Protocols vary from surgeon to surgeon. Make sure you're clear about how Dr. L wants to deal with follow up care and specifically the frequency of soft cast changes and wound care. Sometimes the cast can slip down and then it starts rubbing somewhere that causes a sore. Or Bones might chew at the top of the cast, causing it to loosen. Might have to do an e-collar to prevent this, at least initially. Would suspect that Bones will probably be on an antibiotic like Clavamox for 3+ weeks to prevent bone infection. BTW, which leg was broken?
Edited to add: nevermind... I see that it's the right front leg. Yep, IV bag to cover that leg will protect against pee.