SimGuruSarah has taken to Twitter to answer questions from players regarding pet aging in The Sims 4 Cats & Dogs Expansion Pack. She explains that if you disable aging for Sims in the game, then it will also disable aging for pets. Additionally, we won’t be able to manually age up pets in the game either, so they will have to age naturally.
UPDATE: SimGuruSarah has clarified her comments on Pet aging
If you have auto-aging off you can age up your pets with a special vet clinic treat you can buy (or make). https://t.co/aDOsWkNDFX
— Grim Grue Daniel (@SimGuruDaniel) October 12, 2017
If you disable aging for your Sims then it will also disable aging for Cats & Dogs.
— Sarah Holding (@SimGuruSarah) October 10, 2017
You cannot manually age Pets up. They will age naturally.
— Sarah Holding (@SimGuruSarah) October 10, 2017
They share the same settings with Sims.
— Grim Grue Daniel (@SimGuruDaniel) October 9, 2017