Such programs are long term, and involve the danger of losing the species integrity. The answer is to never let population numbers get so low that such extreme measures need to be taken, but for many species it is too late for that. I guess the answer is complicated. But they can handle it, it's the way they've been for millions of years. Cats generally have a lower heterozygosity equal to that of other animals it would mean that the males would have to wander vast territories, and offspring would have to be sired by males from either end of the continent.
Genetic variation enables a species to adapt and evolve to new circumstances.
Alleles have been developed by the process of mutation and natural selection. Most animals now aren't going anywhere, and won't have the variability required to evolve anymore. It would take a huge place to build up a big enough population to be able to maintain signif- icant evolution. The only things animals need diversity for nowadays is primarily for the epidemics that will come through, and then also for the disasters that will occur maybe three times a century. The world has changed.