According to the Mishna on today’s daf if someone rents a donkey from his friend and it is taken as an angarya the owner can simply tell him that it is his responsibility and loss. If, however, the donkey dies or breaks a leg, then the owner is obligated to replace the animal according to their agreement.
An angarya is temporary forced labor that someone may be called upon to do for the king. It was fairly common for the king’s men to force laborers to leave their normal work and participate in various public works. Similarly, animals were taken for such projects, often together with their owners. Depending on the historical period, there were also times when animals were taken for longer periods of time, or were even kept and not returned to their master.
The Gemara quotes Rav as ruling that the halakha of the Mishna freeing the owner from replacing an animal that was taken for angarya only applies if the animal was taken for a relatively short period of time. If the animal would not be returned, then the owner would be obligated to offer a different animal to the renter. Shmuel disagrees, arguing that we are not concerned with whether the animal will be returned. The crucial point according to Shmuel is whether or not the animal was taken be-derekh halikhatah – literally, was the animal taken in the way it was going.
Rashi explains that the angarya ordinarily would take an animal along the road and return it to the owner immediately upon chancing on a replacement animal. Therefore, if the angarya was traveling in the same direction as the renter, the owner can argue that he suffered no real loss from the angarya. Tosafot quotes Rabbeinu Hananel as offering a different approach. If the government is not actively looking for such animals, but the king’s men took it because they came across it on the road, the owner can claim that it is the renter’s fault. Had the animal stayed home, this would not have happened. If, however, the government is searching in homes, as well, the owner cannot lay the blame on the renter and he will have to replace the animal in order to keep the rental agreement.