Pets are an important part of the Sims 4 experience, and they can add a lot of fun and companionship to your Sims' lives. However, pets don't live forever, and eventually, you'll need to age them up in order to keep them around. Here's how to age up a pet in Sims 4:

How to Age Up a Pet in Sims 4

Steps

1. Make sure your pet is ready to age up.

Pets can only be aged up once they have reached the "Young Adult" stage. This usually happens when they are around 24 days old. You can check your pet's age by clicking on them and selecting "Check Age."

2. Build a birthday cake.

Pets can only be aged up by eating a birthday cake. To build a birthday cake, you will need the following ingredients:

- 1 Carrot - 1 Flour - 1 Sugar - 1 Egg - 1 Milk

Once you have all of the ingredients, click on a stove or oven and select "Bake." Then, select "Birthday Cake" from the list of recipes.

3. Give the birthday cake to your pet.

Once the birthday cake is finished baking, click on it and select "Give to Pet." Your pet will then eat the cake and age up to the next life stage.

4. Enjoy your pet's new life stage!

Once your pet has aged up, they will have new interactions and abilities. You can also change their appearance and name if you want.

Troubleshooting

1. My pet is not eating the birthday cake.

If your pet is not eating the birthday cake, it may be because they are not hungry. Try waiting until your pet is hungry before giving them the cake. You can also try clicking on the cake and selecting "Force Pet to Eat."

2. My pet aged up to the Elder stage and died.

Pets can only live for a certain number of days. The maximum lifespan for a pet is 130 days. If your pet aged up to the Elder stage and died, it is because they had reached the end of their lifespan.

3. I don't want my pet to age up.

If you don't want your pet to age up, you can use a cheat code to stop them from aging. To do this, open the cheat console by pressing Ctrl + Shift + C. Then, type the following code:

``` cas.fulleditmode ```

This will allow you to edit your pet's age. You can then set their age to whatever you want.