Animalia Life

The Breed History
This breed is thought to have originated in Rangoon, Burma (now Myanmar) where brown cats referred to as "Rajahs" were documented. Thai 16th century writings portray similar cats. In North America, the foundation dark sable female named Wong Mau was brought over to California in the late 1920s. She is believed to have been a Tonkinese (Burmese-Siamese cross). Modern Burmese cats are thought to derive solely from Wong Mau. Her offspring were of three coat types; the type with sable coloring was selected for the next generation.
The American Burmese type is distinct from the European Burmese. The latter is found in Europe, Australasia and South Africa and is a much more angular cat-the head is more wedge shaped and these cats are longer, and lithe in build. Additional colors are accepted in non-CFA registries-those other colors were termed Malayan in the USA. The CFA considers the American and European as two breeds. In the American fancy, the Burmese is further subdivided into Traditional cats, with more elongated head and the Contemporary cats, with a rounder more brachycephalic head. The latter gained popularity in the 1970s. No outcrossing is allowed in CFA.
The CFA accepted the Burmese breed in 1936, disallowed them for a while, and again reinstated them in the early 1950s, with full championship status by 1957. Only sable coloring was accepted by CFA until the late 1980s, at which time the accepted color spectrum was expanded to four colors. Malayans were separately registered from 1979-1984.
Burmese cats have played a role in development of other breeds incuding the Burmilla (Chinchilla Persian X Platinum Burmese), Tiffany (Longhaired Burmese), Bombay (Black Shorthair X), and Tonkinese (Siamese X).

Physical Characteristics
Weight: 8-13 lb (3.5-6 kg); females smaller than males Coat: A distinctive breed characteristic is their very high gloss and thick close-lying shorthaired coat; satin-like in texture. Colors include sable (also termed usual, or brown), frost or platinum (lilac), champagne (honey-beige), and blue (a warm grey color). Minimal undercoat is present. All coat colors are lighter on the ventral aspect of the cat and darker fur is often found around the face (mask), tail, feet and ears. The mask and points should be minimal in mature cats. Burmese sable points are recessive (cb cb). Young sable cats will darken as they mature.
Eyes: They possess large yellow or gold eyes, round in shape. In CFA, green eyes penalize and blue eyes disqualify. The FIFe registry allows green eyes.
Points of Conformation: Conformation is similar to the Bombay cat, though Burmese are smaller, lighter in build and the rounded head is proportionately smaller. A medium-small sized cat; compact and heavy for their size, the Burmese's round head shape and nose break conformation is a breed characteristic. The body is short-coupled, the medium length tail is fine and tapers, whisker pads prominent, muzzle is short-medium, ears are medium-small, and round tipped. The feet are small, and round-oval. Most points of the cat's conformation are round.
Grooming: Low grooming needs are required for Burmese cats-just a hand or chamois wipe or soft brush weekly.

Recognized Behavior Issues and Traits
Reported breed characteristics include: Calm friendly temperament, intelligent, adaptable, love climbing, and playful as youngsters. May enjoy playing fetch, are very placid as mature cats; many are a lap or shoulder cat, thrive on human companionship, and they love warm places. Tend to follow their favored people around; some refer to them as "Velcro" kitties. Not particularly vocal; considered a quiet voiced cat. Good with children, seniors and pets. Not suited to outdoor lifestyle. Though uncommon, a few have a strong personality.

Normal Breed Variations Epiphora: Secondary to face conformation rather than due to any unusual anatomic defects in the lower punctum.
Blood Type: Prevalence 100% A type was reported in American cats.
There may be some differences in geographic distribution of blood types; in a very small survey in the UK, of 10 cats tested, one was type B blood.
Good longevity
Good mothering ability
Males/stud cats easygoing
Burmese Kitten Information Project An Internet based breeder survey was carried out to establish normal baselines for reproduction.
Reported: 67 reporting breeders, 206 litters. 927 kittens, June 2003-May 2004.
Average litter size: 4.5
Stillbirth rate: 8.7%
The stillbirth rate was higher in Contemporary subtype (12%), otherwise 7%
C section rate: The rate was higher in the European (11%) than in the others (<1%)
Average birth weight: Male 86 g, female 81 g
Congenital deformities: About 3% were Flat-chested (48% of flat-chested kittens did not survive to four weeks of age), also found craniofacial deformity, dermoids, cherry eye.

