I'm so sorry Minnie was injured. I googled Pet Tinic Plus & found this:
Pet-Tinic information & Pet-Tinic pricing at HealthHaven.com
Maybe the shot the Vet gave at his office was what made her sleep when you brought her home. It does sound like from review above that it has been given for injured back or legs. I would give a call to the Vet though for reassurace.
Hope Minnie is feeling much better today & that she has a speedy recovery. Hugs!