Cat breed · Siam, Thailand
The Siamese cat (Thai: แมวไทย, Maeo Thai; แมวสยาม, Maeo Sayam; แมววิเชียรมาศ, Maeo Wichien Maat) is one of the first distinctly recognised breeds of domestic cat. It is selectively bred since the end of the 19th-century from the Wichianmat landrace, one of several varieties of cats native to Thailand (known as Siam before 1939), and is pedigreed in all major cat fancier and breeder organisations. Siamese cats have a distinctive colourpoint coat, resulting from a temperature-sensitive type of albinism. Distinct features like blue almond-shaped eyes, a triangular wedged head shape, large wide-set ears, an elongated, slender, and muscular body, and various colours of point colouration characterise the breed.
The breed was one of the most popular cat breeds in Europe and North America in the 19th century. Around the 1950s, the modern-style body with slender and angular features became the preferred type by Siamese enthusiasts. From the 1980s onwards, the traditional "old-style" (rounder-built) cats started to officially split off from the (modern-style) Siamese breed and were re-established by multiple registries as the separate Thai cat breed. The terms "Siamese" or "Thai" are used for cats from these specific breeds, which are by definition all purebred cats with a known and formally registered ancestry, also known as the cat's pedigree or "paperwork".
The Siamese is used as foundation stock in several new cat breeds; by crossbreeding them with other cats. The Oriental and Col
Behaviour: Siamese are usually very affectionate and intelligent cats, renowned for their social nature. Many enjoy being with people and are sometimes described as "extroverts". Often they bond strongly with a single person. Myrna Milani describes the Siamese as being more diurnal, more likely to stay close to their owner, and less likely to hunt than other cats.
Appearance: The breed standard of the modern Siamese calls for an elongated, tubular, and muscular body and a triangular head, forming a triangle from the tip of the nose to each tip of the ear. The eyes are almond-shaped and light blue, while the ears are large, wide-based, and positioned more towards the side of the head. The breed has a long neck, a slender tail, and fur that is short, glossy, fine and adheres to the body with no undercoat. Its pointed colour scheme and blue eyes distinguish it from the closely related Oriental Shorthair. The modern Siamese shares the pointed colour pattern with the Thai, but they differ in head and body type.
Many foundation stock cats from Thailand had a kink in their tails, but over the years, this trait has been considered a flaw. Breeders have largely eradicated it around the 1950s, but the kinked tail persists among street cats in Thailand.
Health: Based on Swedish insurance data, which tracked cats only up to 12.5 years, Siamese and Siamese-derived breeds have a higher mortality rate than other breeds. 68% lived to 10 years or more and 42% to 12.5 years or more. The majority of deaths were caused by neoplasms, mainly mammary tumours. The Siamese also has a higher rate of morbidity. They are at higher risk of neoplastic and gastrointestinal problems but have a lower risk of feline lower urinary tract disease. A UK study of veterinary records found a life expectancy of 11.69 years for the Siamese compared with 11.74 years overall.
The same albino allele that produces coloured points also results in abnormal neurological connections between the eye and the brain. The optic chiasm has abnormal uncrossed wiring; many early Siamese were cross-eyed to compensate, but like the kinked tails, the crossed eyes have been seen as a fault, and due to selective breeding the trait is far less common today. Unlike many other blue-eyed white cats, Siamese cats do not have reduced hearing ability.
The Siamese suffers from abnormal visual projections due to the lateral geniculate body of the eye differing from normal felines. Fibres located in the temporal retina cross over in the chiasm instead of remaining uncrossed. The breed has also been found to have a predisposition to progressive retinal atrophy.
The Siamese is predisposed to periocular leukotrichia, pinnal alopecia, and psychogenic alopecia.
Young Siamese cats are predisposed to histiocytic cutaneous mast cell tumours.
