One the the FAQ’s & concerns about the Sims neighborhood is the household limit through Pets. This day we have our answer evidenced via 
Gamescom 2011.

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The Sims 3 Pets growth has bumped the family members limit by 2 totaling 10 members. This way you have the right to mix and match in between 8 Sims and also 6 pet that execute not exceed 10. Pets will certainly count as member of the household and also take up a spot.

Note that just Playable pet (Dogs, horses & Cats) take it up a clues in a family panel. Lizards, Birds and other collectible pets can be obtained by the dozens. (assuming girlfriend have enough money)