It is not only Jewish people who are commanded to rest on Shabbat; their animals may also not work. The Sages relate a story of a gentile who bought a cow from a Jew. Since it was accustomed to rest on Shabbat, the cow was unwilling to work on Shabbat.

Our Sages said: There was an incident involving a certain Jew who had a particular cow that plowed. His financial situation worsened and he sold it to a certain gentile. When the gentile took it, he plowed with it on the six days of the week. On Shabbat he took it out to plow with him and it crouched under the yoke. He continually struck it, but the cow would not move from its place. When he saw that this was the case, he went and said to the Jew who had sold it to him: Come, take your cow, perhaps it is ill, as no matter how many times I strike it, it will not move from its place.

That Jew realized that it was because of Shabbat, as the cow was accustomed to rest on Shabbat. He said to the gentile: Come, and I will cause it to stand. When he arrived, he said to the cow in its ear: Cow, cow, you know that when you were in my possession you would plow on the days of the week and you would rest on Shabbat. Now that my sins have caused my poverty and you are in the possession of a gentile, I implore you to stand and plow. Immediately, it stood and plowed.

That gentile said to him… I will not leave you until you tell me what you did to it in its ear. I exhausted myself striking it and it would not stand.

That Jew began placating him, and said to him: I did not perform sorcery or witchcraft. Rather, this is what I said in its ear, and it stood and plowed. Immediately, the gentile grew fearful and said: If a cow, which cannot talk and has no understanding, knows its Creator, I, who was formed by my Maker in His image, and He instilled knowledge in me, shouldn’t I go and know my Creator? Immediately, he went and converted, studied and attained the Torah, and they would call him Yohanan ben Toreta, and to this day our Sages cite halakhot in his name. (Pesikta Rabbati [Ish Shalom] 14)