Trainer Charles Byrnes has been unsuccessful in his appeal against the decision of the Irish Horseracing Regulatory Board's Referrals Committee to suspend his licence for six months and fine him €1,000.
Byrnes was handed the penalties after one of his horses tested positive for a prohibited substance after being pulled up at Tramore on October 18, 2018.
The urine sample of Viking Hoard was found to contain hydroxyethylpromazinehydroxide (HEPS), a metabolite of acepromazine (ACP), which is a sedative and forbidden under the rules of racing.
The IHRB committee had ruled that although it was not alleged Byrnes was directly involved in either the administration of ACP or the betting patterns surrounding the horse, "the evidence showed that Viking Hoard was subject to a dangerous degree of sedation during the race", and came to the conclusion the horse had been "nobbled" by an unidentified third party when left unaccompanied.
The IHRB added at the time that Byrnes had signalled his intention to appeal -and the Limerick trainer has been able to continue having runners in the interim - sending out Off You Go to win at the Dublin Racing Festival.
That appeal was heard last week, and a verdict supporting the original decision was published on Thursday.
In its findings the appeals body said submissions referenced "Mr Byrnes' personal and financial circumstances and his success as an experienced and capable trainer for 26 years", and that the loss of his licence "would be ruinous for him" and that his employees would have to be let go and horses currently under his charge would have to be sent elsewhere.
But it added that "the focus of the Appeals Body's deliberations must be on the blameworthiness of Mr Byrnes' conduct. In the judgement of the Appeals Body, Mr Byrnes failure to ensure any attendance on Viking Hoard at Tramore Racecourse stables for two significant periods prior to the race on October 18 was, in the language of the Referrals Body, 'seriously negligent'."
It added: "Whilst the Appeals Body accepts that there is no evidence that he (Byrnes) was aware of the extraordinary and suspicious betting activity on Viking Hoard, it simply cannot ignore the very serious consequences which flowed from his misconduct and dereliction of duty."
The appeals body said the penalties were to take effect 14 days from the publication of the verdict.
Byrnes was also ordered to pay costs, estimated at €2,000.