In Japan, there are people who give their dog commands in English and people who give their dog commands in Japanese.
この場合、次のような言い方ができますよ。
ーIn Japan, there are people who give their dog commands in English and people who give their dog commands in Japanese.
「日本では、犬に英語でコマンドをする人と、日本語でコマンドを出す人がいます」people who give their dog commands in English/Japanese で「犬に英語/日本語でコマンドを出す人」
ご参考まで!