The horses were starved, covered with parasites and suffering from a multitude of physical conditions.
One of the horse already had died and simply lay in a mud puddle on the grounds of a farm close to the Nicaraguan border.
The Policía de Fronteras called in the Servicio Nacional de Salud Animal to take charge and evaluate the horses.
The horses also were quarantined because officials think they were brought in illegally from Nicaragua. The animal health workers put the horses into green pastures.
The farm is in La Victoria, Upala, and police known who is the owner.