For those who may have or have not already been informed, Mod The Sims Member Sims MX, has found that the patch contains files regarding Pets. You can check there for how they found the file as I will not be releasing that info here.
With the help of Sims3Cri, we have a complete list of all the features from this game file regarding Pets! This is a spoiler, therefore you will need to continue on to the full page link below to see all the information. Some of you may not want to spoil it for yourselves!
♦ Please note that the info from this file is subject to change as this is an Expansion currently in development. The information listed here is most likely incomplete and/or will/may be changed before the game release.