YOU SAID:

my dog is tripping on nothing

INTO JAPANESE

私の犬は何もつまずいていない

BACK INTO ENGLISH

My dog hasn't stumbled on anything

INTO JAPANESE

私の犬は何にもつまずきませんでした

BACK INTO ENGLISH

My dog didn't stumble on anything

INTO JAPANESE

私の犬は何にもつまずきませんでした

BACK INTO ENGLISH

My dog didn't stumble on anything