Hi Goldie, welcome to Tripawds. I hope you don't mind but I moved your post to this "Size and Age Matters" topic so it wouldn't get lost in the other one where you posted. This way you get a discussion all to yourself.

So if I'm understanding you, you had the chemo before amputation and the leg is still there? I' sure that's not unheard of but I can't recall a pup here having chemo before amp. Is it osteosarcoma you're dealing with? If so, what is the tumor like? Why did they suggest leaving the leg on? 

You'll find lots of senior dogs do great on three legs. Just scroll through the stories in this discussion and you'll see them. 

Lethargy and appetite loss are common when it comes to chemo. Did your vet provide information about what to expect? As you'll find out, lots of dogs' appetites wane but they do get them back. If the nausea is really bad vets usually prescribe something called Cerenia to help reduce it. 

Before you buy any new supplements or change her food, please talk to your oncologist. Changes like this during chemo are usually discouraged. That way you will know that it's the chemo causing her lack of appetite, etc., not the food or supplements. If you haven't checked out Dr. Dressler's Dog Cancer Survival Guide, I highly recommend it, he covers a full-spectrum approach that covers use of both holistic and conventional therapies as you're doing, but bases his recommendations on supplements and diet that has shown strong anecdotal evidence as being beneficial.  

I hope this helps. We're glad you found us. Please share more of your story so that we can better help you.