INTRODUCTION

On most occasions, in litters of dwarf rabbits, rabbits are born with certain genetic anomalies which are usually shown from the moment of birth.  These abnormalities are mostly the result of the dwarfism gene. 

The ‘Max Factor’ is limited to a few specific breeds (it is not present in all breeds of rabbits or in all breeds carrying the dwarfism gene).

WHAT IS ‘MAX FACTOR’?

Roger Roth wrote the first article on Max Factor, published in the July 1996 issue of Dwarf Digest. He and others have spent much of their time documenting the existence of the Max Factor gene. In the 1980s, a group of breeders went through the entire process of documenting animals carrying the gene and followed the normal mendal ratio procedure and proved the existence of the gene. The name ‘Max Factor’ was given to this gene after finding that an imported Netherland Dwarf male named Max appeared to be the original carrier.

Max Factor acts as a normal recessive gene. This means that both parents MUST carry the gene for it to be expressed (manifested in the litter). These Max Factor puppies are sometimes called ‘frogs’; this type of malformation only occurs in the Netherland Dwarf and in breeds that have used the Netherland Dwarf breed for their creation.

CHARACTERISTICS OF ‘MAX FACTOR

Max Factor is a recessive gene different from the gene for pituitary (peanut) dwarfism in rabbits. After many years of documenting the reaction of both genes, they are different genes with different expression in pups. The double dwarfism gene gives us what many call peanuts with poorly formed hindquarters, large head and small size. The ‘Max Factor’ will usually give you dogs born with open eyes (infected from the birth canal) and some kind of deformity in the feet; often the front feet will simply be ‘flippers’ without toes and sometimes you will get one with extra toes. The hind feet are usually ‘upside down’ or turned in. 

[Top left: ‘Max Factor’ (dead) gazapo with frog feet || Top centre: ‘Max Factor’ (dead) gazapo with open eyes || Top right: Healthy, well-fed two-day-old gazapo].

CAN A ‘MAX FACTOR’ RABBIT BE SAVED?

It is quite difficult for a ‘Max Factor’ toad to survive, as a general rule they are born dead or die within the first two days. If they survive and reach adulthood they will be blind animals very prone to eye infections and with joint problems as a result of having deformed legs.

CAN I RE-CROSS A PAIR OF RABBITS THAT HAVE PRODUCED ‘MAX FACTOR’?

There is no reason not to mate them, except when more than 25% of the litter are ‘Max Factor’ affected animals. 

With a normal genetic expectation, you can expect 25% to not carry the gene, 50% to be carriers and not show it and 25% to be ‘Max Factor’ animals. Most of the animals from the best breeders are ‘Max Factor’ carriers. At first, it was difficult to get breeders to talk because they thought they had something wrong with their gene pool.

It is estimated that at least 80% of Netherland Dwarf winners at national shows carry the Max Factor gene.

CONCLUSION

The ‘Max Factor’ can be shocking to any breeder (whether novice or experienced) or rabbit enthusiast as it is impressive to see a newborn doe with its eyes open, especially when it has survived parturition.  These are animals that normally have no life expectancy whatsoever and, if they do, it is best to be respectful of them and put them down as humanely as possible to avoid future suffering. If they do not want to do this, it is the owner's responsibility to give them the best possible life until they die naturally (sooner or later).