Drug Sensitivities
None reported in the literature

Inherited Diseases
Craniofacial (mid-facial) Deformity (breeder SYN: head defect): Over the last few decades, concerted efforts by breeders has resulted in the near elimination of this deformity, but it is of interest to the reader as an example of a genetic disorder linked to a perceived desired phenotype.
An inherited lethal deformity; homozygous status results in some kittens needing early pediatric euthanasia, as well as in utero mortality. Use of Burmese carrier cats in Bombay and American Shorthair breeding programs has resulted in a low frequency of the trait in those breeds also. Prevalence of this disorder has dropped considerably due to breeder efforts to eliminate the gene from the breed. Introduction of this defect coincided with the development of a very "round" emphasis in the American show ring; also termed the contemporary, new look, or eastern look. By the mid 1980s, almost 100 kittens from a number of catteries were afflicted, and efforts began to reduce the deformity prevalence.
The autosomal recessive gene controlling the deformity is not in direct genetic linkage to the head phenotype, though the contemporary facial features are a strongly associated trait. Researchers continue to try to characterize the gene structure.5 It should be noted that the more contemporary head phenotype seems to sort as an incomplete dominant, and that a contemporary phenotype head type cat of recent development may or may not carry the gene for the head defect.
In an early report of one cattery, the condition was described as a complex of craniofacial abnormalities with hereditary meningoencephalocele and it was proposed that the autosomal recessive gene (mc) had incomplete penetrance because homozygotes sometimes did not express penetrated lethality-based on pedigree studies.6 Malformations resulting from early embryonic defects in rostral neural tube closure include duplication of most of the maxillary processes derivatives including canine teeth and whiskers pad area, agenesis of medial fronto-nasal prominence derivatives, and meningoencephalocele (telencephalic). Secondary ocular degenerative processes may also occur.
Nasal dermoids are also seen in some cats. These are also seen in American Shorthairs carrying this gene. A shallow longitudinal furrow of tissue or different color running along the nose has been found in almost 90% of American Shorthair carrier cats, and may be a phenotypic marker of a carrier, though sensitivity and specificity of this finding is not very high.
Agenesis of Nares: Associated with dyspnea, mouth breathing, and snoring.
Epibulbar Dermoids: Usually located in the lateral angle of the eye. They are circular, hairy, and may involve the skin, bulbar conjunctiva and palpebral margin. May also have concurrent internal eye defects, so ophthalmoscopic and biomicroscopic examination should also be carried out in affected cats.
Eyelid Agenesis: Frequently limited to upper and lateral eyelids.
Eyelid agenesis is the most common congenital eyelid defect in cats.
Hypokalemic Polymyopathy: This is a chronic episodic condition of muscle weakness. It has been reported in cats from the U.S.A., Britain, New Zealand, and Australia. Though it was suspected to be inherited, the mode of inheritance was unknown as of 1995.11 Recently, it was putatively suggested to be an autosomal recessive trait.12 Attacks are often transient. In humans, a similar condition called familial hypokalemic periodic paralysis occurs, and at a cellular level and it is thought that these conditions are similar. A series of 18 cases of episodic hypokalemia episodes in related kittens aged 2-6 months old was reported. About half of the cats had full resolution of the condition.13 In another report, in addition to usual signs of weakness and neck ventroflexion, hind limb lameness, knuckled forelimbs and hind limbs, and abnormal hunched sitting posture were noted. These kittens were induced to have attacks of varying severity by exercising; resultant attacks lasted two to three weeks; youngest were 12 weeks old, oldest cat was 1 year of age; most were clustered around the age of 3-4 months. This condition may resolve without treatment; very high creatine kinase and low serum potassium were evident; changes mirrored the attack temporally. Breeding cats with this condition is not recommended.

