Rumen impaction in cattle associated with ingestion of the pupal cocoons of Gonometa spp. in Botswana

Mortality in cattle associated with ingestion of cocoons (matlhoa in Setswana) of both Gonometa postica and Gonometa rufobrunnea is rare and has only previously been reported in South Africa, Zimbabwe and Namibia. A case history of gradual weight loss, bloat, dyschezia with dry faeces and laboured gait, resulting in sudden death after drinking water and associated with ingestion of pupal cocoons of Gonometa spp., was reported by keepers at Mmaditau crush in Botswana in 2013. The crush was a shared holding in a communal area with 15 registered animal keepers. The objective of this study was to profile the history, clinical signs, post-mortem findings, morbidity and mortality from the outbreak using the descriptive study method. Altogether, 81 cattle out of a total of 507 died of impaction from August to December 2013. On autopsy, a loosely connected mass of ingesta, intertwined in ropy silky strands, was observed. It was concluded that there is no readily accessible and available form of treatment at crush level, leaving only evasive husbandry practices as the feasible option. To aid evasive husbandry management practices, temporal and spatial monitoring of population dynamics of Gonometa spp. is recommended, particularly during a drought spell when animals are prone to develop pica, as the basis for an early warning system to farmers.