Jay is right. Extremities swollen due to lymphedema are quite suspect to infection. The skin should be inspected daily, and antibiotics started if any wounds are found. My experience with lymphedema is mostly with *** cancer patients. Gentle compression and exercise may be helpful. Perhaps if you can get the little one comfortable with being on his back, you could gently massage his legs, moving from his feet and toward his body, helping to push fluid back into general circulation. You could also possibly try applying Co-flex as a gentle wrap to his legs, helping to keep edema down. You would definately want to remove the bandages a few times a day to assess the skin.
Sometimes gentle diuresis can help, using a drug that will spare the body's electrolytes. Electrolyte sparing drugs take longer to work, but you don't have the danger of depleting precious minerals like potassium, which are needed for proper muscle and cardiac funtion.
Also, if you don't mind a little foot work, most local hospitals have a cancer center that works with a lymphedema treatment center. A therapist in such a center may have some helpful tips. If you are in a major metropolitan area, there may even be a vet center that performs physical therapy for dogs. A therapist there could probably teach you certain message and treatment techniques that may help.
Most of all, don't give up. We know that you want to do your best for your little one, because you have accessed this website. Do your best, and you will make the little one comfortable for as long as you can.
Good luck, and let us know how things go.