SELECT p2.DbId, p2.happiness, p2.user_DbId  FROM `pet` AS p2  WHERE p2.user_DbId =142;

+------+-----------+-----------+
| DbId | happiness | user_DbId |
+------+-----------+-----------+
|  482 |         0 |       142 |
|  484 |         0 |       142 |
+------+-----------+-----------+
2 rows in set (0.01 sec)


SELECT p2.DbId, p2.happiness, p2.user_DbId, count( p1.user_DbId )
    -> FROM `pet` AS p1
    -> JOIN pet AS p2 ON ( p1.user_DbId = p2.user_DbId )
    -> WHERE p2.user_DbId =142
    -> GROUP BY p1.user_DbId;
+------+-----------+-----------+-----------------------+
| DbId | happiness | user_DbId | count( p1.user_DbId ) |
+------+-----------+-----------+-----------------------+
|  482 |         0 |       142 |                     4 |
+------+-----------+-----------+-----------------------+
1 row in set (0.00 sec)