It is very good to save or help any animal including dog and pig. We have a Hadeeth about a sinner who was entitled to go to hellfire but was saved from hellfire just because he gave water to a thirsty dog. There is also a Hadeeth about a Muslim woman wo will go to hellfire just because of a cat which was locked up by her and left with out food and water. It is always very good to help, feed, give water to any animal.
Touching wet dog or wet pig will make your hand or body Najis, and that will never harm you as it can be purified with water.