יורה דעה כ״הYoreh De'ah 25

Se’if 1א׳

הַשּׁוֹחֵט צָרִיךְ שֶׁיִּבְדֹק בַּסִימָנִים אַחַר שְׁחִיטָה אִם נִשְׁחֲטוּ רֻבָּן, אוֹ שֶׁיִּרְאֶה בִּשְׁעַת שְׁחִיטָה שֶׁהֵם שְׁחוּטִין רֻבָּן; וְאִם לֹא רָאָה שֶׁרֻבָּן שְׁחוּטִין, אָסוּר. הַגָּה: וְנָהֲגוּ לִבְדֹּק בְּדֶרֶךְ זֶה, שֶׁתּוֹקֵף אֲגוּדָל עַל שִׁפּוּי כּוֹבַע וּמִתּוֹךְ הַדַּחַק יִפָּלְטוּ הַסִּימָנִים לַחוּץ, וְאָז יָכוֹל לִרְאוֹת אִם נִשְׁחֲטוּ רֻבָּן, גַּם אִם עֲבִיד שְׁמוּטָה, כִּי אִם לֹא יִכָּנְסוּ הַסִּימָנִים לִפְנִים לְאַחַר שֶׁהֵסִיר אֶצְבָּעוֹ, הֲוָה שְׁמוּטָה וּטְרֵפָה (הַגָּהוֹת בִּשְׁחִיטוֹת). מִיהוּ, אֵין צָרִיךְ לִבְדֹּק אַחַר שְׁמוּטָה, דְּסָמְכִינָן אָרֻבָּא כְּמוֹ בִּשְׁאָר טְרֵפוֹת; וְיֵשׁ מִי שֶׁאוֹמֵר שֶׁצָּרִיךְ לִרְאוֹת שֶׁהֵם שְׁחוּטִין בִּמְקוֹם שְׁחִיטָה בְּלֹא הַגְרָמָה. הַגָּה: וְיֵשׁ לִבְדֹּק אַחַר זֶה קֹדֶם שֶׁיִּזְרֹק הָעוֹף מִיָּדוֹ (מהרי"ק שֹׁרֶשׁ ל"ח בְּשֵׁם שְׁחִיטוֹת אַשְׁכְּנָזִים) ; אֲבָל אִם לֹא בְּדָקוֹ תְּחִלָּה, בּוֹדֵק אַחַר כָּךְ וְלֹא חַיְישִׁינָן שֶׁמֶּא עַל יְדֵי הַפִּרְכּוּס נִתְרַחֵב הַחֲתָךְ (סְבָרַת מהרי"ק שָׁם).

One who slaughters must examine the simanim — the windpipe and the gullet, which the slaughter must sever — after the slaughter, whether the greater part of them was cut; or he should see at the time of the slaughter that the greater part of them is cut; and if he did not see that the greater part of them is cut, it is forbidden. Hagah [Rema]: And they have the practice to examine in this way: that he presses the thumb upon the slope of the cap (shipui kova — the sloping part of the helmet-like cartilage at the head of the windpipe), and out of the pressure the simanim are forced outward, and then he is able to see whether the greater part of them was cut, and also whether he made one that is torn loose; for if the simanim do not go back inside after he has removed his finger, it is one that is torn loose and a tereifah (an animal with a fatal defect) (Hagahot in the Shechitot). However, there is no need to examine for one that is torn loose, for we rely upon the majority as with the rest of the tereifot; and there is one who says that he must see that they are cut in the place of slaughter without a slanting cut above the upper ring of the windpipe (hagramah). Hagah [Rema]: And one should examine for this before he throws the bird from his hand (Maharik, shoresh 38, in the name of Shechitot Ashkenazim); but if he did not examine it first, he examines afterwards, and we are not concerned that perhaps through the convulsing the cut has widened (the reasoning of the Maharik there).

Se’if 2ב׳

הַבּוֹדְקִים בְּנוֹצָה לִרְאוֹת אִם נִשְׁחַט הָרֹב, טוֹעִים הֵם.

Those who examine with a feather to see whether the greater part was cut — they are mistaken.

Se’if 3ג׳

נִשְׁחֲטָה כָּרָאוּי וּבָא זְאֵב וְנָטַל בְּנֵי מֵעֶיהָ וְהֶחֱזִירָן כְּשֶׁהֵם נְקוּבִים, כְּשֵׁרָה, וְלֹא חַיְישִׁינָן שֶׁמָּא בִּמְקוֹם נֶקֶב נִקַּב. הַגָּה: אֲבָל קֹדֶם שֶׁיַּדְעִינָן שֶׁנִּשְׁחֲטָה כָּרָאוּי, בְּחֶזְקַת אִסּוּר עוֹמֶדֶת (טוּר עַל פִּי הַגְּמָרָא) וְכָל סָפֵק שֶׁאֵרַע בִּשְׁחִיטָה, טְרֵפָה (מַהֲרִי"ל הִלְכוֹת שְׁחִיטָה וְהוּא בְּשַׁ"ס דְּחֻלִּין דַּף י' וכ"ח וּמֻסְכָּם מִכָּל הַפּוֹסְקִים בְּכַמָּה דּוּכְתֵי).

If it was slaughtered properly, and a wolf came and took the entrails and put them back pierced, it is fit, and we are not concerned that perhaps it pierced in the place of a hole. Hagah [Rema]: But before we know that it was slaughtered properly, it stands in a presumption of prohibition (Tur, according to the Gemara), and every doubt that occurred in the slaughter — it is a tereifah (Maharil, Hilchot Shechitah, and it is in the Shas of Chullin, daf 10 and 28, and it is agreed by all the poskim in several places).