Disease Predispositions
Renal Failure: Renal failure rate for the Burmese was more than double baseline in a study of cats from 23 veterinary colleges from 1980-1990 (189,371 cases in Purdue University Veterinary Medical Database) at an odds ratio for risk of 2.07:1 (2.45% prevalence).
Diabetes Mellitus (Type 2): An early study of North American Burmese cats in a pooled study group of 333 cats with diabetes did not identify a breed predisposition in that population. In another study in Australia, a breed predilection was established in a study group (n=4402) monitored over a 22 month period. Burmese cats accounted for 20% of diabetic cats of known breed, even though the population of Burmese was only 7% of the normoglycemic cat population.
In a 2004 review paper, in NZ, Australia, and the UK, the frequency of diabetes in Burmese was reported to be four times that of domestic cats, with 1:50 afflicted (compared to <1:200 domestic cats). In Burmese cats 8 years of age and older, the reported rate was 1:10. In some families over 10% of Burmese offspring developed diabetes.
If this is a genetic disorder, the mode of inheritance remains unknown; it is thought that mutation of genes that affect insulin sensitivity are responsible for the breed predilection. Most affected cats are over 6 years of age, with peak incidence at 12 years of age. Other factors that can enhance risk include low activity, obesity, dental disease and a high carbohydrate/low protein diet. It is interesting that Burmese cats put weight on in the internal abdomen first (this is a risk factor for people with that same propensity).
In a recent study in Australia over 5 years, in 12,576 cats of all breeds, prevalence was 7.4:1000 cats and 22.4:1000 for Burmese cats.
Flat-Chested Kittens: A series of young Burmese kittens in the U.K. was reported to have an increased risk of a flat-chested condition in the pediatric phase. Dorso-ventrally flat-chested kittens were usually born with normal phenotype, and then developed a form of chest deformity somewhat similar to pectus excavatum by about nine days of age. About 3%-4% of Burmese kittens were affected. The condition ranges in severity from mild and transient-to a severe form, sometimes overlapping with concurrent pectus. Signs include poor weight gain, cranial thoracic vertebral kyphosis, vomiting, dyspnea, cyanosis, exercise intolerance and cough. Though recognized by breeders, flat-chested kittens have not been widely reported in the literature. Litter viability was 76% in one study of affected litters. In cats in this UK study group, both queens and kittens had higher levels of whole blood taurine than typical reference cat levels.
Kitten's levels in turn were significantly higher than the queens. Taurine has a negative effect on skeletal muscle contractility (hyperpolarization and anticholinergic effect) and this muscle weakness may contribute to the condition. Often as kittens mature and the rib cage calcification completes, the clinical signs abate in many that were less severe and thus not euthanized in the neonatal period. The paper did not elucidate further an established link between hypertaurinemia and the flat-chested condition.
Presence of a dorsal spinal curvature, prominent horizontal rib ridge, and minimal dorsal deviation of sternum into the thoracic cavity in flat-chested kittens distinguish this condition from pectus excavatum.
Calcium Oxalate Urolithiasis: This is one of the breeds identified as having a higher risk of developing this type of stone;
Burmese cats were also reported to have lower risk of magnesium ammonium phosphate (struvite) uroliths.
Wool Sucking: Onset is usually after weaning, this condition also affects other Oriental breeds. Target is commonly a blanket, sweater, socks; often the behavior terminates at sexual maturity, but some cases may have late onset or continue signs late into life. In one report 28% of fabric eating cats were Burmese breed in a group of 152 affected cats. Wool sucking is a stereotypic oral movement and though many cats begin by selecting wool as a substrate, many go on to other types of fabric and even non-fabric substrates such as plastics. Early-weaned cats are over-represented but there is no clear causal relationship.
Corneal Sequestration (Synonym: Black body or cornea nigrum): A condition with unknown cause, found more commonly than expected in this breed. Lesion is usually in central or paracentral cornea. A brown to black pigmented lesion is frequently surrounded by a loose collarette of poorly adherent corneal epithelium. The lesion may extend into mid or deep stroma; even to Descemet's membrane. Sloughing and corneal healing may take 2-6 months; surgical debridement is an option for deeper lesions.
Can be unilateral or bilateral but is most often unilateral; is a corneal stromal necrosis. Topical glucocorticoids are contraindicated; some cases may be linked to feline herpesvirus infection. If virus is suspected, a PCR on excised black body tissue may be helpful. Recurrences or involvement of the second eye in a previously unilateral lesion may occur. In early phases, an amber colored corneal stromal opacity may be noted. It gradually develops distinct raised borders; and the surrounding cornea is cloudy with neovascularization; chemosis, blepharospasm, mucopurulent ocular discharge and hyperemic conjunctivae may also be noted. The surface of sequestrum does not stain with flourescein dye but does retain Rose Bengal stain. Exophthalmic/brachycephalic head conformation is thought to play a role in susceptibility. May recur months or years later, or in a unilateral case the second eye may become affected.
Feline Dilated Cardiomyopathy (DCM): Increased breed predisposition to DCM and decreased risk of hypertrophic cardiomyopathy is reported in Burmese cats. Case levels have dropped since dietary supplementation with taurine began. Previously, mortality for DCM was about 85% and with taurine supplementation the mortality is 30%-50%. Feline signs are not typically a cough as in the dog; heart rate may be bradycardic to tachycardia and both ventricles are affected. Affected cats are prone to arterial thromboembolism. Systolic heart murmur, or diastolic gallop can often be heard, and 61% have arrhythmias, usually ventricular.
Propensity to FeLV Infection: Endogenous feline leukemia (enFeLVs) were studied in a single specimen of Burmese, Egyptian Mau and Persian breed cats to determine how many loci proviruses were typically inserted. This may indicate genetic propensity for leukemia genesis in these cats when exposed to the exogenous feline leukemia virus.
They found provirus on 12/18 autosomes, with an average 19 autosomal copies per cat. One specific locus contained both homologues in all 3 cats. They were also found on both X and Y chromosomes.

