My cat stopped eating on day 7 after birth, temperature 39.3, no milk letdown, stool normal, what is wrong?

A mother cat not eating or drinking with a rising temperature after birth may have lowered immunity or inflammation from incompletely expelled lochia. After birth her resistance drops and pathogens invade, causing fever.

Also, a placenta not expelled in time can stay in the womb and cause uterine infection. Take her for blood inflammation and B ultrasound to check for residual tissue, and actively treat fever, nutrition, and fluids; severe cases need drips and drugs like antibiotics, painkillers, or nutrients.