Roquefortine in the stomach contents of dogs suspected of strychnine poisoning in Alberta.

From April to September 1990, submissions in Alberta veterinary diagnostic laboratories for which strychnine analysis was requested were tested retrospectively for roquefortine, a diketopiperazine alkaloidal tremorgenic mycotoxin. Roquefortine was found only in strychnine-negative samples. The specific origins of the fungal-contaminated specimens could not be determined. Of the six roquefortine-positive cases, four dogs that vomited prior to treatment recovered. Two dogs which died had significant amounts of stomach contents present at the time of postmortem.At the present time only one veterinary laboratory in Canada is routinely testing for roquefortine when samples are negative for strychnine. It appears that a low diagnostic rate for this type of poisoning may be occurring due to incomplete testing. The inability to differentiate between roquefortine and strychnine poisoning on a clinical basis in five of our six cases emphasizes that an accurate causative diagnosis requires laboratory examination.Research in rats and sheep has shown that the tremorgenic mycotoxins penitrem A and roquefortine are excreted through bile. Although further research is required, the submission of bile and intestinal contents is recommended if stomach contents or vomitus are not available for laboratory testing. Both of these mycotoxins should be tested for when strychnine analysis is negative as fungi may produce both toxins at the same time. In this study we were unsure if roquefortine alone or in combination with other toxins was responsible for our findings.