Took PD back to the vet on Thursday with an empty stomach for her x-rays. The 3 x-rays came back "Negative" with nothing broken or out of place. The vet seems to think after the exam that she has a possible torn ligament on the knee joint. Even after sedation, PD let out a yelp when the vet moved the joint to see if it was the ligament. The vet put her on pain meds and meds for arthritis relief. Got her back home and we will see how she does for a couple more weeks. If no improvement, possible surgery to fix the ligament.
For now, rest, meds and no running for PD...