Is the slaughtering of a dove with a dull knife, severing it in three cuts, followed by some bleeding from it, and it did not move after the slaughter, and a somewhat large amount of blood was found inside it, considered a valid slaughter according to Islamic law? And is there torment for the animal in that, and what is the expiation for it?

For an animal to be lawful (halal) to consume, it is a condition that the two jugular veins (wadajayn) along with the windpipe (hulqum) or the gullet (maree') are severed, or one of the two jugular veins along with the windpipe and the gullet. The slaughtered animal is valid if three out of the four (mentioned parts) are severed. It is disliked (makrooh) to slaughter with a blunt instrument, as this causes suffering to the animal, and the blade must be sharpened before slaughtering.