Overview of Renal Amyloidosis in Cats
Kidney amyloidosis is a rare disorder of protein metabolism in which abnormal deposits of protein called amyloid is deposited in the kidneys. The cause of kidney amyloidosis remains poorly understood. It is a hereditary condition in certain breeds of cat. It also may occur in other breeds or mixed breeds as a reaction to chronic infections and inflammatory conditions. The term renal and kidney mean the same thing and may be used interchangeably.
Below is an overview of Feline Amyloidosis followed by in-depth information on the diagnosis and treatment of this condition.
Most cats with kidney amyloidosis are old at the time of diagnosis (7 years in cats). The disease can occur in any age or breed. It is a hereditary disorder in Abyssinian cats. There is a definite female predilection in Abyssinian cats (females are 1.6 times as likely to be affected compared to males).
Amyloid deposits in the kidney lead to excessive protein loss in the urine and eventual chronic kidney failure. Amyloid may also be deposited in other organs like the liver, spleen and pancreas, causing them to malfunction as well.
What to Watch For
Diagnosis of Renal Amyloidosis in Cats
Treatment of Renal Amyloidosis in Cats
Home Care and Prevention
Manage any concurrent kidney failure as described by the veterinarian with prescription diets, subcutaneous fluids, hormonal therapy to correct anemia and vitamin D therapy. Control hypertension with medication if necessary and minimize risk of thromboembolism (forming blood clots) using low dose aspirin, if prescribed.
There are no specific preventative measures against amyloidosis.
In-depth Information on Renal (Kidney) Amyloidosis in Cats
Kidney amyloidosis is an uncommon disorder of protein metabolism in which a protein called amyloid is abnormally deposited in the kidneys, causing excessive protein loss in the urine.
Kidney amyloidosis is uncommon in cats, except for Abyssinian cats, in which it is familial. Chronic inflammatory diseases can predispose cats to the development of kidney amyloidosis, however only a small percentage of cats with chronic inflammatory conditions develop amyloidosis, thus, other factors must also be important in the development of amyloidosis. These other factors are poorly understood. Most cats with amyloidosis do not have discernible inflammatory or infectious conditions at the time of diagnosis.
Most cats with kidney amyloidosis are old at the time they are diagnosed with the disease. The average age is 7 years. The hereditary form tends to strike earlier; Abyssinian cats are less than 5 years of age on average, at the time of death or euthanasia from the disease.
Amyloid deposits in the kidneys lead to eventual kidney failure. Signs of kidney failure include anorexia, lethargy, and weight loss. Excessive water consumption and urination is another common sign of kidney failure. Occasional vomiting is also seen.
Kidney amyloidosis causes excessive protein loss in the urine. One of the proteins lost in the urine is a protein responsible for preventing the blood from clotting. As a result, affected cats are more susceptible to formation of blood clots. These clots tend to lodge in the lungs, causing clinical signs that may not be obvious, ranging from labored breathing to major respiratory distress.
Excessive urinary loss of a protein called albumin may lead to ascites, which is an accumulation of fluid in the abdomen. It may also lead to edema, which is a swelling of the limbs and/or face. Ascites and edema are relatively uncommon occurrences in cats with kidney amyloidosis.
Treatment of kidney amyloidosis is difficult and often unrewarding, especially if kidney failure has already begun to develop. The principles of therapy are as follows:
Colchicine may be beneficial for humans with the disorder in certain circumstances, but it has yet to be studied well in cats.
Follow-up Care for Cats with Amyloidosis
Optimal treatment for your catrequires a combination of home and professional veterinary care. Follow-up can be critical, especially if your cat does not rapidly improve.