Starshine

Starshine is caused by a sudden and extreme overload of magic, a condition which can only be triggered by consuming solid magic. As solid magic only exists in the form of gods, and more specifically their bodies, starshine can only be caused by consuming divine flesh (or blood).

Overflowing magic makes the afflicted dragon glow, appearing to be lit from within. Light emits from underneath their scales (or feathers, or fur), brightest on the chest (near their magical core), as the body attempts to vent the magic as safely as possible. The air around them gets distorted from the vented magic, appearing almost to waver (as it does in extreme heat), and holding a hand near lets one feel the trembling of the air as magic passes through it.   In mild cases, spontaneous magic may occur in the air around the afflicted, caused by the high amount of uncontrolled magic passing through it. As these magic occurances are unguided, they can be dangerous to the afflicted or to their environment.
In more severe cases, the magic can't be vented fast enough, and spontaneous acts of magic occur inside the afflicted's body as well. As these are still completely uncontrolled, and might take any form, they are extremely dangerous to the afflicted, and pose a reasonable danger to their environment as well.
In extremely high doses, the overspilling magic can't be vented at all. In these cases, the afflicted becomes brighter and brighter as magic builds up, until their body literally bursts apart, the pure magic releasing in one aggressive outpouring. This rush of pure magic flowing away and into the environment is considered especially dangerous, as nearby dragons may absorb some of the released magic, and become afflicted by starshine themselves, even if they haven't consumed any magical flesh.   It is said that, in the right circumstances, consuming divine matter may grant the consumer great powers, like in the myths of divine nectar. However, no (conclusive) proof of this exists.

No treatment for starshine exists. It is a short-lived condition, which will fix itself, and which will do so very rapidly.   In all cases, venting the magic will take no more than an hour, measured from when the flesh is first consumed. In mild cases, little magic has to be expelled. In very severe cases, the afflicted will die before long. Even in severe cases, which straddle the line between the two, within an hour the afflicted has either vented all magic, or died.

Starshine, by nature, is a dangerous condition. Even in the mildest cases, uncontrolled magic acts occuring near the afflicted may cause severe injury or even kill the afflicted. In more severe cases, where magic occurs inside the body, death is almost guaranteed. If not immediately, side-effects from the unknown magic will surely lead to their death sooner than later. In very extreme cases, starshine itself will kill the afflicted, and gruesomely, too.

Starshine occurs among all dragons, regardless of age, race, sex, or any other such matter. Some things may affect severity, with dragons with big magic stores being more likely to have mild cases, but ultimately it has little impact. All dragons can be afflicted with extremely severe starshine, no matter how (non-)magical they may be.   Although starshine is known as a dragon's condition, all living beings can consume a deity's flesh, and thus all living beings can become overloaded with magic. However, considering the rarity of divine flesh, no one would intentionally feed it to an animal, and it is hard imagine the circumstances in which it would occur accidentally. After all, what god would let an animal feed on them?

Starshine is largely considered a fictitious disease, as few dragons even believe that gods exist among them. It occurs very rarely, largely due the difficulty of acquiring the flesh or blood of a god. In modern times, it is mostly found among those who believe that deities exist, in physical but not mortal forms, limiting it to (religious) fringe groups and as the result of specific rituals.