Munchkin cats are not genetically modified in the conventional meaning of the term. A genetically modified organism (GMO) is an animal, plant, or microbe whose DNA has been altered using genetic engineering techniques. This does not apply to Munchkin cats. The shortened legs of the Munchkin cat are due to a naturally occurring genetic mutation. Humans didn’t intervene in the initial mutation. But humans have picked up on this mutation and selectively bred cats to ensure that they carry the mutation and therefore are dwarf cats.
THERE ARE SOME MORE PAGES ON DWARF CATS AT THE BASE OF THE PAGE.
Dwarf cats have standard-sized bodies with short legs. They display the symptoms of osteochondrodysplasia. It is a disorder which affects the development of bone (“osteo”) and cartilage (“chondro”).
The Munchkin Cat is the foundation dwarf cat which has spawned, through hybridization, 13 other dwarf cat breeds. People are attracted by their cute appearance. However, the selective breeding of dwarf cats is hotly debated because of the health implications. They can suffer from two health conditions: lordosis and pectus excavatum. The former is an inward curvature of the spine and the latter is a congenital deformity of the chest cavity in which it is narrower from the top to bottom and the sternum is displaced upwards.
“They can have spinal malformations, lordosis and scoliosis…and they can be born with rib abnormalities” – Dr. Carol Margolis, a veterinarian and lecturer at the University of Pennsylvania School of Veterinary Medicine.
The concept of genetic modification is normally applied to genetically modified foods which are also controversial. They are also referred to as genetically engineered foods. Genetic engineering is carried out in various ways. Genes are inserted, modified or deleted. The whole process is artificial as a result of human intervention.
There was no human intervention in the spontaneous genetic mutation of the gene which resulted in dwarfism in the first dwarf cat.
Robinson’s Genetics for Cat Breeders and Veterinarians (Fourth Edition) refers to achrondoplastic dwarfism as a ‘cosmetic’ defect (downplaying it). It appears to have been first discovered in cats in 1931 by Schwangart and Grau. Following that first discovery, short-legged cats were then found, over time, in various parts of the world. They functioned as well as long-legs cats and lived in the wild, say the authors. I’d dispute that assessment. The shortened legs of the dwarf cats must impact their athleticism. They lack the long levers of normal cats which makes them so athletic. That said dwarf cats are still capable climbers and runners.
As mentioned, dwarf cats were selectively bred by breeders. Dwarfism affects long bones more than short bones. The skull, pelvis and spine are apparently not affected (but see below: Grumpy Cat). The authors of this book say that lordosis and pectus can also occur in the general cat population (but less so?).
They say that the gene causing dwarfism appears to be an autosomal dominant gene. If dwarf cat is bred to dwarf cat, as I understand it, the kittens are unviable. The gene appears to be a homozygous lethal gene.
Grumpy Cat was a dwarf cat. She was not artificially bred. The mutation just happened. Her facial appearance appears to have been due to the dwarfism which goes against what the authors of Robinson’s say mentioned above.
SOME MORE ON THE DWARF CATS:
