Munchkin and Related Breeds

The Munchkin's short legs are due to dominant gene achondroplasia (or, more likely, one of the mimic conditions pseudochondroplasia or hypochondroplasia) which stunts the growth of the long bones and causes them to bow slightly; they are therefore normal-sized cats with short legs. There are two abnormalities associated with the condition. One is lordosis which causes a dip in the spine behind the shoulders and compression of the chest, the other is pectus which affects the chest. There is disagreement over how prevalent these traits are within the breed. Munchkin litters are often smaller than average cat litters, suggesting that some embryos die early and are reabsorbed by the mother (probably where the embryo inherits two copies of the gene). In Munchkins, the skull, spine and pelvis do not seem to be affected and, providing breeders are careful to avoid breeding from cats with lordosis or pectus, hence this form of dwarfism is considered cosmetic.

Genuine miniature cat breeds are a relatively new development in the cat fancy though there are several small cat breeds. Adult Singapura males weigh approx 6 lb (2.7 kg) and females weigh as little as 4 lb (1.8 kg). Some healthy adult female Siamese cats weigh only as 5 lb (2.26 kg) though some male Siamese can reach 20 lb (9 kg). Some Siamese breeding lines give smaller, more "fragile-looking" cats than others and the old-style Siamese cats are more robust than the rather skinny modern version of this breed. The Mei-Toi was once advertised (1990s) as a genetically miniature cat with no accompanying details. Latest information is that the Mei-Toi is now bred with Munchkins as the Mei Toi Munchkin. Of late, a Miniature Cat Register has been set up in the USA, but it is not affiliated with any major cat organisation, nor does it maintain genuine feline pedigrees. It defines cats in terms of height rather than weight (with short-legged breeds being exceptions to the guidelines!) with an adult Teacup cat standing no taller than 5-6 " at the shoulder while a Toy is up to 8" at the shoulder. It considers height a better guideline than weight because weight also depends on the cat's build (this link is provided solely for information and is not an endorsement of the Register; owners should make their own decision as to the credibility, or otherwise, of this or any other miniature cat register.)

American Miniature Cat

Breeding ceased in 2015. Many different breeds wer used to create the REFR's American Miniature, including Manx, Siamese, Persians, and crossbreeds including polydactyl cats. It was approximately half the size of the average housecat, never exceeding 7 lbs at maturity. American Miniatures were not short-legged, but were perfectly proportioned. All colours, patterns and fur types were permitted, along with polydactyl and short-tailed cats. Miniature was defined as no more than 12 inches long (base of neck to base of tail) and no more than 10 inches tall (top of paw to top of shoulder blade) when mature (from 18 months). Cats exceeding these measurements were not bred, even if their parents were miniatures.

Russian Toybob (Skif-Toy-Bob and Skif-Thai-Don)

The Toybob cat is often referred to as one of the smallest of all cat breeds and is a small cat that should not grow any larger than the size of a 6-month-old kitten of a well-developed domestic cat. They have a compact body, well-developed musculature, a relatively deep wide chest, and a short tail that consists of several distorted vertebrae (visible length of 3-7 cm). Because its head and legs are in proportion to the body, it is considered a miniature cat and does not have the same dwarfism as the Munchkin cat. Regardless of their size, they are healthy animals with a rounded wedge-shaped head, low and round cheekbones, a short wide muzzle, and a slight curve to the bridge of the nose. They have a flat plane above the brows, a strong chin, and medium-sized ears set high up and straight. They have large, slightly upwards, slanted rounded eyes. When wide open, eyes can appear larger and rounder. The big-eyed expression is what gives the Toybob its sweet-faced look. There is both a Shorthair and Longhair variety, with Toybob Shorthair more common at this time as not all professional cat associations have yet approved the longhair variety.