Rare and Isolated Reports
Primary Glaucoma: Primary glaucoma is rare in cats when compared with dogs and humans. Findings in narrow angle glaucoma may include a moderately mydriatic pupil, reduced PLR, episcleral blood vessel congestion and buphthalmos. In a study of a small group of affected cats (1996-2001), closed or narrow irido-corneal angles, with reduced number and size of pectinate ligaments, and increased IOP were identified. Tapetal hyper-reflectivity, attenuated retinal vasculature and sometimes optic disc cupping occurred. This condition is still very rarely reported, but an early indication is that this breed may be somewhat predisposed to narrow angle glaucoma. With early diagnosis and appropriate therapeutic intervention, vision may be optimized. Routine screening of this breed may be deemed an appropriate wellness strategy.
In a study of 1100 cases of feline glaucoma from 1992-2006, researchers found 8 cases of primary glaucoma, and of these eight, six were domestic cats and two were Burmese cats-no other purebreds were identified in that sample.
Transient Opacity-Aqueous Humor: Suspected triglyceride rich material accumulated in Burmese cats less than one year old that had no other discernable health problems. Spontaneous recovery occurred within a day, a few recrudesced (2/6 cats).34 Four additional cases were reported in that same year. Two were littermates.35 It is not known whether this represented isolated cases of reaction to a foreign stimulant. Lipid aqueous humor changes are reported to be associated with hyperlipidemia according to a recent report.36 A 2009 report proved that Burmese cats of the Australian strain have reduced triglyceride clearance when compared to domestic or other pedigreed cats. Resting levels were normal. This study may shed light on altered fat metabolism in this genetic pool of Burmese.
Severe Transient Hyperlipidemia and Anemia: In a study group of 12 litters of kittens of weaning age this condition was described; one of the litters was Burmese. A genetic defect in lipid metabolism was suspected.
Endocardial Fibroelastosis: Reports in the older literature (1982) described a very rare condition where the endocardium was markedly thickened in a series of offspring from one Burmese queen and tom. This was thought to be an inherited disorder, characterized by diffuse fibrous and elastic thickening of the endocardium; the left side being dilated and hypertrophied concurrently; tachycardia, CHF, gallop or systolic murmur and terminal cyanosis and dyspnea were noted with onset at 3 weeks to 4 months of age.
Persistent Atrial Standstill: Bradycardia non responsive to medical management and a pacemaker may be needed.
Synovial Osteochondromatosis: Burmese cats are overrepresented, and this condition can be confused with benign periarticular ossification, perhaps resulting in underreporting.
FIP Susceptibility: Feline leukocyte antigen class II is important for control of immune response, and is represented by a set of genes, and polymorphism may play a role in susceptibility; further studies are needed. Burmese cats may be particularly susceptible to FIP. It was noted in this small study sample that related cats of this breed had fewer alleles compared to other breeds.
Another study in Australia confirmed that the Burmese breed cats were over-represented and that they were more likely to develop dry FIP versus effusive FIP.
An American study did not find that Burmese cats were over-represented for diagnosis of FIP when they analyzed data for a 16 year period at a veterinary teaching hospital.
GM2 Gangliosidosis: See the Korat chapter for more detailed information about this condition. A GM2 gangliosidosis lysosomal storage disease with beta-subunit of hexosaminidase enzyme was reported in European Burmese cats. This condition is fatal. Accumulation was noted in brain tissue.
A group of European breeders have formed the DEG or Data Exchange Group to share testing information. The mutation is a deletion (cytosine in HEXB).
Medial Patellar Luxation: A very small study case reported that of eight clinically normal Burmese cats assessed as part of a larger study, two had abnormal patella seating with easily induced luxation. Compared with non pedigreed cats where the rate was two abnormal cats out of 31 cats, they were overrepresented.

