One of the office cats gave birth to a litter of almost all dead kitten and refused to feed the rest. Now the last one died and she is panicking.

I'm sorry to hear about the difficult situation with your office cat and her kittens. It's understandably distressing for both you and the mother cat. There are several reasons why a cat might have a litter with deceased kittens. It could be due to underlying health issues in the mother, genetic factors, stress during pregnancy, or environmental factors like exposure to toxins.

If she's refusing to nurse, it might be because her maternal instincts haven't fully developed, or she may sense something wrong with the kittens health wise. Cats can sometimes be in shock after losing their young, which may explain her current behavior.

For now, try to ensure she feels comfortable and safe. Provide her a quiet and warm space with food and water nearby. Keep an eye on her for any signs of distress or illness like heavy breathing, not eating, vomiting, or disinterest in surroundings. These can indicate she's unwell and might need medical attention.

If you notice any of these signs or her condition doesn't improve, it's crucial to speak with a veterinarian for further advice. Consider booking a video consult with Dial A Vet to discuss her situation and explore the next steps to help her recover physically and emotionally.