Outbreak of salt poisoning in goats in the state of Pará, Brazil

Resumen

The present study reports two outbreaks of salt poisoning in goats on a property in the state of Pará, Brazil. The outbreaks occurred in July and August 2011 when young and adult goats received a mineral mixture after approximately three days of restriction from the supplement. The animals were kept in barns with a high stocking density and had an inadequate supply of water. In the second outbreak, the goats were supplemented too with brewery residue added to 3.3% of the mixture mineral. From a flock of 191 goats, 12 animals (nine crossbreeds, two Anglo-Nubians and one Boer) showed nervous symptomatology, and the morbidity rate was 6.28%. The most frequent clinical signs were head lowering, head tilt, muscle weakness, mydriasis and ataxia. Three goats died, four recovered spontaneously from the first outbreak, and five recovered from the second outbreak over three days after treatment with dexamethasone, thiamine and gradual water supply. The lethality rate was 25%. In two animals, necropsy was performed, and no macro- or microscopic alterations in the nervous system or other organs were observed. These negative pathological findings indicate that the neurological clinical signs were initiated by functional disturbances in the central nervous system. In the brain, a high sodium concentration (3703 and 3675 ppm), compared with the reference values for cattle was detected. Normonatremia was observed in the sick goats, and hypernatremia was observed in the goats from the same lot of affected animals based on blood serum samples obtained before the first outbreak. These results pointed out that the goats were consuming high sodium concentrations. Normal values for the sick animals were assigned after rapid osmotic control via adequate water intake. We conclude that the salt poisoning on the goats occurred due to a high intake of the mineral mixture caused by management errors and associated with water restrictions.