If you are using MCCC and have adjusted the motive decline to a lower setting for cats and dogs, any other mod that alters a pet's moods, needs or actions, will not work properly in some cases. If you are using MCCC, reset the motive decline back to the default 100. If you do not use mods you should try resetting your pet with 'testing cheats' on. Before repairing your game through Origin make sure you delete your 'localthumbcache' because repairing the game will bypass that cache and any prolems you have will not be changed during the repair session. After that, if your pet is still falling over from exhaustion, try moving the family out of their current lot then move them back in. That will sometimes reset any afflicted family members. I hope this helps.
