However, Niko Souto, 41, who runs a yard in the village of Amil, said his family does not make a profit. The proceeds help pay for fencing to stop the horses wandering onto roads or farmlands.

Costs, including vet fees, insurance, fencing, microchipping and GPS equipment for tracking, are multiplying too, Souto said.

Carlos Souto, Niko's father, said the horses were descending from the hills more frequently in search of pastures as Eucalyptus plantations spread — meaning they needed more minding.