Why is my hamster skinny, not eating, has diarrhea, and is lethargic?

The wet bottom could be due to diarrhoea. These signs could be compatible with an inflammation infection of the gastrointestinal system and surrounding organs (like pancreas and liver), which is a very concerning sign in hamsters. A clinical examination at your local veterinarian is immediately essential to confirm these clinical suspicions and treat appropriately. Antibiotics are likely to be needed. Unfortunately there is nothing you can do back home, as medications are required as soon as possible. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.

I am sorry to hear that Pepper is so ill. I worry that he may likely have dental issues that are preventing him from eating. Certainly there can be other problems but dental disease is the most common. I would highly encourage you to have him evaluated by your veterinarian as soon as possible. They can not survive long without eating. Best of luck and I hope he improves soon. Thank you for using Pet Coach.

Hamsters that become extremely lethargic unfortunately rarely survive, it could be a bloat or a gastrointestinal infection, it could also be due to a tumor, it's hard to say, you need to take him to the vet urgently.

Keep the cage clean and warm. Keep him as stress free as possible. Stress plays a large role in illness or infection in hamsters. Discontinue feeding any fruits or treats until his stool is normal. If he doesn't begin to improve in a day or two, then he should be seen by your veterinarian.

Thanks for reaching out about Vasia. It would be a mild concern that she has lost 20% of his body weight. Age is not a disease, and some organ system is probably responsible for the weight loss. Renal disease is fairly common in aging hamsters. Try and monitor water consumption and urination. Good luck.

Your hamster may be suffering from ectoparasites such as mites or fleas and/or an allergy to the bites. I suggest you take him to a veterinarian for a hands-on exam and diagnosis. The vet can prescribe or treat your hamster with a proper medicine to kill the parasites. There are mite treatments for hamsters available in the pet shops, but I am not sure whether they are effective. You will definitely need to clean and disinfect your hamster's cage, bedding and toys and food and water containers to hopefully prevent the mites from reinfecting your hamster after treatment.

Those symptoms tend to happen in very sick hamsters, usually due to severe dehydration. most hamsters do not recover from turning that ill but if you want to give her a chance to survive you will have to take her urgently to a vet in order to attempt supportive treatment.