She does, however, display stereotypical canine symptoms of rabies. Donna doesn't really know how rabies works, medically, but she has a common knowledge understanding of it combined with the hellish example Cujo set. After the horrific experience she just went through, she loses it from stress and trauma and temporarily embodies what her subconcious thinks is happening. For a little while there, she believed her rage was coming from a rabies infection, and her mind made it real.
The paramedic she bit went through the rabies treatment course because you don't fuck around with rabies and he did get bitten by someone who might have been rabid, but the treatment Donna got was in fact the normal rabies immune globulin and vaccination course, along with treating her wounds.
