I found a baby Norway rat outside today after having foundation work on our place. Very weak and dehydrated. Got him inside, rehydrated then formula given. Foot appeared fine. Was placed in car board box with heating pad and soft bedding and have been feeding every couple hours. Approximately 5 hours later paw began to change color and swell slightly. Now 7 hours later it is very swollen and purple. Sprain or broken from falling from our subfloor to the ground possibly? If so.. I didn’t think something like that could take so long to show signs. Any help is greatly appreciated. Thank you.