Anatomy and Function of the Kidneys

The kidneys play a vital role in the health and well being of all dogs. Kidney failure has been cited as the second most likely cause of natural death in dogs and cats. This fact alone makes the information on how the kidneys work and what their prime function is in the normal course of your dog's life extremely important.

The kidneys have several functions such as eliminating waste products from the body, regulating the level of water in and outside of the cells within the body by concentrating or diluting the urine output and producing hormones which help the bone marrow to grow red blood cells. The kidneys help control blood pressure, maintain the proper balance and removal of calcium and phosphorus.

The basic unit within the kidney, which acts as a filtration device is called the nephrons. Kidney failure occurs when three- fourths of the nephrons of both kidneys are damaged or unable to function. The most common causes of kidney damage include immune-mediated diseases, kidney infections, kidney stones and congenital diseases. The main problem for the nephrons is any damage can cause irreversible changes and, therefore, function cannot be restored.

Another function of the kidneys is to regulate the volume of extra-cellular fluid in order to maintain a stable internal environment for cells. This is accomplished by regulation of water, electrolytes and calcium and phosphorus production. The fluid that remains is urine, which is collected in a central area of the kidney and funneled into a small tube called the ureter. The ureters (one from each kidney) run from the kidney to the bladder, which is located just in front of the pubic bone of the pelvis.

Causes of kidney disease
Click a link below to jump to more detailed information on that topic.

Types and Descriptions of Kidney Disease

Polycystic Kidney Disease
(PKD) is not very common and creates cystic areas in the kidneys where normal function and structure are lost.

Familial Glomerulonephritis
Patients present heavy proteinuria, often with microhematuria, hypertension and with normal or slightly depressed renal function. This is an autosomal dominant disease.

Hereditary Nephritis
Defect is in the structure of the glomerular basement membrane

Renal Agenesis
Also called kidney aplasia, occasionally occurs and the individual is born with one or both kidneys not present. Dogs, cats and humans can survive quite well if one normal kidney is present and functioning.

Renal Hypoplasia
A condition where the kidney(s) do not develop completely.

Renal Cortical Hypoplasia
A condition where the cortex of the kidney develops incompletely

Renal Dysplasia
Abnormal differentiation of kidney tissue.

Renal Tubular Dysfunction
Occurs when the filtering tubules of the kidneys do not function properly. In Basenjis, glycosuria develops and is called Fanconi syndrome familial glomerulonephritis in the Bernese Mountain dog.

Hereditary Nephritis
Abnormality in glomerular basement membrane.

Renal Amyloidosis
Amyloid deposition most disruptive in kidneys; other organs (spleen, liver, pancreas) can be affected but with minimal clinical signs; may also have intermittent fever and joint swelling.

Polycystic Kidney Disease
Kidney tissue is gradually replaced by fluid-filled cysts.

Protein-losing Enteropathy and Nephropathy
Excessive loss of plasma and proteins into the gastrointestinal (GI) tract is called protein-losing enteropathy. It can result from any condition that damages the lining of the GI tract. The latter condition is thought to be related to adverse food reactions, and there is also loss of protein from the kidney (see also Familial Renal Disease).

Familial Glomerulonephropathy
Irregularities in glomerular basement membrane.

Renal Telangiectasia
Multiple dilated renal blood vessels.

Share Your Information with the Bedlington Terrier Health & Wellness Committee

In the Bedlington community, we are getting anecdotal and disjointed information about kidney issues. While the incidence of kidney disease was low in the BTCA Health Survey of 2003-2004, we are hearing enough anecdotal stories to warrant watching this, arming you with information, and gathering factual information.

If you have any kidney disease, it might help us improve the breed if you would please make the information available to one of the Health & Wellness committee members. We will track this and add all information we receive into a database. If sufficient information is available to warrant a research effort by a qualified researcher, we will pursue starting something. Until then, we will accumulate data and periodically review it to see if there is sufficient data for us to investigate with a research effort. In the meantime, thank you very much for your cooperation.

Treatment for Kidney Disease

Given the long list of different kidney diseases, covering possible treatment was beyond the scope of this article. However, there is excellent information available from the referenced web sites below. If you have specific questions about treatment that you believe would benefit the larger Bedlington community, please send them to:

Marci Berman

and the Health & Wellness Committee will consider addressing it.