I have a Siamese cat and was just reading about health problems this breed can encounter. One disease that was mentioned was amyloidosis. What is this disease and how likely is it that my cat might get this disease?Amyloidosis occurs when proteins called “amyloid” are deposited outside of cells in various tissues and organs, causing tissue and organ dysfunction. It is a rare condition in cats, although it is seen in Abyssinians. While certain family lines of Siamese cats are identified as predisposed, there is no clear genetic profile in the affected cats. The majority of cats diagnosed with amyloidosis are older than 7 years of age, although the age range at diagnosis can be from 1 to 17 years of age. It appears that the risk of developing amyloidosis increases with age. Certain Siamese cats with familial amyloidosis may be diagnosed as early as 1 – 4 years of age.
What are the symptoms of amyloidosis?The symptoms of amyloidosis vary depending on the organ system that is affected, and kidney involvement is most common. The affected cat may lose their appetite, become lethargic, have increased drinking and urinating, experience weight loss, vomiting, and diarrhea. In some cases, fluid will build up under the skin, in the abdomen, and/or in the chest cavity.
If the kidneys are involved and amyloidosis progresses, the cat may develop signs specific to kidney failure including:
● Mouth ulcers● Extreme weight loss● Ongoing vomiting● Dehydration
Some affected cats will develop blood clots in their blood vessels, and depending upon the location, there may be clinical signs. The cats may develop difficulty breathing or weakness in one or both rear legs.
What causes amyloidosis?Chronic infection, chronic inflammation, and certain types of cancer have been implicated in amyloidosis. There must be a familial predisposition for amyloid to be deposited in the tissues.
Is there any treatment for amyloidosis?If the cat with amyloidosis develops kidney failure, hospitalization with IV fluids may provide a way to stabilize the condition. Once stabilized, the cat may be able to tolerate outpatient management focused on kidney support with proper nutrition and any necessary medications. Some cats with amyloidosis also develop hypertension that should be treated. Any underlying condition like cancer, infection, or inflammation should be treated if possible.
Ongoing monitoring of organ system function, fluid balance, and blood pressure will be important in cats with amyloidosis. Any emerging symptoms can then be treated as soon as they are identified. Amyloidosis is a devastating disease, and if the kidneys are affected, the prognosis varies from 3 – 20 months. Cats who are mildly affected may have a nearly normal life expectancy.

This client information sheet is based on material written by Robin Downing, DVM, DAAPM, DACVSMR, CVPP, CRPP© Copyright 2016 LifeLearn Inc. Used and/or modified with permission under license.