My boxer had similar issues during her final years and I was told it was totally normal for dogs around that age mine was 12. My Vet put me onto this vitamin supplement https://www.amazon.com/Canine-Cell-Nutritional-Supplement-Vitamins/dp/B01EUNO166/ref=sr_1_3?crid=MII0P08P7Q30&keywords=red+cell+for+dogs&qid=1687119019&sprefix=red+cell%2Caps%2C142&sr=8-3 . I firmly believe she gave us a couple more beautiful years due this.