Hybrid Hamsters Overview
Although Campbells and Winter Whites are different genetically they can interbreed; resulting offspring are predominately infertile.
Hybrids are often produced due to the mislabelling of hamsters - predominately due to pet shops. This leads to a rise in the main health problems the species have, such as diabetes in the Winter White Hamsters and glaucoma in the Campbells Russian Dwarf Hamster. It can also cause problems for the mother due to the size of the hybrid pups.
Hybrid hamsters are very hard to distinguish, although some signs include a more triangular head-shape, smaller eyes, pointed ears and a shorter distance between the eyes.
Unfortunately, these hybrids pose a real threat to the pure strains of each hamster type since they are both extremely hard to identify and the rare hybrids that are fertile would then go on to have infertile litters. Once a line has a hybrid in, it cannot revert to pure again so if this became widespread, it could lead to the end of these species in the pet trade since the remaining hybrids would have too low a fertility rate.