Test results confirmed the horse, which exhibited neurological symptoms similar to the highly contagious Equine Herpesvirus 1 (EHV-1), didn't have the virus, the University of Minnesota Extension announced Tuesday.
The test was conducted through the University of Minnesota Veterinary Diagnostic Laboratory.
The family who owned the horse decided to euthanize the animal because of its worsening condition and poor prognosis.
But because there was a possibility the horse had the deadly virus, exhibitors at the horse show were asked to quarantine horses that participated in the show and watch the animals for symptoms of the virus.
That quarantine has now been lifted.
Officials did not say what caused the horse's symptoms.