The African wild dog Lycaon pictus has declined dramatically over the past 30 years. Formerly distributed throughout sub-Saharan Africa, today c. 5000 wild dogs remain in total, mostly in southern and eastern Africa. Wild dogs' decline reflects the expansion of human populations and the associated fragmentation of habitat available to wildlife. Because wild dogs live at very low densities, even ‘fragments’ covering thousands of square kilometres may not support viable populations. Furthermore, packs often range beyond the borders of reserves, so even nominally protected populations are often subject to persecution, road accidents, snaring and disease contracted from domestic dogs. Such edge effects mean that reserves smaller than c. 10,000 sq km will provide only incomplete protection. The highest priority for wild dog conservation, therefore, is to maintain and promote the contiguity of areas available to wildlife. Establishing cross-border parks and buffer zones, and encouraging game ranching on reserve borders, will all be beneficial. In smaller areas, protecting wild dogs requires that edge effects be mitigated by: (i) working with local farmers to limit persecution; (ii) controlling snaring; (iii) routing roads carrying high-speed traffic away from wildlife areas; and (iv) minimizing contact between wildlife and domestic dogs. Most of these measures will also benefit other wildlife.