1. They raise popular pets,e.g. cats and dogs.

(How do you read "e.g." in English?)

The abbreviation "e.g." is for the Latin phrase exempli gratia, meaning "for example."

Therefore, when reading such a sentence aloud, you can either speak those letters (eee gee) or you can say what they stand for -- that is "for example." Just remember spacing after punctuation when you're writing sentences.

Say, "They raise popular pets, e.g., cats and dogs."

The usage notes here are interesting and may be helpful:
http://en.wiktionary.org/wiki/e.g.