The Toybob cat was first documented in the Rostov Region of Russia in 1983 when Elena Krasnichenko adopted a stray seal-point Domestic cat. By her accounts, this cat looked very much like a Traditional Siamese cat, except for its shortened tail. Krasnichenko later bred this male to another stray brought home by her mother, a bobbed tailed seal-point female with an unusual curled kinked tail, and in 1988, the breeding of these two cats produced an unusually small bobbed tail kitten she named "Kutciy," which became the progenitor of the breed, first called Skif-Thai-Don. (also known in the longer form, Skif-Thai-Toy-Don). To this day, Krasnichenko breeds her Toybobs only in the seal-point color and pattern.

By the late 1990s, the Toybob were nearly extinct when a breeder from the Urals of Russia, Alexis Abramchuk of Si-Savat cattery (inactive), begun to broaden the breed's limited gene pool by adding Domestic cats. When Si-Savat discontinued their breeding program, Natalya Fedyaeva of Little Angel cattery (inactive), acquired from Abramchuk, a small male "Gavrila Fadeevich." Elsewhere, she acquired two Skif-Thai-Don females, one being Gavrila's sister and began her expansion of the breed. Fedyaeva had observed that cats of very similar phenotypes to the Toybob were spotted living locally around barns and streets in her region. Some of these native cats were also of small size with kinked tails or kinked bobbed tails but seen in colors and patterns other than seal-point. Fedyaeva, along with other local breeders, began to work on developing the Toybob cat's initially small genetic pool by adding those found domestic cats as well as other similarly phenotyped breeds. Fedyaeva began to refer to her cats as "Scyth-Toy-Bob" to differentiate them from the Skif-Thai-Don. In the 2000s, due to significant differences in breeding plans, the Toybob breed split into the two distinct breed groups from two different regions; the Rostov bred Skif-Thai-Don and the Ural bred Scyth-Toy-Bob. With each breed group promoting a slightly different standard within the cat clubs and shows. A separation that lasts until 2017 when both groups came to the consensus it would be best for the two groups to get together again and drop any form of prefixes from the breed's name, making it easier to unify the breed's standards across all associations worldwide.

The breed has been known under several different names and is a significant component of its history. It was in 1994 when the Toybob name was suggested by WCF judge and feline book (Mironova, O.S. Aboriginal Cats of Russia: From Attics and Backyard To World Recognition. Saint Petersburg. 2003. Print.) author Dr. Olga Mironova be given to all Toybob cats in development. In 2004, Toybobs were imported to the United States by an American Burmese breeder, Mila Denny of Sacredspirit cattery, and four years later, the cats entered Experimental status within The International Cat Association (TICA) under the general name, Toybob. In 2014, the majority of TICA registered Toybob breeders began to work in close cooperation, focusing on advancing the breed's recognition. A year later, led by an official breed club "International Toybob Cat Club" (ITCC) formed, with the dedication to promoting the breed worldwide, mentor new breeders, unify the Toybob standards and advance the breed across all Cat Fancy associations. In 2015, the Rostov-based breed group "officially" changed the name of their cats from Skif-Thai-Don within a couple of other small Russian Cat Fancier Associations to the hyphenated "Toy-Bob," causing some confusion. As aforementioned, in 2017, both groups came to the consensus it would be best for the two groups to unite. At the end of the decade, the breed gains Championship status outside of Russia within two North American associations and Europe's World Cat Federation (WCF) with further work underway in getting the breed to Championship status worldwide.

The Toybob cat's most distinctive feature is it's kinked bobbed tail, and just like other known kinked bobbed tail breeds, the tail does not affect its agility or health. At the time the breed was registered with TICA, little to no genetic research had been done on the breed to learn more about the unique genes behind the Toybob cat's small size and bobbed tail appearance. Leading to much speculation as to it having possible relations to other known bobtail breeds. In 2016, the ITCC decided to perform preliminary testing with the world-renowned geneticist and feline expert Dr. Leslie A. Lyons to find any connection to other bobbed tail breeds. It resulted in there being no Manx gene nor any relation to any other bobtail breed (e.g., Japanese Bobtail, Kurilian Bobtail), and the conclusion was we are dealing with an entire new bobtail mutation. Toybob overall health is rather robust due to the harsh environment from where the breed originated. Also, the continued use of native Russian Domestic cats in the breed development maintains excellent genetic diversity and good health. The breed has no known health or genetic problems and is known to be long-lived even well past 15 years. Although a diminutive cat, the Toybob might surprise some as it carries nice sturdy weight to it for its overall small body. Toybobs are bred in both shorthair and longhair (semi) varieties in a wide range of colors, although pointed colors are the most common.

