The past tense of spew is spewed. The third-person singular simple present indicative form of spew is spews. The present participle of spew is spewing. The past participle of spew is spewed or spewn.

Do you pat or pet a cat?

As for "pet" or "pat", both are correct. Pat connotes a light, quick stroke with the hand. She gave him a friendly pat on the arm. To pet an animal is to stroke or caress gently; pat; to touch or stroke in an affectionate or loving manner.

Can you say petted?

Is petted a real word? Yes, petted is a real word. In fact, petted is the correct past tense form of to pet.