Veterinarian Explains! What is Feline Amyloidosis? Symptoms, Diagnosis, Treatment, and Prevention

Have you ever heard the term "amyloidosis"? Amyloidosis is caused by the deposition of a protein called amyloid in organs such as the kidneys. This article will explain feline amyloidosis in detail.

What is Feline Amyloidosis? A Veterinarian Explains the Characteristics of the Disease

Basic Information and Causes of Amyloidosis

Amyloid is a type of protein, but it is also an abnormal fibrous protein produced by various systemic diseases such as infection, inflammation, and tumors. When the immune system reacts to systemic diseases, amyloid is produced and deposited between organ cells, leading to organ dysfunction. This condition is called amyloidosis. Amyloid can be deposited anywhere in the body, but it is known to be particularly prone to depositing in the kidneys and liver. Although amyloidosis itself is a relatively rare disease, no established treatment or prevention methods exist. In recent years, hepatic amyloidosis is said to be on the rise.

Which Cats Are at High Risk? Trends in Age and Breed

Amyloidosis is believed to have a genetic component. Abyssinian and Siamese cats are considered predisposed breeds, but any breed can develop the condition. Abyssinian cats, in particular, have a genetically altered amyloid structure and are said to have a high incidence of renal amyloidosis.

Amyloidosis often develops around 7 years of age, but in Abyssinian cats, it can occur before 1 year of age.

Symptoms of Feline Amyloidosis

Symptoms of Amyloidosis

Amyloidosis is a disease where amyloid deposits in organs, leading to organ dysfunction. It tends to deposit in organs throughout the body, but is especially common in the kidneys and liver. The kidneys and liver are called "silent organs," and symptoms do not appear until the disease has progressed significantly. Therefore, it is quite difficult to detect the disease in its early stages.

Caution is needed if you observe any of the following symptoms:

• Lethargy, loss of appetite
• Weight loss
• Increased urination
• Swelling of the body, or only the abdomen is distended
• Vomiting or diarrhea
• Yellow eyes or skin (jaundice)
• Tendency to bleed easily

Symptoms vary depending on the affected organ, but with renal amyloidosis and hepatic amyloidosis, these symptoms warrant attention.

If the condition worsens, protein loss can lead to low blood pressure and anemia. In cases of hepatic amyloidosis, the liver becomes fragile and may rupture.

Differentiation from Other Diseases

Amyloidosis is diagnosed by tissue biopsy, a test that involves taking a sample of an organ. Therefore, it is a very difficult disease to diagnose from blood tests or imaging tests. For this reason, it is often diagnosed as kidney disease or liver disease.

Diagnosis of Amyloidosis: The Examination Process by a Veterinarian

Blood Tests and Ultrasound Examinations

Blood tests reflect the overall condition, but it is difficult to detect abnormalities in the early stages. In the kidneys, especially, abnormalities in blood tests only appear when 75% of kidney function has deteriorated. Evaluation will include protein levels, platelet count, anemia, jaundice, liver function, and kidney function.

Ultrasound examinations can provide a more precise examination of abdominal organs. It can check the structure and size of organs such as the liver and kidneys, and confirm the presence of ascites.

Organ Tissue Biopsy: Its Importance and Cost

Amyloidosis can only be definitively diagnosed through a tissue biopsy. A fine needle aspirate (cytology), which involves inserting a needle into an organ, cannot provide a definitive diagnosis. Therefore, a portion of the organ is surgically removed through open surgery. Tissues affected by amyloidosis are fragile, and there is a risk of severe bleeding during removal. For this reason, it is advisable to perform this procedure in a secondary hospital equipped to handle major hemorrhages. Since this is an open surgery, there will be costs for anesthesia, surgery, pathological examination, and hospitalization. It is an expensive test that can cost over ¥100,000.

Treatment and Management of Amyloidosis

Medical Treatment and Palliative Care Options

Unfortunately, there is no cure for amyloidosis, and the deposited amyloid cannot be removed. Since the cause is systemic inflammation, treatment involves addressing the underlying cause and providing symptomatic relief.

If edema or ascites is observed, diuretics may be used. If a large amount of ascites accumulates, it can cause respiratory distress, so the ascites may be drained. In renal amyloidosis, symptoms of chronic kidney disease occur, so subcutaneous fluid therapy and antihypertensive drugs are used. In hepatic amyloidosis, coagulation abnormalities that impair hemostasis can occur, so vitamin K may be used, or hepatoprotective agents may be administered to protect the liver.

Because edema occurs, a low-sodium diet is necessary. Protein restriction is required if kidney function is significantly impaired.

Management Methods for Prognostic Improvement from a Veterinarian's Perspective

Amyloidosis cannot be cured, and long-term survival is not expected. Therefore, alleviating symptoms and improving quality of life are crucial. Amyloidosis is caused by systemic inflammation. It can develop if there is stomatitis, infection, or tumors. While tumor prevention is not possible, it is important to perform regular vaccinations, deworming, and oral care to eliminate inflammation. Additionally, if diagnosed with amyloidosis, it is necessary to switch to a diet with restricted salt.

Currently, there is no way to prevent amyloidosis, and it is a difficult disease to diagnose definitively. Therefore, it is important to prevent diseases that cause inflammation, maintain oral hygiene, and provide an appropriate diet. Also, early detection is generally not possible, so seek veterinary attention as soon as you notice any changes in your cat's condition.

Things to Be Mindful of in Daily Life with an Affected Cat

Stress is considered a factor that worsens amyloidosis. Take care to minimize stress and ensure your cat maintains as much calm as possible. Organs affected by amyloidosis are fragile, and especially in hepatic amyloidosis, bumping the abdomen can cause liver rupture and massive internal bleeding, which can be life-threatening. Therefore, physical activity should be limited as much as possible.

Summary

Amyloidosis is a disease where amyloid deposits in organs due to systemic inflammation, leading to organ dysfunction. While Abyssinian and Siamese cats are genetically predisposed, any cat with systemic inflammation can develop the condition. Since there is no cure, symptomatic treatment is the main approach.

Furthermore, there are no preventive measures, early detection is difficult, and a definitive diagnosis is often not achieved. If your cat develops any illness, seek treatment promptly to prevent ongoing inflammation. If amyloidosis is diagnosed, manage the condition through diet and medication, and encourage as much rest as possible.