Siman 523

We conclude in the Gemara (23a) that it is permitted to scrape and curry an animal. Rashi explained that this refers to scraping the animal with a scraper; "scraping" refers to an iron scraper, which might cause a wound. Nevertheless, we are not concerned about it, for an unintended act is permitted. "Currying" refers to a wooden scraper that cannot cause a wound, and it must be done in a manner where there is no concern of pulling out hair. For if there is a concern, such as with our combs—it is obvious that it is forbidden, as it is a pesik reisha, just as it is forbidden to comb the head with a comb. And so wrote the Tur, that with our combs it is a pesik reisha and is forbidden, see there, and so wrote the Shulchan Aruch.

The Rambam in the Commentary on the Mishnah, and likewise the Aruch, explained another explanation: that we are not dealing at all with the plucking of hair, for that is certainly forbidden. Rather, this is its explanation: that there are flies that cling to the thighs of the animals and stick to them, and some of them are small, and when one removes them – it is possible that a wound will be made. And there are large ones where there will not be a wound. Therefore, it is permitted even with the small ones, because this is a matter that is unintentional. And I do not know how they permitted the handling of the flies, for they are muktzeh. And it is possible that they permitted it because of the suffering of living creatures. Or it is possible that they handle them by means of another object, and it is handling from the side for the sake of a permitted thing, that is to say, for the sake of the animal which is a permitted thing. And so it appears to me to be the primary view.

One may not deliver the offspring of an animal on Yom Tov. However, one may assist it, such as by holding the newborn so that it does not fall to the ground. And even though it is forbidden to slaughter it today, and it is therefore muktzeh—nevertheless, they permitted it because of its great pain. Furthermore: if its months of gestation were complete, one is able to slaughter it today. And one may blow into its nostrils and place the teat into its mouth. Regarding an animal that has distanced its offspring—it is permitted to sprinkle the fluid of its placenta upon it, and to place a fistful of salt into its womb, so that it will have compassion for its offspring. For an impure animal one should not do so, for an impure animal does not distance its offspring, and if it does distance it, it will not draw near again (Shabbat 128a). And the fluid of the placenta is certainly muktzeh. Nevertheless, they permitted it due to pain, or perhaps by means of something else, as I wrote in the previous section.