Disease is a mechanic present in a few stages of Spore.
Stages[]
Creature Stage[]
Though diseases are not present as such, if a herbivore eats meat or if a carnivore eats fruit it will vomit shortly after swallowing. However, it has no further effect on the creature and it will not replenish the hunger bar. Also, if the hunger bar gets too low the health bar will decrease until the creature dies of starvation.
Space Stage[]
Diseases appear in the Space Stage. They spread through out the ecosystems and it is the player's job to destroy or remove the diseased individuals. If this is not done, the whole ecosystem can collapse. Diseased creatures are marked by a glowing yellow trail. Sometimes diseases are called biodisasters.
Galactic Adventures[]
Non-sapient creatures occassionally vomit, although this has no effect on their health.
Other[]
Diseases make no appearances in the Cell Stage, Tribal Stage, or the Civilization Stage.