After speaking concerning the well being problems with brachycephalic cats, just like the Persian, and Scottish Fold cats, we’re going to speak about one other controversial breed: Munchkin cats. Munchkin cats, additionally referred to as dwarf cats, have a genetic mutation inflicting them to have quick legs. On this article, we’ll focus on what we find out about their genetic mutation, their well being, and if this breed will be thought of moral.
The historical past of the breed
Experiences of cats with quick legs have been already current in 1944. Nevertheless, the historical past of the Munchkin breed is newer. In 1983, Sandra Hockenedel discovered a pregnant feminine stray cat, Blackberry, with quick legs in Louisiana. Half of her kittens additionally had quick legs: the Munchkin breed was created by mating this feminine cat and one in all her male kittens with home cats.
The breed was then acknowledged in 1994 by The Worldwide Cat Affiliation (TICA).
So, Munchkin cats have a pure mutation that appeared spontaneously in home cats. This mutation has appeared additionally in different elements of the world and at totally different instances, as reported by Messy Beast.
These days, the Munchkin breed has been crossed with varied different breeds to create new dwarf breeds. Examples of such breeds are the Minuet/Napoleon (a Munchkin/Persian cross), the Bambino (a Sphynx/Munchkin cross), the Scottish Kilt (a Scottish Fold/Munchkin cross), the Dwelf (Bambino/American Curl cross), …
As a result of the Munchkin and these spinoff breeds are characterised by physique deformity, many main cat fancy associations–such because the Féline Worldwide Féderation (Fifé), the Governing Council of the Cat Fancy within the UK (GCCF), or the Cat Fancier Affiliation (CFA)–don’t acknowledge them. The genetic and well being points that shall be mentioned on this article additionally concern the assorted spinoff breeds.
In keeping with breeders, Munchkin cats can run and behave usually, with the exception that they will’t leap as excessive as a normal-legged cat.
a Scottish Kilt cat
The genetics
Munchkin cats have a type of disproportionate dwarfism, additionally referred to as chondrodysplasias, as their legs are quick however the remainder of their physique and their head is regular sized. This mutation prevents the bones from their limb to develop usually, therefore their decreased measurement.
The gene of this mutation has lately been recognized in 2020 and has been confirmed to be a dominant gene. As well as, as a result of mating two Munchkin cats ends in abnormally small litters and no cats have been examined as homozygous, it has been deduced that the homozygous model is deadly at an early embryonic stage.
The dominant allele is famous Mk for Munchkin cats and the recessive allele is mk for cats with regular limbs. It implies that if the cat is Mk/mk (heterozygote) it’ll have quick legs, whereas whether it is mk/mk, it’ll have regular limbs. Mk/Mk (homozygote) embryos die in utero.
Listed below are some breeding tables to higher perceive the doable mattings:
So, there will be kittens born with regular legs even when each mother and father or one mother or father is a Munchkin: in that case, they’re typically referred to as “non-standard” Munchkins, whereas the short-leg cats are “standard” Munchkins.
Whereas the looks of Munchkin cats is much like the one in all dwarf canine breeds akin to Dachshunds or Corgis, they’ve a special genetic mutation. These canine breeds have a mutation of the fibroblast progress issue 4 (FGF4) whereas munchkin cats have a mutation linked to the gene UDP-glucose 6-dehydrogenase (UGDH). Which means that the well being points current in these canine breeds akin to degeneration and calcification of intervertebral discs can’t essentially be extrapolated to cats.
Well being points
Opposite to different bodily mutations akin to folded ears, the well being results of this mutation have not been extensively studied. A lot of the research on Munchkin targeted (till now) primarily on the identification of the gene because it might have implications to higher perceive some unidentified type of dwarfism in people.
There’s at present just one research analyzing the skeletal manifestation of this mutation. [1] The radiography and magnetic resonance imaging revealed that each one the limbs of the Munchkin cats offered some deformities along with being shorter in comparison with regular cats. Specifically, there was some torsion within the entrance legs of the cats.
Whereas among the deformations could not clinically have an effect on the cats as a result of, as they’re quadruped, they can compensate for some malalignment, others might predispose them to joint illness.
Specifically, related deformations of the forearm have been related to osteoarthritis and luxation in canine.
However, there wasn’t any signal of untimely intervertebral disc degeneration, as it may be seen within the dwarf canine breeds.
Comparaison between a Munchkin on the left and a home cat on the proper from [2]
This research has some limitations and particularly a pattern measurement of solely 6 cats: it highlights that additional analysis is required, notably to know the results of those limb malalignments on the joint well being over the lifetime of a cat. The research was performed on Munchkins with varied leg lengths: the Munchkin breed with the shortest leg could have extra points than longer-legged Munchkins.
Another situations have been anecdotally reported within the breed akin to lordosis, a deformation of the backbone, and pectus excavatum, a hollowed chest. Nevertheless, there aren’t research on these.
To conclude, there may be some proof that Munchkin cats not solely have quick limbs but additionally current deformations and malalignment of their limbs. Whereas it’s not at present clear what the impacts of those deformations are on the long-term well being of those cats, it could predispose them to osteoarthritis. Traits in the direction of cats with extraordinarily quick legs akin to “rug hugger” Munchkins must be particularly scrutinized.
Till a research clearly demonstrates that this mutation doesn’t affect the well being of Munchkin cats, the breeding of those cats shouldn’t be thought of moral or accountable.
Sources
[1] Anderson LM, Fox DB, Chesney KL, Coates JR, Torres BT, Lyons LA. Skeletal Manifestations of Heritable Disproportionate Dwarfism in Cats as Decided by Radiography and Magnetic Resonance Imaging. Vet Comp Orthop Traumatol. 2021 Sep;34(5):327-337. doi: 10.1055/s-0041-1730355. Epub 2021 Jun 3. PMID: 34082456.
[2] Struck, AK., Braun, M., Detering, Ok.A. et al. A structural UGDH variant related to customary Munchkin cats. BMC Genet 21, 67 (2020).
[3] Buckley RM, Davis BW, Brashear WA, Farias FHG, Kuroki Ok, Graves T, Hillier LW, Kremitzki M, Li G, Middleton RP, Minx P, Tomlinson C, Lyons LA, Murphy WJ, Warren WC. A brand new home cat genome meeting primarily based on lengthy sequence reads empowers feline genomic drugs and identifies a novel gene for dwarfism. PLoS Genet. 2020 Oct 22;16(10):e1008926.
[4] Lyons, Leslie & Fox, Derek & Chesney, Kari & Buckley, Reuben & Coates, Joan & Gandolfi, Barbara & Grahn, Robert & Hamilton, Michael & Middleton, John & Sellers, Samantha & Villani, Natalie. (2019). Localization of a feline autosomal dominant dwarfism locus: a novel mannequin of chondrodysplasia.
[5] William-Jones H. Arrested growth of the lengthy bones of the fore-limbs in a feminine cat. Vet Rec. 1944;56(449):131–2.
