Hmmm. What to use depends on the rest of the symptoms. If the dog has other geriatric complaints, then we've had good luck combining Hoxsey and SMS with Rehmannia Eight in these old guys.
If there are no symptoms to guide you, we've used Xiao Chai Hu Tang to help enable the other two formulas you're using.
Always, we'll try a very low dose (0.1 to 0.2 mg/kg) of pred SID to BID TO take lymph nodes down, given usually a week or three at a time, on an as needed basis.
As well, we routinely use oral vitamin A and D, usually just the large animal preparations that contain 500,000 IU per ml of vitamin A. We give them orally once to twice a week. I'd probably go with about 600 000 IU of A and the associated quantity of D3.
Finally, we move the dog onto a non-dampening diet (higher protein, lower carb). Home-cooked is ideal, because then we can get lots of antioxidants in there using fresh produce. We supply the owners with guidelines adapted from the 'paleolithic diet' in the Manual of Natural Veterinary Medicine (Elsevier).
Hope that is useful advice for your patient.
Steve