The court rejected pleas for quick consideration of cases involving the outcome in five states won by Joe Biden: Arizona, Georgia, Michigan, Pennsylvania and Wisconsin.
“She was struggling and I knew she needed help to get off the ice," Gil Lencour said after sliding the animal to safety.
The president failed to overturn his loss to Democrat Joe Biden in the battleground state.
Justice Jill Karofsky slammed Trump's case over its attempt to fuel doubt about a legitimate election without a single case of fraud.
The president is expected to quickly appeal the ruling, even though his chances of success there appear to be long.
U.S. District Judge Brett Ludwig said siding with the president would be “the most remarkable ruling in the history of this court or the federal judiciary.”
The state's Supreme Court sent the case to the lower courts without deciding on the merits of Trump's claims.
It's the latest setback in a string of losses for Trump's post-election legal challenges.
"He is simply trying to seize Wisconsin’s electoral votes, even though he lost the statewide election," attorneys say.
Similar Trump campaign lawsuits have failed in other battleground states.