Feline traits notwithstanding, the Toybob has all of the qualities one looks for in a companion cat. Toybobs thrive when they are with their people. The Toybob is intelligent, good-natured, affectionate, and social, making it easily get along with other friendly animals. Individuals who love the cat can't imagine life without one, and many can't imagine life without two or three.

Before the appearance of these Russian cats, the Singapura was considered to be the smallest pedigree breed in the world.

Miniature and Dwarf Ragdolls

In 2013, I learnt of a line that produces 2 types of dwarf Ragdolls (some dying in infancy) whose closest common ancestors are Sugarpaw Jack Frost of Catastrophe and Sugarpaw Bit O'Honey of Catastrophe (if the 2 types of dwarfism are separate then more recent common ancestors can be found as the Catastrophe cats are close to foundation level and are also behind many, many unaffected lines). Pituitary dwarf Ragdoll "Tiny" was born on the 22nd March 2011; he is very healthy apart from has problems with nasal secretions. At one point, Tiny collapsed and was lucky to pull through. He was tested two years ago for pituitary dwarfism. Tiny was small from day one and his teeth did not come through until he was 18 weeks old. Another Ragdoll breeder had a female pituitary dwarf Ragdoll born in 2012 and shared the same common ancestors with Tiny. Unfortunately, this female dwarf Ragdoll collapsed, and unlike Tiny, did not pull through. In 2013, three more pituitary dwarfs were born. One (a female called “Didge”) was born in March and has the same sire as Tiny. Didge is perfectly formed and has her teeth, but at 4/5 weeks of age, her growth rate had slowed down in comparison to her littermates. She also had very sparse hair and almost translucent skin. In appearance, though not in growth pattern, Didge resembled Tiny. Her full coat came in around 15/16 weeks and she looks like a miniature Ragdoll. In August 2013 (age 23 weeks), she weighed in at 1.7kg while her normal-sized sisters weighed 2.4kg and 2.7kg. The other two dwarf kittens were full-siblings to Tiny. They were part of a litter of five, and the remaining three grew at the normal rate. The dwarfed kittens are a male and a female and share the looks and growth pattern of Didge. By week 8/9, the kittens were lean and slender with large ears. At 14/15 weeks, their full coats developed.

The inheritance pattern currently suggests a recessive gene carried by both of Tiny’s parents and by Didge’s mother, however the owner is arranging genetic tests. Apart from the kittens’ and their parents, it is not known if any other Ragdolls currently carry the gene. So far, all breeding of these dwarf Ragdolls has been to identify where the gene came from and how it is inherited.

In Spring 2016, a different form of dwarfism, a deferred lethal mutation, in Ragdolls was being investigated by the Scandinavian Ragdoll Club. All affected kittens shared a particular ancestor on both the maternal and paternal side of their pedigree which indicated a recessive gene “doubling up.” However there was not excessive inbreeding and the common ancestor may be 8-9 generations back in their pedigrees and is found in many of the popular and common breeding lines which means the gene may be widespread. The common ancestor was ES*Patriarca Gucci (female born in 2001, PG for short). Not all of Gucci’s offspring were carriers which is why a genetic test is important. Despite the wide gene pool, some carriers of the gene have been bred together. By April 2017, there were about 40 dwarf kittens born in Sweden and other countries. The study found that Hvenhildas Rufus , Hvenhildas Rakel and Hvenhildas Ulrik, offspring of Seierø's Prima Donna (Patriarca Gucci's daughter) had not produced dwarf offspring when mated to identified carriers; they were considered low-risk. There was no data about risks from Prima Donna’s other offspring. On average, a recessive gene is transmitted to 50% of the offspring so breeders were advised to avoid breeding Patriarca Gucci’s descendants to each other to avoid possible doubling up.

