Animalia Life

The Breed History
About the year 1960 in Devonshire England, a stray was found to carry this new "rex haircoat" gene. The first progenitor male was named Kirlee. This mutation is not related to Cornish Rex or Selkirk Rex and early crossings between them proved this; though some of these crossbreds were used in the early Devon Rex breeding program. The Devon Rex haircoat (re) is an autosomal recessive gene affecting normal hair follicle development. The Devon Rex is more waved than curly haired; the latter being the type seen in the Cornish Rex. In 1967, the GCCF in Britain and FIFР№ in Europe accepted the breed. The CFA recognized Devon Rex as distinct from Cornish Rex in 1979, put the Devons into the provisional class in 1981, and championship status was granted in 1983. In 2013 outcrossing will no longer be allowed; until then, The Devon can be crossed with British Shorthair and American Shorthair cats only.

Physical Characteristics
Weight: 6-9 lb (2.5-4 kg)
Coat: Can be any color since hair mutation and color are not linked. The ventrum may be downy and of reduced hair density, but the texture of the coat is silky and fine like crushed velvet, and bare patches are penalized except the temples and ears. The coat overall is less dense than a Cornish Rex coat and is whirled or curled, crinkly rather than wavy, and about 1/2" long. The coat is very short, very soft and the hairs are fine; though normal guard hairs are lacking over the body, on the tail some full guard hairs may make the haircoat a little coarser there. Hair cover on the limbs and head, abdomen, and neck is less curly and shorter. Brow and whiskers may be crinkled, and whiskers and coat hairs break easily. Whiskers are usually less than 1 in (2.5 cm) long. In kittens, waves are not fully developed and coat is not mature until about 16-24 weeks of age, with molting during development, though mature coats can sometimes be significantly delayed in re-growth, finishing well past sexual maturity. Rarely, longhairs are born.
Eyes: Large oval eyes can be any color and are wide set.
Points of Conformation: The head is a short modified wedge with a distinct break. Prominent cheekbones, and well defined whisker pads are evident. Other features include a moderately short nose, very large rounded ears which are set low, lending the cats an elfin look. The neck is fine. The tail is long and slender. Legs are long, straight and medium in bone. Paws are small and oval.
Grooming: Low shedding is standard for this breed. Devon cats have minimal grooming requirements. A light chamois or a hand is used to gently rub over the cat as needed. Not advised to blow dry. Oiliness in the coat can be controlled with chamois grooming but periodic bathing may be required. Ears tend to be greasy and require more regular cleaning than the average cat.

Recognized Behavior Issues and Traits
Reported breed characteristics include: Talkative but with quiet voice, playful, love to climb high and a cat tree and high perches help to keep the Devon exercised. They love warm places and are well suited to apartment life. Devon Rex cats like to play fetch and are active pets overall. Very people-oriented; can be lap cats and can demand attention.

Normal Breed Variations
They are not hardy in temperature extremes. These cats will nurse their young longer than most cats. They tend to gain weight easily. They have naturally waxy ears, so may require more frequent cleaning than the average cat.
Blood Type B: In a study of blood type distribution in the US, Devon Rex cats (n=100) had 43% type B blood. A prevalence of 41% type B was reported in another reference.
Devon Rex Kitten Information Project:3 An internet based survey was carried out to gather breed normal data. Data were for 30 breeders, 103 litters with 377 kittens. June 2001-May 2002.
Average litter size 3.7
Stillbirth rate 4%
Dystocia 8% (1% of affected queens required C-section)
Average birth weight: Male 88 g female 83 g
Congenital deformities occurred in 12.4% of litters, 2.3% born with umbilical hernias, others defects reported included flat chest, and cleft palate.

