YOU SAID:

I have a cat who is called tom

INTO JAPANESE

私はトムと呼ばれる猫を飼っています

BACK INTO ENGLISH

I have a cat called Tom

INTO JAPANESE

私はトムという猫を飼っています

BACK INTO ENGLISH

I have a cat named Tom

INTO JAPANESE

私はトムという名前の猫を飼っています

BACK INTO ENGLISH

I have a cat named Tom