The "PG" dwarf Ragdolls seen since 2016 had short legs, a short broad body, very short tail, small forward tilted ears, a broad head (almost cartoonishly oval) with a short nose and very dark blue eyes. Many had very small paws and underdeveloped hind legs. They were slow-moving and had a distinctive gait. At birth they were a normal weight, but by 2 weeks old they were obviously slower growing and less energetic than unaffected littermates. After 4-5 weeks old, the differences became gradually more pronounced. Affected kittens also suffered from constipation and did not live longer than 12-16 weeks old. Some kittens were more severely affected than others; the severely affected kittens lived for weeks while the mildly affected ones lived for months. Several were treated with the Levaxin (a drug used to treat congenital Hypothyroidism) and showed increased growth and activity, but died before 6 months old despite treatment. The prognosis is so poor that euthanasia is indicated once a kitten shows signs of this form of dwarfism.

The following forms of dwarfism were ruled out: Mucopolysaccharidosis I, Mucopolysaccharidosis VI, Mucopolysaccharidosis VII, Mucopolysaccharidosis VII (2), Mucopolysaccharidosis VII (3) and Hypothyroidism (1 variant). There were no available DNA tests for other forms of Mucopolysaccharidosis, other LysosomalStorage Diseases or Hypothyroidism in cats. This means the dwarf kittens can be wrongly diagnosed as healthy despite their distinctive appearance and the known incidence of early mortality. In summer of 2016, Project Dwarfism was set up with the Swedish University of Agricultural Sciences (SLU) with the goal of developing a DNA test to detect the mutation so that confirmed carriers can be removed from breeding programmes.

Miniature Persians

As one of the oldest selectively bred varieties in the Western cat fancy, it is perhaps not surprising that miniatures have been reported several times in Persians and Himalayans (Colourpoint Persians). Until recently, miniature Persians were regarded as curiosities only. There are now several catteries (USA, Canada, UK) breeding small-statured Persians, most resulting from progressive downsizing.

Through a selective breeding program begun in the mid 1980's, a breeder from Staten Island, New York, USA progressively "down-sized" Persians and Himalayans to consistently produce genetically smaller versions. Such a program breeds only breeding from the smallest cats of each generation as these carry genes for smaller size (or lack genes for normal size) without being dwarf or midget cats. All other physical features and personality traits reportedly remain the same as their larger counterparts. They are miniature versions of the older type "doll-faced" Persians and the breeders, Mini Isle Cattery of Long Island, New York emphasise that the cats are not miniatures, not runts. The miniaturisation is variable and cats bred vary according to the size they reach at 9-10 months of age. Mini females™ weigh 6-8 lbs and Mini males™ are 8-10 lbs. The Pixie™ females are 4-6 lbs with Pixie™ males weighing 6-8 lbs. The smallest category, Teacup females are a mere 2-4 lbs while the Teacup males are 3-6 lbs. It is not always possible to determine which kittens in a litter will reach which of these size categories. Miniature kittens are more vulnerable (e.g. to temperature fluctuations) than normal sized kittens. Being miniature poses health problems to pregnant cats so the breeding females must be 4-8 lbs in weight and breeding males are 4-10 lbs. Note: Trademarking of the "Mini" prefix may be a problem since this prefix is a standard part of the English language and "Mini-Himalayans" have occurred in the past (unconfirmed reports from Europe).

The other diminutive Persians are Bonnie Arnold's Toy Persians which mature at about 3-5 pounds, compared with the normal 14 pounds. In contrast to the down-sizing breeding program, these are the result of a sudden mutation. Her Teacup Persians and Toy Persians began in 1995 when a spontaneous genetic mutation occurred within the sperm-producing cells of a 14 lb breeding male Persian called "Treker". Treker and his offspring are currently the best documented (in respect of breeding data rather than scientific investigation) cases of feline miniaturisation hence the large amount of information presented here.

