Siamese: The World’s Most Unhealthy Cat!
Despite its esteemed position as one of the world’s most recognisable and popular purebred cats, the Siamese is arguably the most sick of all the cat breeds, indeed of any other cat.
The title is deliberately provocative but the statement is rooted in fact. Here is a chart that lists the inherited diseases associated with cat breeds. Some cat breeds are not represented on this chart. The reason is that there is, as yet, not enough research on this matter and therefore the information is unavailable. Also some cat breeds have no known inherited diseases.

The number of Siamese cat genetic diseases are greater than other breeds
This is the list of genetic (inherited) diseases associated with the Siamese:
- Asthma
- Cutaneous asthenia – 2 types (a) thin skin, or (b) soft velvety skin that is easily damaged.
- Esophageal hypomotility – spontaneous movement of the intestine. The cat regurgitates, is feverish and has respiratory problems.
- Mast cell tumors
- Hypotrichosis – abnormal hair patterns due to thinning.
- Cutaneous mastocytomas – masses under the skin.
- Glaucoma – chronic open-angled glaucoma – increased eye pressure.
- Cervical neck lesions – bad teeth. Siamese cats need dental checks.
- Hip dysplasia – loose hip joint
- Feline hyperesthesia syndrome
- Feline endocrine alopecia
- Mucopolysaccharidosis
- Gangliosidosis
- Adenocarcinomas of the small intestine
- Malignant mammary tumors
- Numerous congenital heart defects (PDA, aortic stenosis, AV valve Malformation, pyloric stenosis, etc)
- Strabismus – squint – the classic. original cross-eyed cat.
- Primary endocardial fibroelastosis
- Nystagmus – rapid eye movements left to right.
- Congenital heart defects
- Hydrocephalus – kittens have a domed shaped head, abnormal gait, depression, head ache.
- Sphingomyelinosis – retarded growth and ataxia (wobbly gait). Head bobbing. Death before one year of age.
- Chronic Degenerative Keratitis
- Hepatic Amyloidosis
When the Siamese cat was first imported from Siam to England, UK in 1886, Mrs Vyvyan of Dover, England, UK, describes the cat as dominant over other cats in the area where she lived. They were strong cats but they suffered from an acute case of worms. The condition was so bad the cats tried to cough them up. Veterinary surgery was hardly in existence and she gave them chicken heads and feathers for relief. An inauspicious start, health-wise.
The high number of genetic diseases associated with the Siamese has not been explained. For me it is caused by over zealous breeding for appearance while placing health as a secondary consideration.
I am referring to the extreme selective breeding that has created the slender and highly “refined” modern Siamese with the bony, elongated head. All breeders will disagree with me. I am fine with that.
Primary Source: Genetic Diseases in Purebred Cats – Source: Medical, Genetic, & Behavioral Aspects of Purebred Cats; Ross D.Clark, DVM.