Dudley Zoo has defended itself after protestors claimed animals were being "driven mad" by the conditions there.
Peter Suddock, chief executive, said it had been given a "clean bill of health" by inspectors and animal welfare "was of the highest standard".
The Captive Animals' Protection Society (Caps) picketed outside the zoo on Bank Holiday Monday.
Richard Brown, of Caps, claimed some animals' enclosures were 100 times smaller than their natural environment.
He added: "They are in concrete, they receive very little natural shade from trees, as they would in the wild.
"They're basically in such unnatural conditions where the public are roaming by in thousands by the hour and the animals are basically driven mad."
Dudley Zoo said its conditions had been approved by the Department for Environment, Food and Rural Affairs, Dudley Council and vets.