OWNERS and trainers have expressed concern over the high amount of winners’ samples showing up positive since the Trinidad and Tobago Racing Authority (TTRA) switched to an American laboratory to carry out dope testing.

Over the past four months, since post-race urine samples are being sent to IOWA State University, USA, four winners have been tested for illegal substance -- three for use of therapeutic medication and one for a performance-enhancing substance.

Some trainers want to know what the American laboratory is considering to be a “positive” test.

When urine samples were sent to a Canadian laboratory, chemists there worked within guidelines from the Ministry of Agriculture as to the level of therapeutic drugs that can be considered to be a positive test, one former racing official said.

But trainers are arguing that they are unaware of the limit of detection used by the American testing laboratory.

The concerned trainers say one of the reasons why they are calling for threshold levels with respect to equine medication, is because they would have an idea if a horse was tampered with before race or whether the medication was in the horse system longer than the prescribed period given by a veterinarian.

They claim that since their livelihood is at stake now (facing a ban) with new ultra-sensitive testing procedures, they would like some kind of guideline from the US laboratory as to the traces of medication found in the sample.

Trainers are arguing that minute traces of therapeutic medication do not enhance the performance of a horse.

The TTRA has adopted a zero-tolerance policy regarding therapeutic drugs, which trainers want reviewed.

They claim that most of the horses in training suffer with various types of injuries and require this type of equine medication.

In the case of Millionaire, which was tested a week ago for a performance-enhancing drug, the owner and trainer claim the horse was tampered with.

There is a strong feeling that some big gambler became a millionaire after the horse won over 1,750 metres for the first time last month.

A Guyanese turfite is suspected of giving a groom the drug to administer to the horse. The horse, which opened in the betting at 14-1, drifted out to 2-1, much to the surprise of the owner and trainer.

A trainer, who has a small string of horses is now facing a ban.