Hore (37), of Patearoa, was convicted in the Alexandra District Court on Thursday of supplying a firearm to an unlicensed person in Paerau on May 2.
He was fined $400 and court costs of $130.
An appeal was immediately lodged and was heard by Justice Rachel Dunningham in the High Court at Dunedin yesterday.
Hore and his counsel, David Robinson, had been hoping to obtain a discharge without conviction to allow the former All Black and Highlander to attend the Rugby World Cup in the UK, where he had work available.
Hore and his wife, who is British, also planned to have their children christened during the overseas trip.
Justice Dunningham reserved her decision on the appeal yesterday and it was released this afternoon.
Hore had previously been granted diversion following an incident in 2005 in which he and two other men shot at and killed a protected fur seal on the Otago coast.
Hore was convicted and fined $2500 but the firearms charge was withdrawn, and Hore received diversion after paying $500 to charity, forfeiting the firearm and voluntarily surrendering his firearms licence for two years.
Mr Robinson did not rule out taking the matter higher following the decision.
"We need to review the decision and have a think about it,'' he said.
Mr Robinson made no comment on the decision to dismiss the appeal.