Drug Sensitivities
None reported in the literature

Inherited Diseases
Multiple Vitamin K-dependent Blood Coagulation Factor Deficiency: (Vitamin K-dependent factors II, VII, IX, X) (Breeder SYN: hemophilia). This condition has only been identified in the Devon Rex breed so far. The cluster of Devon cats in one report from Australia had a range of normal clotting profile/clinically normal findings, abnormal clotting profile/clinically normal, ranging to abnormal profile/abnormal clinical status. Clinical cases presented with signs such as hematoma and conjunctival hemorrhage, post-operative bleeding, sudden death due to intra-thoracic hemorrhage, and it was reported that some had untested relatives (such as littermates) affected or that had died. The screening of cats revealed PT and APTT tests were substantially prolonged. Multiple Vitamin K-dependent blood coagulation factor deficiency was found in another report of two littermates with bleeding tendency. An underlying mutation in the vitamin K-dependent Оі-glutamylcarboxylase enzyme was identified as the reason for the bleeding disorder; this enzyme plays an important role in reconstituting Vitamin K in the liver cycle. A report in a British Devon Rex cat indicated that the same coagulation factor deficiency combination was again present. Another cat with the same grandmother also died of post-operative hemorrhage. The cats responded to oral/subcutaneous vitamin K administration and transfusion. A likely autosomal recessive inheritance was reported. Age of onset is generally before one year of age. It is important to note that not all reported afflicted cats had clinically evident bleeding episodes. The prevalence of this defect is unknown in the breed, so testing Devon Rex cats by coagulation profile before surgery might be prudent until further data is available.
Devon Rex Hereditary Myopathy (Breeder Synonym: Spasticity): A neuromuscular disease leading to muscle weakness, and is similar to limb girdle muscular dystrophy in humans. First reported in 1974, this condition presents as an unusual gait (high stepping), significant neck ventroflexion, head bobbing, limping, abnormal mastication due to pharyngeal muscle weakness, megaesophagus, difficulty drinking (nose may be inserted underwater), dorsal scapula protrusion, shaking, and collapse. Aspiration pneumonia or sudden death due to choke is a possible consequence of difficulty with prehension of food and water. Neck ventroflexion may worsen during micturition and defecation and while walking, and signs may wax and wane in intensity over days to weeks.9 Blood count, serum biochemistry including CK and electrolytes are all within normal ranges. Histology is best performed on proximal limb and cervical muscles, and magnitude of changes is correlated with age and severity of clinical signs at time of biopsy. Age at onset of signs varies but signs are often noted by breeders at 4-7 weeks, though some are delayed to about 13 weeks of age (range of onset 4-20 weeks). Though afflicted cats usually worsen, as an adult some may adapt to the disability. In a survey of cats from the UK, Australia, and New Zealand an autosomal recessive monogenic pattern of inheritance was proposed to explain the trait.8 A recent report indicates that dystroglycan (DAG1) may be the gene causing this problem, and the researchers have attempted to sequence the mutation; apparently the same mutation is present in Sphynx Spasticity. Newest studies term this Dystroglycanopathy (muscular dystrophy): This disease results in a loss of glycosylated alpha-dystroglycan expression, but not reduced binding.
Cervical Ventroflexion: In a study carried out in Great Britain, primary muscle weakness was diagnosed in young cats, with marked neck ventroflexion and normal Creatine Kinase and muscle biopsies. No therapy was found to be helpful.
Hypotrichosis: Thin hair regresses to baldness at 2 weeks old. May re-grow by 6-10 weeks of age, but loss occurs again at sexual maturity leaving cats permanently bald.14 It is thought to be an autosomal recessive mode of inheritance. Hair follicles are hypoplastic and hairs are in telogen.
Hereditary Deafness: Is associated with the dominant gene for white cat (W); may be found in white cats of this breed.
Neonatal Isoerythrolysis (NI): High prevalence of B blood type makes this a concern in this breed; typed parents are now the standard for breeders. Published proportion of matings at risk for NI is 0.24 for this breed.16 Also given as 0.246. All B type cats have circulating anti-A antibodies and even primiparous queens can carry these. Type B queens bred to type A toms can result in fatal red cell lysis in A blood type offspring with undetected NI. Kittens with NI can be distinguished from other fading kittens because of pigmenturia; anemia and icterus will also be present; not all kittens at risk for NI will develop overt clinical symptoms.

