I’ve unfortunately had to use critical care before. Follow the instructions for mixing and I only made small batches at a time. I didn’t add calcium or anything else to it. I would only give it after making attempts to offer regular feeders. The hard part is getting their mouth open. Veileds, with their sass will gape and we can take advantage of that and the built in handle of their casque, but panthers are tough. I had the best success with using a guitar pick to gently open the mouth enough to get the tip of the syringe in. Aim for the back of the throat as the airway is in the front. I usually gave extra water too while I was there…about 0.5ml.
I am a bit surprised about the choice of medication. Usually metacam is given for inflammation pain and I forget which gout med is prescribed (allopurinol or colchicine), but without a med to reduce the uric acid, the gout will remain. Usually it’s a lifetime treatment to prevent recurrence, at least for humans. The Tramadol is a pretty potent pain med, so at least he should be more comfortable.