Effect of fusaric acid on brain regional neurochemistry and vomiting behavior in swine.

Fusaric (5-butylpicolinic) acid is a phytotoxin produced especially by Fusarium moniliforme, a mold commonly found in Canadian-grown corn. Experiments were conducted to determine the effects of acute doses of fusaric acid on brain neurochemistry and behavior in swine. A total of 40 crossbred barrows (initial weight 10 kg) were orally dosed with 0 or 200 mg of fusaric acid/kg of BW and five animals from each treatment were killed 4.5, 9, 18, or 36 h after dosing. All brains were dissected, and concentrations of indoleamine and catecholamine neurotransmitters and metabolites were determined. Animals in the group killed 36 h after dosing were observed for behavioral changes. Vomiting was noted in 60% of the pigs dosed with fusaric acid. These pigs also seemed more lethargic than controls and appeared sedated. The major neurochemical changes due to exposure to fusaric acid were seen in the hypothalamus 18 h after dosing. Brain tryptophan, serotonin, and 5-hydroxyindoleacetic acid all tended to be elevated by the action of fusaric acid. Brain catecholamine concentrations were largely refractory to treatment. It was concluded that exposure to acute doses of fusaric acid can cause vomiting and neurochemical changes in swine. Fusaric acid may, therefore, be acting synergistically with trichothecene mycotoxins to cause vomiting and feed refusal in pigs consuming trichothecene-contaminated feedstuffs.