal companion doesn't get bigger when it adds extra Hit Dice for the master's levels. The advancement entries for creatures, and the rules for advancing monsters, refer to unusually powerful specimens that are simply tougher (and perhaps bigger) than normal for their kind.

Straight from the FAQ on the WotC web site.