People who have spent a lot of time in contact with animals often develop animal-induced allergies, some of them quite serious  In a survey of current employees in major zoos, about 30 percent had animal-induced allergies
Based on this sample, experts conclude that among members of the general population who have spent a similarly large amount of time in close contact with animals, the percentage with animal-induced allergies is not 30 percent but substantially more
The percentage of the general population whose level of exposure to animals matches that of a zoo employee is quite small.