Genetic Health Risks in Oriental Cats: Understanding Amyloidosis and PRA

Short answer: the two inherited conditions most often linked to Oriental cats are amyloidosis, in which abnormal protein builds up in organs such as the liver and kidneys, and progressive retinal atrophy (PRA), which leads to blindness. A DNA test exists for one form of PRA, so you can ask breeders for proof of clearance. For amyloidosis there is no test or cure mentioned in the sources we checked, so choosing a breeder who is open about family health history matters.

Amyloidosis

The GCCF lists hepatic (liver) amyloidosis, with a familial form described in the breed. Your Cat explains that protein deposits build up in organs, especially the liver, kidneys and pancreas, and can cause organ failure. The only definitive diagnosis is a tissue biopsy, and there is no effective cure, although diet and medication can support organ function and research is continuing. The Vet Desk adds that abnormal amyloid proteins can cause kidney failure, heart problems and blindness, and says incidence is higher in the Oriental than in other breeds.

What owners might notice

The sources we checked do not give a symptom list, so these are general signs of liver or kidney trouble in any cat, and not a diagnosis:

• Loss of appetite, weight loss or vomiting.
• Drinking and urinating more than usual.
• Yellow tinge to the gums or eyes (jaundice), lethargy or hiding.

Any of these needs a vet visit. Our guides to chronic kidney disease in cats and cat vomiting cover what to watch for.

What you can do

1. Ask the breeder about liver and kidney disease in parents, grandparents and siblings.
2. Keep up regular check-ups with blood and urine tests as your vet advises; see our yearly check-up guide.
3. Act early on changes in appetite, thirst or weight.
4. Follow veterinary advice on diet and medication if your cat is diagnosed; supportive care is the main approach according to Your Cat.

Progressive retinal atrophy (PRA)

The GCCF says PRA causes progressive blindness in the breed and that DNA tests are available, so buyers should ask breeders for clearance. The UC Davis Veterinary Genetics Laboratory describes one form, PRA rdAc, caused by a mutation in the CEP290 gene:

• Inheritance: autosomal recessive. A cat needs two copies of the mutation to lose its vision, and sex does not affect risk.
• Breeds: primarily Abyssinians, Somalis and some Ocicats, but the Oriental Shorthair and Oriental Longhair are among the breeds for which the test is appropriate.
• Onset: vision is normal at birth, degeneration is first detectable at about 7 months, and loss is slow and variable, with most cats blind by about 3 to 5 years of age.
• Treatment: none is available.

The Vet Desk notes that cats with PRA can be kept comfortable with regular veterinary care, and adapt to limited sight well in a stable home. Keep furniture and routines consistent so a cat with limited sight can find its way around.

Reading a PRA test result

• N/N (normal): no rdAc mutation; cannot pass it on.
• N/rdAc (carrier): not affected, but passes the variant to about half of its offspring. Carrier-to-carrier matings give about 25% affected kittens.
• rdAc/rdAc (affected): will go blind and passes the variant to all offspring.

This test covers rdAc only. Other forms of PRA exist in other breeds, so ask the breeder what tests were done and which breed-specific tests apply to your cat's lines.

Signs of vision loss

• Bumping into objects or hesitating in dim light.
• Wide, dilated pupils or an eye shine that looks different.
• Reluctance to jump, or a change in confidence in a familiar home.

Sudden blindness is an emergency; see our eye health guide for a list of urgent signs, which applies to any breed.

Other conditions the sources mention

The Vet Desk lists a wider range of problems seen in Oriental Shorthairs, which should be treated as possibilities rather than certainties:

• Heart: endocardial fibroelastosis and aortic stenosis.
• Respiratory: asthma and bronchial disease.
• Cancer: an increased risk of lymphoma.
• Digestive and other: megaesophagus, hyperesthesia syndrome and flat-chested kitten syndrome (also noted by the GCCF).
• Everyday issues: obesity and dental disease; see our Oriental dental guide and nutrition guide.

The source does not name tests for most of these, and says genetic predispositions cannot be changed, though sensible basic care may reduce risk.

Choosing a kitten wisely

1. Ask for written test results for PRA (and any other relevant tests).
2. Ask about liver disease and amyloidosis in the pedigree.
3. Ask how long the parents lived and what they died of.
4. See the mother and the home, and ask for a vet health check on the kitten.
5. Be wary of breeders who say the breed has "no health problems".

Quick checklist

• Know the two main inherited conditions: amyloidosis and PRA.
• Ask for PRA clearance and family health history.
• Keep up regular vet check-ups, and act early on changes.
• Keep your cat lean and its teeth clean.
• This is general information, not veterinary advice.

Keep reading

• The ultimate Oriental cat breed profile
• Dental care and hygiene basics for Oriental cats
• Chronic kidney disease in cats: signs and what to do
• Understanding PK deficiency and PRA in Somali cats
• Turkish Van health problems and genetics
• Common Norwegian Forest Cat health issues

Sources

• GCCF: Oriental breed profile
• Your Cat: Oriental cat breed profile
• UC Davis Veterinary Genetics Laboratory: PRA rdAc
• The Vet Desk: Oriental Shorthair cat health problems