Just a note as I've seen the point brought up several times here as well as before: wildcaught animals used to bring in new bloodlines and enhance genetic diversity are NOT inherently required to maintain perfectly viable captive populations.
Genetic diversity is determined primarily by the diversity in the initial population and the "effective population" size over time. The population size is simply the number of individuals present (in captivity, in this case). The effective population is a calculated parameter related to the number of individuals that actually contribute to the next generation. For example, we might have 10,000 Panther chameleons in captivity in the US (wild guess based on almost nothing). However, if all of these animals are the offspring of 100 male:female pairs, the effective population size is much smaller than 10,000. If all these animals are the offspring of 100 females and 10 males we have a much smaller effective population size still.
The smaller the effective population size over time the lower the genetic diversity will become. Genetic bottlenecks, where the effective population size is reduced to a small number at some point (say dozens to a few thousand individuals) have an especially severe effect on genetic diversity.
In general, we don't need high genetic diversity in captive animals in order to have healthy animals, we simply need enough diversity to keep deleterious, recessive alleles relatively rare. For instance, it doesn't matter much to us if our captive population has low capacity to adapt to increased water stress--we can just water them at the issue becomes moot. We can also preferentially avoid inbreeding and prevent less vigorous individuals from reproducing.
Adding unrelated, WC animals to a breeding program can immediately increase genetic diversity, but captive populations can reproduce successfully for a long time without it. An effective population size as small as a few dozens or better yet a few hundred individuals could, if managed in a sensible way (i.e., preferentially avoiding inbreeding, breeding the most robust individuals), provide for a viable captive population for hundreds and perhaps thousands of years.
I'm all for increasing genetic diversity with WC animals where feasible, but the idea that captive populations would inherently collapse in a few generations without them is simply wrong.
cj