His lawyers, David S. Martin and Steven W. Levine of the public defender’s office, have raised a series of objections that they say seems likely to land the case in New York’s highest court. They argue that as a therapy dog, Rosie responds to people under stress by comforting them, whether the stress comes from confronting a guilty defendant or lying under oath.

But they say jurors are likely to conclude that the dog is helping victims expose the truth. “Every time she stroked the dog,” Mr. Martin said in an interview, “it sent an unconscious message to the jury that she was under stress because she was telling the truth.”

“There was no way for me to cross-examine the dog,” Mr. Martin added.

In written arguments, the defense lawyers claimed it was “prosecutorial misconduct” for the Dutchess County assistant district attorney handling the rape case, Kristine Hawlk, to arrange for Rosie to be taken into the courtroom. Cute as the dog was, the defense said, Rosie’s presence “infected the trial with such unfairness” that it constituted a violation of their client’s constitutional rights.

Ms. Hawlk declined to discuss Rosie. In written arguments, she said that all Rosie did was help a victim suffering from serious emotional distress, and she called the defense claims “frivolous accusations.”

The defense lawyers acknowledged the risk of appearing antidog. Rosie, they wrote, “is a lovely creature and by all standards a ‘good dog,’ ” and, they added, the defendant “wishes her only the best.”

As the lawyers prepare their appeal, Rosie has been busy. She spent much of her time in recent weeks with two girls, ages 5 and 11, who were getting ready to testify against the man accused of murder in the stabbing of their mother.

The Dutchess prosecutor in that case, Matthew A. Weishaupt, argued that Rosie and dogs like her did not affect the substance of the testimony about horrifying crimes. “These dogs ease the stress and ease the trauma so a child can take the stand,” Mr. Weishaupt said in an interview.