In the early 1990s, her prize-winning smoke tortie female was bred to her 14-pound cameo tabby son. This produced 5 kittens of which 2 were noticeably small, something then attributed to breeding close relatives together. The 2 small kittens were neutered and rehomed. The father of this litter, Ch. Nightspell Star Treker, became main stud cat. Treker managed to mate with his own full sister, not a planned or ideal mating, producing 3 tiny kittens which were again attributed to inbreeding. Two were strictly pets, but one had potential yet did not grow despite Science Diet and vitamins. Arnold was certain that 5 small kittens out of a total of 8 kittens was due to inbreeding. Treker was next bred to 2 females to whom he was unrelated. Treker's 3rd litter sired produced 4 normal sized kittens, yet two of the kittens grew at only half the rate of the other two. The same happened to all 3 of the kittens produced by the other female. 10 out of 15 of Treker's kittens had proven to be small therefore Arnold stopped using him as stud and sought specialist advice. Dr. Solveig Pflueger, a noted feline geneticist, suggested 2 test matings to see if the small kittens were flukes, the results of recessive genes or more unlike the result of Treker having a spontaneous genetic mutation in his germ cell resulting in a dominant gene for diminutive size.

The test matings were full-brother sister breeding which had previously produced l00% small cats (therefore recessive genes were suspected), and an outcross to a domestic cat (i.e. not a Persian at all, but a random mix of genes). The brother/sister mating produced a normal large kitten which seemed normal but grew at a reduced rate. Dr Pflueger remained sceptical that a spontaneous genetic mutation would prove responsible for the small size; recessive genes were far more likely. The domestic cat's kittens were 2 normal size males, 1 normal size female, and 2 small females; but all grew into small cats. This demonstrated a dominant gene was responsible, possibly asp-miniaturisation. Later work on the breed also involved a veterinarian in the Dallas area (where the cats are bred), Dr Kent Cooper.

All of the kittens from litters No. 3, 4, 5 and 6 (ranging in age from 6 months to 1.5 years old) were spayed and neutered except for 3 males and for a female too small for spay surgery (this is one of the pitfalls of miniature cats - spay surgery may have to be delayed because of the cats' small sizes). Arnold had no plans to breed the little girl, as a 3 lb cat would have problems delivering and nurturing 4 oz kittens; however the oldest male would be bred to a full-size female.

76% of kittens sired by Treker are miniatures. This indicates a germ-cell mutation - although the stud cat is of normal size, there has probably been a mutation in the cells which produce sperm so that many of his offspring inherit a mutated gene causing the small size. Toy Persians mature at around 5 lb while Teacup Persians pounds maturing at 3-4 lbs pounds with some maturing at less than 3 lbs. Despite their small size, the diminutive cats are have all been perfectly healthy.

In April 2002, after seven years, and five generations, Bonnie's Persians are tiny; some as small as 2.5 pounds at maturity. The picture above shows an miniature adult male and a standard Persian male. Despite their diminutive stature, they are "disgustingly healthy" showing none of the problems their detractors originally warned about.  At present, she is breeding the tiny males to standard outcross females to broaden the gene pool. Matings of tiny-to-tiny have so far produced no negative results.

Above, standing by a cola can for comparison, is a Toy Persian (5 lbs at maturity).   She is a very stocky, cobby, heavy-boned and hefty, properly put together according to the CFA Persian standards, except for her overall size. 

Other lines of Miniature Persians are MiniPers and MiniPaws. MiniPers are Tea Cup and Miniature Persians & Exotics, developed by Cher Simnitt in California. These cats have primordial-type dwarfism (their physical aspects are in proportion), being miniature versions of the Persian/Exotic. MiniPaws Tea Cup and Miniature Persians and Exotics, developed by My Tea Purdys Cattery carry both pseudochondroplasia/hypochondroplasia and primordial-type dwarfism; they are proportionately small except for their shortened legs.

Due to public interest, rather than cat fancy interest, more and more small-sized Persians have appeared since these first 2 lines were documented. As there is no recognised breed standard, different breeders are free to use whatever description they wish for a size or weight range. For example some refer to their miniatures as "palm-sized" or "pocket" Persians and give a weight range of under 3.5lbs (female) and under 4lbs (male), while others refer to "pixie", "mini" or "teacup".