hello guys,, i need advice , i have a dog shih tzu, two yrs. old female... shes fine until one afternoon i saw her walking then suddenly she just fall down into her feet, then she cant step her right lower leg... then i massage it but after that shes like dont want to eat,, and shes not that cheerful dog like she used to.. shes always sleeping... what will i do? im really worried for my dog... pls reply... pls.. all dog lovers out there like me!! pls.