In order to work in a shelter in Germany, you must be a licensed "Tier Pfleger"(animal caretaker). One of schools is at The University of Veterinary Medicine in Vienna.

The 3 year coarse is very rigorous. Students must experience hands on work with all types of animals,from zoo animals to pets to horses and cows, pigs and laboratory animals. They study in university clinics, vets' offices, shelters and zoos.
They are also expected to study
animal husbandry
animal behavior
physiology
zoology
anatomy
Animal first aid and illnesses
animal law
physics and mathematics
With their diploma they can then seek work in zoos, shelters, vet clinics, stables or labs.