What diseases did dinosaurs suffer?

A few examples of dinosaurs with bone disorders, similar to severe arthritis have been discovered (Iguanodon); this leaves a very distinctive pitting and knobbling on the surface of bones. Other examples of pitting on the frill of some ceratopian dinosaurs looks suspiciously similar to forms of bone cancer. Beyond these very obvious forms of illness, which leave traces on the surface of, or within, bones relatively little is known about dinosaur illness. Sick animals would have been picked off by predators and scavengers, so few traces of them would be expected to survive. There are examples of dinosaurs known which have clearly been injured (broken hip bones and spines on the backbone) and recovered but these are very much the exception.