Why is my 2-month-old kitten lethargic and not eating after moving?

It is concerning that Luna has had a change in behavior and has lost weight. While it can take time for a cat to adjust to a new member of a household, it's an extreme reaction to lose weight. I would be concerned that she may have an medical illness causing her change in behavior. Lethargy and anorexia are unfortunately very general signs of illness and can be caused by systemic illness, infection, inflammation, or injury. I'd recommend a visit to the vet this weekend. The vet can diagnose if there is medical cause behind these symptoms, and can discuss treatment with you if there is one. Good luck, I hope this helps!

Luna looks fine from the photos. I suggest you get a small scale and weigh her twice a week. As long as she is gaining weight I would not be worried about how much she is eating. It is not likely that a kitten would starve herself. At 2 months old she should be ready for her first vaccines. If you have not done that already, you should get her to your vet for her vaccines and an exam. That way your vet can check her over thoroughly (including her mouth) to see if there is anything to be concerned about. I cannot really tell much from a couple photos other than the fact that is adorable! Hope this helps. Best wishes.

Kittens can sleep a lot, but if she is very listless I would be worried that she is ill and should be seen by a veterinarian right away. Starvation and dehydration can very quickly cause a kitten to go downhill which could be why she is so lethargic and requires medical care. She may also be younger than you suspect and still need additional care. Your vet can also help determine her age, and you can use this guide if she is young for rearing orphaned kittens: https://www.petcoach.co/article/how-to-raise-orphan-kittens/

I am concerning that Luna isn't eating or drinking, and while you can see a decrease in appetite and activity after vaccines, it isn't normal to stop both eating and drinking completely. First I would try to tempt her to eat with some boiled white meat chicken (no bones) in some low sodium gently warmed chicken broth or tuna in spring water. You can also offer her small amounts of Pedialyte. If she refuses to eat or drink those things, then yes I would take her into an emergency vet right away.

Luna may be feeling a bit stressed out if there are a lot of other people or pets in the house and may be staying near her kittens for protection and safety. Giving her some space to relax and care for the kittens as well as keeping curious children and pets away from them can help. You can also try placing her food and water near the area she is hiding so she has the ability to get the food and water she needs while nursing her kittens. You do want to make sure all the kittens are doing OK by checking on them every so often, however too much can increase stress on mom and babies. If Luna doesn't improve or you see any signs of illness from mom or babies, scheduling a vet check is best.

Poor Willow! It does sound like she isn't feeling well. It would be best to bring her to a vet ASAP to check for issues such as a foreign body from eating any kitty litter, GI upset, illnesses, etc that could be causing the symptoms you are seeing, especially if this has been ongoing for more than a day.

It sounds like he is getting sick. Without additional clinical signs it is hard to say exactly what is causing his lethargy and decreased appetite but he could be starting with a respiratory virus or a gastrointestinal virus. He could also have parasites that need to be treated. If it continues than he should be examined by a vet to determine the cause. Your vet can run lab work to help diagnose and then determine the best way to treat. If he is unvaccinated, please discuss a vaccine plan with your vet once he has recovered from this illness.