The Houston toad (Anaxyrus houstonensis) was one of the first amphibians to be protected by the Endangered Species Act in 1973 and is found only in east-central Texas. Habitat destruction, droughts, and a devastating wildfire have placed additional pressure on declining populations. The Houston Zoo has been working with local partners since 2007 to develop a captive assurance colony of Houston toads and to produce progeny for release back into the wild. Our captive assurance colony is truly the thin green line between species persistence and extinction. Medium-sized toads that vary in natural hues from green to red to brown, these amphibian ambassadors are the little toads that could. At least, we hope they are. Our colony housed between 400 and 2,000 toads that have survived a variety of medical crises, including developmental abnormalities, mycobacterial infections, encephalitis from chlamydial infections, and tumor development. We have learned a lot about amphibian medicine and had both missteps and triumphs along the way, building up toad numbers one season at a time and releasing individuals to the wild in an effort to reduce the chance of extinction of this native Texan.