Protein Deposits (Amyloidosis) in Cats

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Last updated on
4 min read

Key takeaways

Amyloidosis in cats is the accumulation of amyloid, a type of protein. Amyloidosis may occur throughout the body, with the kidneys being the most severely affected.

  • Causes of amyloidosis include plasma cell tumors, multiple myeloma, and chronic inflammatory conditions such as bacterial and parasitic infections, and autoimmune disorders
  • Symptoms of amyloidosis include weakness, lethargy, increased urination, increased thirst, and vomiting
  • Diagnostics focus on identifying the underlying cause and the location of protein deposits, and include tests such as physical examination, bloodwork, urinalysis, and tissue biopsy
  • Treatment depends on which organs are affected, but commonly involves IV fluids, nutritional support, kidney-protecting medications, and anticoagulant medications
  • Prognosis is poor in most cases, with many cats surviving less than a year after diagnosis
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A closer look: Protein Deposits (Amyloidosis) in Cats

Amyloidosis is a rare condition in cats. In this condition, improperly formed proteins (amyloids) build up in an area of the body causing systemic issues. The accumulation of proteins primarily affects the kidneys, and can rapidly lead to kidney failure. Cats showing symptoms of kidney failure require prompt veterinary attention to begin treatment and slow the progression of disease. Many cats with amyloidosis have a poor prognosis, and survive less than a year after diagnosis.

Risk factors

Siamese and Oriental shorthair cats are more prone to amyloidosis and are prone to developing liver fractures as a side effect of it.

Amyloidosis in other organs can cause additional symptoms.

Possible causes

Amyloids have an abnormal shape that cannot be broken down by the body, causing it to accumulate within the tissues. The main sources of amyloid are antibodies (primary amyloidosis) and inflammation (secondary amyloidosis). Secondary amyloidosis is the most common type in cats.

The main causes of primary amyloidosis are multiple myeloma and plasma cell tumors.

Some breeds of cat have inherited forms of amyloidosis, including Abyssinians, Siamese, and oriental shorthair cats.

Main symptoms

The symptoms of amyloidosis depend on the tissue affected. In most cases, the kidneys are the main site of amyloid accumulation.

Testing and diagnosis

Diagnosis of amyloidosis involves identifying the misshapen proteins in the tissue, and the underlying cause leading to amyloid accumulation. Diagnostic tests include:

  • Physical examination
  • Bloodwork
  • Urinalysis
  • Ultrasound of the abdomen
  • Kidney biopsy

Steps to Recovery

Treatment focuses on managing the underlying condition. In most cases, the kidneys are affected, so treatments include:

  • IV fluids
  • Nutritional support, including placing a feeding tube
  • Medications to protect the kidneys from further damage
  • Medications to reduce blood pressure
  • Anticoagulant medications

Cats with amyloidosis require regular follow-up appointments.

Amyloidosis is typically a progressive disease with no definitive cure. Many cats with kidney failure due to amyloidosis survive less than one year after diagnosis. Cats with amyloid deposition in other organs, such as the liver, have a grave prognosis due to a high risk of sudden, uncontrollable bleeding.


Some forms of amyloidosis have an inherited component, so removing affected animals from the breeding population is recommended for prevention. Other forms cannot be prevented, however routine check-ups by a veterinarian can help identify the signs of amyloidosis early, potentially leading to better outcomes.

Amyloidosis is not contagious.

Are Protein Deposits (Amyloidosis) in Cats common?

Amyloidosis is rare in cats.

Typical Treatment

  • IV fluids
  • Medications to protect the kidneys
  • Nutritional support
  • Medications to reduce blood pressure
  • Anticoagulant medications


Smith, F.W.K., Tilley, L.P., Sleeper, M.M., Brainard, B.M. - Writing for Blackwell’s Five-Minute Veterinary Consult: Canine and Feline. Seventh Edition.
Tammy Hunter; Robin Downing - Writing for VCA Animal Hospitals
Ian Rodney Tizard - Writing for Merck Veterinary Manual

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