SELECT pet.*
     , ownrs.id AS ownrunique
     , ownrs.super
     , ( SELECT COUNT(*)  ,MAX(comments.comDate) AS lastCom  /* Trying to add a new field here (how to select multiple columns here) */
         FROM comments
         WHERE pet.id = comments.petid
       ) AS noOfCom
     , ( SELECT COUNT(*)
         FROM petfb
         WHERE pet.id = petfb.petid
           AND feedback IN (1, 100)
       ) AS newLikes
     , ( SELECT COUNT(*)
         FROM petfb
         WHERE pet.id = petfb.petid
           AND feedback IN (5,10)
       ) AS newDisLikes
     , ownrs.name
FROM
        ( SELECT pet.*
          FROM pet
          WHERE catid = 21
          ORDER BY `lastCom` DESC  /* Sort order needs to be changed. */
          LIMIT 0, 10
        ) AS pet
    INNER JOIN
        ownrs
            ON ownrs.uniqueID = pet.ownerID;
/* ORDER BY removed from here; Seems not required. */