Koi fish badly need attention

I love Loro Parc. It's my 3rd visit. The cages always seem clean and on the whole the animals look well cared for. However I was deeply upset to see how many of the Koi were sickly looking. Many with ulcers or bacterial infections. These really needed to be removed to a quarantine area and either treated or in worse cases pts. I keep Koi myself so do have a good idea on how a healthy koi should look.