Amjoie - you did a no-no that is too many sims in that household - you coulkd have had the 8 sims but no horse as horses, dogs, and cats are considered sims in Sims 3. I suggest you re-start the game because backing up may not fix the corruption. I am actually surprised the game even let you place those 4 sims - but it could be the twins factor - as in there was a chance that a family with 7 members could have a pregnancy with twin for an eigth baby - but when it happened most generally before those kids reached either child or teen age the game would corrupt because they were getting too close to the 8 YA and up sim to a household limit. Because of this one of the patches - I believe it was the Generations one, stopped a sim from having twins or higher if 7 were already in the household - but it might have been messed up with the new head count for Pets that at one point was allowing a 10 count of 6 human and 4 animal sims in a household. People thought it meant with Pets they could have 10 family members regardless of the combination as long as a few were pets - but that is not true - the game programing says you can have either 8 sims with no pets or 6 human sims with up to 4 pets. So how you transended to 8 humans and 1 animal I am preplexed as that should not have been possible - so it is my only deduction your game was corrupted right prior to you doing that - and seeing that corruption involves breaking the actual programming you really need to get rid of that save and start all over otherwise you are going to incompass further corruption.
