My female Beagle, Mattie, injured her back. The vet tried Rimadyl with no response whatsoever. He had just gotten a new laser treatment machine. I signed her up for a 4 week therapy every other day. It only took a week and a half until I saw results. The vet let me 'bank' the last 2 weeks in case she relapsed. That was over a year ago and she has had no occurrences of back pain since.