Abstract
The aim of the environmental enrichment is to increase the captive animal welfare, by providing them with stimulus that motivate the fulfilment in the specie natural behaviour. An environmental enrichment program was tested on the jaguar´s (Panthera onca) and cougar´s (Puma concolor) population at the Zoológico Jaime Duque, the objective was to confirm if the welfare really increased, Faecal cortisol was monitored by ELISA test, for this, validating the technique for each specie was needed. The carried out test turned out to be valid for both species; however, the cortisol levels are influenced by many multiples variables, and it was not evident the reduction of the levels with environmental enrichment.