Only one bonded dragon remains in Westeros: Morning, the pink-and-black dragon bonded to Princess Rhaena of House Targaryen.
The Dance of the Dragons was as devastating to dragonkind as it was to House Targaryen itself. At the war's outset, nearly twenty dragons lived — some wild, some bonded, some ancient beyond reckoning. By its end, most were dead. Vhagar, the greatest dragon in the world, fell above the Gods Eye when Aemond Targaryen flew her against his uncle Daemon, rider of Caraxes, in single combat. Neither dragon survived, and neither did their riders. Meleys, Syrax, Sunfyre, and Tessarion all perished in the fighting. Even the wild dragons of Dragonstone, Seasmoke, Grey Ghost, and others, were drawn into the conflict and did not survive it. The war did not merely wound the dragons. It nearly ended them.
After the war, the only other surviving bonded dragon, Sheepstealer, took flight with its rider Nettles and never returned. The wild dragons Silverwing and the Cannibal soon disappeared as well and have not been seen since.
Eggs are plentiful on Dragonstone, but the few that have hatched have produced small, deformed hatchlings — wingless, or with twisted limbs, or with scales that sloughed away within days of hatching. Some were born too weak to feed. Others simply stopped breathing without apparent cause. None survived long, and even those that had likely would never have been capable of flight or carrying a rider.
Some believe the dragons, like so much else in Westeros, lost the magic that sustained them, for after the Dance, it seemed as though magic had fled the realm entirely. Others point to the dragonlords themselves: that the Targaryens, in their madness and ambition, burned away the last of the ancient bond between rider and dragon, and that without it, dragons cannot truly thrive. A few maesters have suggested a simpler explanation — that centuries of controlled breeding on Dragonstone had already weakened the line, and the Dance was merely the final blow. Whatever the cause, the result is the same. The age of dragons, it seems, is ending. Perhaps it has already ended, and only Morning remains to mark its passing.