The Michigan appeals court says adults testifying in court can't be accompanied by a support animal.
The court broke new ground in an opinion released Friday.
It threw out the criminal sexual conduct conviction of a Lansing-area man, saying the presence of a dog and his handler spoiled the trial.
In a 2-1 decision, the court says allowing a "fully abled adult" to have a dog "unlocks a door that we have great hesitation about opening."
A support dog named Preston was present when the alleged victim testified against Dakota Shorter in Ingham County court. The prosecutor said Preston would help the woman control her emotions.
But the appeals court says a jury should evaluate an adult's emotional state without outside support. Michigan courts have allowed child witnesses to have dogs in court.