Veterinarians can often go an entire career without seeing some types of cases.
They are described in textbooks and do occur, but mostly, we hope, in our colleges or in other practice areas.
Some such cases are very unusual, some are bizarre and some are just plain difficult to deal with. Hydrops of the fetal membranes of the horse is one such case. Hydrops is more commonly seen in cattle and, while it does occur in horses, many lucky practitioners can have busy careers without ever encountering this problem.