What is ... ?:

Several breeds of dogs are known to be affected by a wide range of kidney diseases that are proven or suspected to be inherited. In many of these disorders, the kidneys are apparently normal at birth but begin to deteriorate early in life (less than 1 year of age). While the underlying problem in the kidneys varies between breeds, the end result is the same - kidney failure for the dog, generally by 5 years of age, although the severity and rate of progression vary between breeds and between individual dogs.

For many of these disorders, the mode of inheritance is not known. The term "hereditary" is used when the inheritance is known, and "familial" when the mode of inheritance is not known but the disorder occurs more commonly in related dogs than would be expected by chance. Where the actual defect in the kidney has been identified, a more specific name (given below) may be used. More than one name may be used for a particular disorder (see Related Terms below).

Breed	Disorder	Inheritance (if known)	(for veterinarian)
Bernese mountain dog	familial glomerulonephritis	thought to be autosomal recessive	membranoproliferative glomerulonephritis; immune-mediated
Bull terrier	hereditary nephritis	autosomal dominant	defect is in the structure of the glomerular basement membrane
Doberman pinscher	familial glomerulonephropathy	unknown	irregularities in glomerular basement membrane
English cocker spaniel	hereditary nephritis	autosomal recessive	abnormality in glomerular basement membrane
Golden retriever	renal dysplasia	thought to be autosomal recessive	abnormal differentiation of kidneys
Lhasa apso, shih tzu	renal dysplasia	thought to be autosomal recessive	abnormal differentiation of kidney tissue
Norwegian elkhound	familial nephropathy	unknown	tubulo-interstitial nephropathy
Pembroke Welsh corgi	renal telangiectasia	unknown	multiple dilated renal blood vessels
Samoyed	hereditary nephritis	X-linked dominant	abnormality in glomerular basement membrane
Schnauzer, miniature	juvenile nephropathy	unknown	glomerular and tubular lesions
Shar pei, Chinese	renal amyloidosis	unknown, possibly autosomal recessive	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
Rottweiler	renal dysplasia	unknown	abnormal differentiation of kidney tissue
Soft-coated wheaten terrier	renal dysplasia	thought to be autosomal recessive	abnormal differentiation of kidney tissue
Soft-coated wheaten terrier	see protein-losing enteropathy and nephropathy	unknown, familial	onset 6 years plus; chronic glomerulonephritis/glomerulosclerosis

Familial kidney disease has also been reported in the English foxhound (renal amyloidosis), Belgian shepherd (Malinois) (glomerulocystic disease), bull mastiff (glomerulonephropathy), and Rhodesian ridgeback, border terrier and Dutch kooiker (all renal dysplasia).

What breeds are affected by ... ?:

What does ... mean to your dog & you?:

The signs of kidney failure are the same in young animals as in older dogs. One of the earliest signs you may notice is that your dog drinks more and urinates more. (Sometimes in young pups, owners may not recognize excessive urination as such, but think it is due to the dog being slow to housetrain.) As more and more kidney function is lost, other signs develop including poor appetite, loss of weight, lethargy, vomiting, and pale gums due to anemia. Although the progression may be slowed by treatment, kidney failure is ultimately fatal.

For most of these disorders, dogs show signs of kidney dysfunction before 1 year of age, and their kidneys fail before 5 years of age. In pups affected at a very young age (less than 5 or 6 months), growth may be noticeably stunted. Polycystic kidney disease in bull terriers is an exception. Affected animals often show no signs until 2 years of age or more, and may not develop kidney failure until 8 years. In Doberman pinschers and Norwegian elkhounds, signs of kidney failure may also appear later in life (6 years of age). In the samoyed, because inheritance is sex-linked, males are more severely affected. Male pups with hereditary glomerulonephropathy usually show signs by 2 to 3 months of age, and kidney function deteriorates rapidly, resulting in death by an early age (approximately 1 year). Although affected females still show some kidney dysfunction, it is less severe and does not progress to kidney failure. Even if only mildly affected, they are carriers of the disorder and should not be bred. In Chinese shar-pei dogs affected with amyloidosis, amyloid (a type of protein) is deposited in the kidneys and other organs. Most of the time, the clinical signs you see relate to disruption of kidney function which eventually (by about 3 to 5 years of age) leads to kidney failure. Affected dogs may have intermittent fever and swelling and pain in their joints, especially the hocks. Pembroke Welsh corgis with renal telangiectasia have episodes of blood in the urine as adults.

