The correct form of the verb is 'likes': Sheila likes dogs. In English, verbs in the present simple take a final "-s" for the third person singular (he, she or it) in the affirmative form. Sheila could be replaced by the pronoun "she" so the verb must have a final "-s". Notice that, if the sentence was negative or a question, the verb would not have the final "-s" and in the sentence you should add "doesn't (or does not) for the negative/"does" for the question, which function as auxiliary verbs, before Sheila:
-negative sentence: Sheila doesn't like dogs.
-question: Does Sheila like dogs?
likes is the write answer, however when peoplespeak many of them say like insead of likes