YOU SAID:

I have a dog and a cat but they are stupid

INTO JAPANESE

私は犬と猫を持っていますが、彼らはばかです

BACK INTO ENGLISH

I have a dog and a cat, but they are stupid

INTO JAPANESE

私には犬と猫がいるが、彼らはばかだ

BACK INTO ENGLISH

I have a dog and a cat, but they are stupid