How is ... diagnosed?:

The signs described above can have several causes, including other inherited disorders such as a heart or liver defect. Your veterinarian will do blood and urine tests that will point to your dog's kidneys as the cause of the problem.

FOR THE VETERINARIAN
Typical signs of CRF include azotemia, hyperphosphatemia, isosthenuria, and nonregenerative anemia. Calcium concentrations are variable. Persistent proteinuria is highly suggestive of hereditary nephritis, even before any clinical signs are evident. Proteinuria is not a consistent sign in renal dysplasia.

In suspect bull terriers, repeated protein/creatinine ratios 0.3 provide supportive evidence for hereditary nephritis in dogs that are older than 2 years of age, but who show no overt signs of renal failure. This provides important information in decisions about breeding. Male samoyeds with hereditary glomerulonephropathy develop proteinuria, glucosuria and isosthenuria by 2 to 3 months of age, and azotemia and overt renal failure by 6 to 9 months. Affected females (carriers) develop proteinuria at a young age but may never progress to renal failure. In cocker spaniels with familial nephropathy, proteinuria is usually present by 4 to 6 months of age and is persistent and marked. This is followed by decreased growth, and the development of isosthenuria and azotemia.

There are 2 different familial renal syndromes in the soft-coated wheaten terrier- renal dysplasia (onset usually before 2 years of age) and protein-losing enteropathy and nephropathy (onset 2 to 11 years of age). In Chinese shar pei dogs with renal amyloidosis, proteinuria is usually marked, although it may be mild or absent in dogs with renal medullary, but not glomerular, amyloidosis.

VetGen has DNA testing available for kidney disease in some breeds.

How is ... treated?:

There is no cure, but there are ways to slow the progression of kidney disease, which your veterinarian will discuss with you. These include making sure your dog always has access to fresh drinking water, feeding a special (high quality, low-protein) diet, and the use of some medications which help to support kidney function. Your veterinarian will help you to recognize the signs that your dog's kidneys have deteriorated to the point where euthanasia becomes the best option.

FOR THE VETERINARIAN
Patients should be managed (including regular monitoring)as for other animals with chronic renal failure. The goals are to maintain normal hydration and electrolytes, delay the progression of renal failure and its complications, address signs of uremia (eg.vomiting), and minimize proteinuria.

Breeding advice:

Affected animals should not be bred, and neither should their parents. Any related animal being considered for breeding should be screened for protein in the urine, which is an early sign of kidney disease. All bull terriers being considered for breeding should be screened by measuring protein/creatinine ratios ( a simple test requiring a blood and a urine sample). Ratios greater than 0.3 on 2 occasions more than a month apart, indicate potential hereditary nephritis. Kidney function in these dogs should be monitored, and they should not be used for breeding.

FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.

Resources:

Dalby AM. Glomerulonephritis. In: Côté E, ed. Clinical Veterinary Advisor Dogs and Cats. Missouri: Mosby Elsevier, 2007:442-444.
DiBartola, S. 1998. Renal amyloidosis. ACVIM-Proceedings of the 16th Annual Veterinary Medical Forum. p. 23-24.
Gleadhill, A. 1997. Juvenile nephropathies in dogs and cats. In Practice. Vol 19(5):270-277.
Mordecai A, Sellon RK. In: Côté E, ed. Clinical Veterinary Advisor Dogs and Cats. Missouri: Mosby Elsevier, 2007:953-954.
Sargan DR. (Search for renal disease by name, as above). In IDID - Inherited diseases in dogs:web-based information for canine inherited disease genetics. 2002-2011.