Disease Predispositions
Transfusion Reactions: Due to high prevalence of blood type B, natural allo-antibodies markedly increase the risk of transfusion reactions so donors and recipients should be blood typed.
Toe and Skin Fold Greasiness, Paronychia: Seborrheic dermatitis caused by M. Pachydermatis is more common in the breed (90% samples positive in a cross sectional survey comparing Cornish and Devon Rex cats with DSH cats). In a study the previous year, the same researchers isolated M. sloffiae from claw folds of seborrheic cats. Another study by the same authors that year explored the use of itraconazole to treat this seborrhea in a 21 day pulse treatment.
Hypertrophic Cardiomyopathy (HCM): The most common cardiac condition in cats (10% prevalence). Suspected to be inherited in the breed, and cats with HCM should be removed from the breeding pool.
Medial Patellar Luxation (MPL) and Hip Dysplasia (HD): Historically, a proposed genetic predisposition to patellar luxation was reported, with hip dysplasia prevalence also increased in this breed. In 1985, it was one author's early finding that prevalence of MPL was apparently much greater in the Devon Rex. A nonrandom group of 78 cats of different breeds including 25 Devon Rex cats were assessed. About 32% of this group of cats and 40% (10 of 25) of Devons had HD using OFA-like criteria and a positive correlation between joint laxity, DJD and HD was identified.The majority of cats were not clinically lame, but diagnostic imaging tests showed pathologic changes. The Devon Rex cats were affected more severely and with higher frequency than the average cat. In the pooled all-breed group with MPL in the study group, those with MPL were three times more likely to have concurrent hip dysplasia than those without MPL. In the 1999 study done at University of Pennsylvania joint laxity measures included Norberg angle (NA), distraction index (DI)] as well as OFA criterion. Some degree of MPL was found in 58% of pooled cats and concurrent MPL and HP in 24%. Of the 25 Devon Rex cats, 16 had MPL (64%); eight Devon Rex cats had both HD and MPL (32%). Both HD and PL are more common than was previously presumed. Medial patellar luxation is thought to be congenital and can be unilateral or bilateral. Higher prevalence of MPL is suggestive of a hereditary basis.
Dystocia: A report summarizing a survey of 2,928 litters that included multiple cat breeds was analyzed to ascertain prevalence of dystocia, and over-representation of Devon Rex cats was found (22 Devon litters analyzed). Average dystocia rate in the study group was 5.8% of litters, with a low in mixed breed cat colony of 0.4%, to a high of 18.2% in the Devon Rex study group.

Rare and Isolated Reports
Amyloidosis: Hepatic rupture in association with systemic amyloidosis was reported in a Devon Rex cat. Hepatic amyloidosis has not previously been reported in this breed. Prior reports involved Orientals, Siamese, and primarily renal amyloidosis in Abyssinian cats.
Feline Urticaria Pigmentosa (papular eosinophilic/mastocytic dermatitis): Very similar to the condition described in Sphinx cats (as Urticaria pigmentosa-see Sphynx chapter) and in young Himalayan cats. Pruritis, wheals, and red-brown papules are termed cutaneous mastocytosis in humans; is also associated with eosinophilic infiltration.
Five unrelated Devon Rex cats aged 5 months to 4 years of age were afflicted with very specific dermatologic changes which waxed and waned over a period of 3 weeks, to many months (up to 10). Variably pruritic or non-pruritic wheals progressed to erythematous, normal or hyperpigmented crusted macular and papular lesions; some had seborrheic erosive dermatitis, others secondary pyoderma (pyoderma was associated with hyperpigmentation and pruritis). May be closely related to the other eosinophilic hypersensitivity disorders such as plaque and granuloma and may be an allergic hypersensitivity response or propensity.
FIP Susceptibility: An American study found that Rex cats were significantly over-represented for a diagnosis of FIP when they analyzed data for a 16 year period at a veterinary teaching hospital.
Recurrent Syncope: A case report described a cat that had 7-year history of recurring syncopal episodes that were associated with paroxysmal supraventricular tachycardia (SVT) and was diagnosed using an implantable loop recorder, and treated with sotalol.
Swimmer Syndrome: After several weeks, a 3-week old showed response to bandaging and physiotherapy. Euthanasia is the usual veterinary recommendation for this condition.

Genetic Tests
Coagulation profile and blood typing before surgery, transfusion, or in breeding animals is recommended. Though no program is recommended in the literature, screening breeding animals for HD and MPL using radiography and orthopedic examination may be helpful to manage these conditions in the breed.

Miscellaneous
- Breed name synonyms: Curly-coated cat, Devon, Rexed cat, nickname: Poodle cat
- Registries: FIFe, TICA, CFA, ACFA, CFF, CCA, NZCF, WCF, ACF, GCCF
- Breed resources: Devon Rex Breed Club: http://www.devonrexbreedclub.com/
The Rex Cat Club (GCCF-U.K.): http://www.sam.luxford-watts.zen.co.uk/home.html
Rex Breeders United:
446 Itasca Ct NW
Rochester MN 55901