Hi Kathy,

Cellulitis can return again as it seems to have some effect on the circulatory system but it's usually a sudden onset, causes acute swelling and possibly lameness along with the swelling and is then resolved.  What you're describing is something that you probably want to discuss with your vet as it could be arthritis, hock issues, or something with a suspensory or tendon or any other part or her leg that's causing the issue. 
--
Sherry and Scutch (and Scarlet over the bridge)
EC Primary Response 
PA 2014
https://ecir.groups.io/g/CaseHistory/files/Sherry%20and%20Scutch_Scarlet 
https://ecir.groups.io/g/CaseHistory/album?id=78891