Genetic Tests
Burmese coat genes are the least extreme of the ts-tyrosinase partial albinism allele series. The mutation has been identified in the code for tyrosinase enzyme.
New research shows that the c(b) allele of the albino locus gene are variants on the D1 chromosome specifying tyrosinase.and the chocolate (b) and cinnamon (b(9l)) a second allele at the B (brown) locus are nucleotide variants of TYRP1 (chromosome D4).
The mutations are reported to most likely to be identical by descent rather than multiple mutation events occurring at the same site in another study.
Glaucoma Screening: Ophthalmoscopic exam, gonioscopy, and tonometry are recommended for breeding stock. Renal Function: Screen for renal function (minimum of Creatinine/ BUN and urinalysis) in cats eight years and older since a breed propensity to renal failure was identified.
Scott-Ritchey Research Center web site at vetmed. auburn.edu/srrc and UC-Davis VGL for Gangliosidosis GM2 testing in European Burmese

Miscellaneous
- Breed name synonyms: Historically, dilutes were registered in CFA as Malayan cats-they are now accepted as Burmese in separate class
- Other Synonyms: Burm, Thai Copper Cats, Asian Shorthair
- Registries: FIFe, TICA, CFA, ACFA, GCCF, ACF, WCF, NZCF, CCA
- Breed resources: United Burmese Cat Fanciers: unitedburmese.com/
The Burmese Cat Club: burmesecatclub.com/
The Burmese Cat Society: burmesecatsociety.org.uk/
National Alliance of Burmese Breeders (CFA): burmesecat.org/