Why does my hamster have scabs and swollen feet? What should I do?

Thank you for using Petco Pet Education Center, formerly Petcoach! From the photo, I can see a small ulceration or reddened area on one of Leilani's feet. This can be due to a pressure sore and a secondary infection. These issues can be caused by inappropriate flooring in the cage such as wire. Leilani should have a solid floor cage with plenty of bedding. Heavier animals are predisposed to these types of wounds from the increased pressure on the feet, so Leilani may need to cut down on treats if she is overweight to help the condition resolve. You should have Leilani seen by a vet as soon as possible, as she may require antibiotics if an infection is present. In the meantime, you should keep the area clean and apply a small amount of SSD (silver sulfadiazene) ointment to the area to promote healing. I hope this helps!