Pets are a beloved part of the Sims 4 experience, adding furry companions to your virtual household. However, as Sims progress through their lives, their pets do too, and eventually, they reach the end of their lifespan. While this can be a bittersweet moment, you can also age your pets up manually to keep them around for longer or to progress their life stage.

### Using the Birthday Cake

1. Purchase a Birthday Cake: Head to the "Objects" section of Buy Mode and search for "Birthday Cake." You'll find various cake options, so choose one that suits your pet's personality.

2. Place the Cake: Place the birthday cake on a flat surface, such as a kitchen counter or dining table, where your pet can easily access it.

3. Have Your Pet Eat the Cake: Click on the birthday cake and select the "Have (Pet's Name) Eat Cake" option. Your pet will happily munch on the cake and enter a special animation.

4. Age Up Your Pet: Once your pet finishes eating the cake, they will age up to the next life stage. You'll see a notification indicating that your pet has aged up.

### Using the Pet Treat

1. Purchase a Pet Treat: Open the "Objects" section of Buy Mode and search for "Pet Treat." You'll find various treats available, so choose one that your pet likes.

2. Give Your Pet the Treat: Place the pet treat on the ground or in your pet's inventory. Then, click on your pet and select "Give Treat." Your pet will eat the treat and receive a mood boost.

3. Age Up Your Pet: After your pet eats the treat, they will age up to the next life stage. You'll see a notification indicating that your pet has aged up.

### Using the Cheat Code

1. Enable Cheats: First, you need to enable cheats in The Sims 4. To do this, press "Ctrl" + "Shift" + "C" simultaneously to open the cheat console.

2. Enter the Cheat Code: Type in the following cheat code into the cheat console: "cas.fulleditmode" (without the quotation marks) and press "Enter."

3. Open the CAS Screen: Once the cheat code is entered, hold down the "Shift" key and click on your pet. This will open the Create-A-Sim (CAS) screen, allowing you to edit your pet's appearance and age.

4. Age Up Your Pet: In the CAS screen, you can manually age your pet up to any life stage. Simply click on the "Age" option and select the desired life stage.

5. Save Changes: Once you're satisfied with your pet's new age, click the "Save" button in the bottom right corner of the CAS screen to confirm the changes.

How Do You Age Up a Pet in Sims 4?