Hello and welcome! So sorry to hear about Holly and her problems. Although I lost my girl last year at 14+, I really don't know that much about seniors because the only problem we had to the last day was bilateral hip arthritis. However, there are people here who know a lot about senior labs and their problems. It's still a bit too early, but I guess the Forum will become a bit more active in a few hours. Sending good thoughts for Holly and keeping our fingers and paws crossed, so you find positive answers to your questions. M&M
Also, you might get some info faster if you post one more time here Senior Labrador Health as this section focuses on senior dogs and their health problems. Good luck.