INTRODUCTION

Many times we have come across bunnies in shops, groups and family catteries with the most curious spotted patterns, striking blue eyes, heterochromia or something as subtle as depigmented nails in specimens that should not have them. 

Those owners who have no knowledge of rabbits or who have not studied them in depth believe that their rabbits are sick because half of their eyes are one colour (blaming it on cataracts or e.cuni), they believe that they are "special" because of this or simply do not give it any importance, but it all has one origin: the vienna gene. 

THE VIENNA GENE

The vienna gene (Vv) is the gene that produces white rabbits with blue eyes when one copy is inherited from each parent, becoming dominant (VV). This gene is not dangerous at all, even when taken in duplicate (which is not the case with the dwarfism gene) and can manifest itself in many different ways. 

For a rabbit to be a vienna gene it only has to take one copy from both parents, whereas to be a BEW (Blue Eyed White) it has to take two copies, it is a recessive gene that can remain for several generations in the same bloodline and is very popular with pet breeders. 

This gene is banned in the great majority of breeds, being accepted only in some associations that reward morphology before colour, or in some shows that have a section of "non-recognised breeds or varieties"; some of these associations that recognise it or have recognised it are AECCE, ASNAC and CECR. Some virtual groups of ARBA (USA) admit it in virtual shows as "non-recognised breed or variety" (by ARBA). 

HOW DOES THE VIENNA GENE MANIFEST ITSELF?

The Vienna gene as we have said is very capricious and can manifest itself openly ("Vienna Marked" or "VM") or remain hidden and manifest itself in the next generation ("Vienna Carrier" or "VC"). Vienna Marked" can manifest itself in many ways:

• White spots or spotted colour patterns on colours that should not have them.
• Blue eyes in "non-white" specimens.
• Heterochromia (one eye completely of one colour and the other blue).
• Split eyes (one iris is of two colours).
• White nails on patterns that should not have them.
• Excessive white hairs on coloured specimens.

VC (Vienna Carrier) rabbits do not have any of these characteristics, so they can introduce the gene into a bloodline from their offspring, which can be detrimental if the breeder is not dedicated to BEW or VM. 

THE VIENNA GENE IN SELECTIVE BREEDING

As we have mentioned, the vienna gene is not allowed for show in the great majority of breeds, so if the breeder is not dedicated to BEW rabbits nor has a line focused on this colour, the unknowing introduction of a vienna rabbit (Vienna Carrier) in his kennel can destroy the work of years, make him lose money and, if he has to dedicate himself to clean this blood line of vienna, he will have to invest many years to achieve it. This shows how important pedigree and honesty are when sending an animal to a partner's home (in our country or abroad), as this world of fancy rabbit breeding is very small and everything ends up being known. 

CONCLUSION

VM rabbits are beautiful and we can find in them very striking patterns such as the "Whitehead", the "Witkop" and the "OB" (white ears), but when we talk about selective breeding for exhibition it is a double-edged sword. 

All rabbits are very beautiful, unique and special but you have to admit that the vienna gene has something different that always catches the eye.