Definition
- Functional or morphologic abnormalities resulting from heritable (genetic) or acquired disease processes affecting differentiation and growth of the developing kidney before or shortly after birth.
- Renal agenesis-complete absence of one or both kidneys.
- Renal dysplasia-disorganized renal parenchymal development.
- Renal ectopia-congenital malposition of one or both kidneys; ectopic kidneys may be fused.
- Glomerulopathy-glomerular disease of any type.
- Tubulointerstitial nephropathy-a non-inflammatory disorder of renal tubules and interstitium.
- Polycystic renal disease-formation of multiple, variable-sized cysts throughout the renal medulla and cortex.
- Renal telangiectasia-multifocal vascular malformations involving the kidneys and other organs.
- Renal amyloidosis-extracellular deposition of amyloid in glomerular capillaries, glomeruli, and interstitium.
- Nephroblastoma-a congenital renal neoplasm arising from the pluripotent metanephric blastema.
- Multifocal renal cystadenocarcinoma-a hereditary renal neoplasm in dogs.
- Fanconi syndrome-a generalized renal tubular functional anomaly characterized by impaired reabsorption of glucose, phosphate, electrolytes, amino acids, and uric acid.
- Primary renal glucosuria-an isolated functional defect in renal tubular reabsorption of glucose.
- Cystinuria-excessive urinary excretion of cystine because of an isolated functional defect in renal tubular reabsorption of cystine and other dibasic amino acids.
- Xanthinuria-excessive urinary excretion of xanthine caused by a deficiency in xanthine oxidase.
- Hyperuricuria-excessive urinary excretion of uric acid, sodium urate, or ammonium urate.
- Primary hyperoxaluria-intermittent hyperoxaluria, l-glyceric aciduria, oxalate nephropathy, and acute renal failure.
- Congenital nephrogenic diabetes insipidus-polyuria caused by diminished renal responsiveness to antidiuretic hormone.
Pathophysiology
- Many congenital and developmental renal disorders are caused by genetic abnormalities that disrupt the normal sequential and coordinated development and interaction of multiple embryonic tissues involved in formation of the mature kidney.
- Congenital and developmental renal disorders may also be caused by non-genetic factors affecting the developing kidney before or shortly after birth.
Systems Affected
Renal/Urologic
Genetics
- Familial renal disorders have been reported in the following breeds of dogs and cats:
- Renal agenesis in beagle and Doberman pinscher
- Renal dysplasia in Alaskan malamute, border terrier, boxer, chow chow, Dutch kookier, golden retriever, keeshond, Lhasa apso, miniature schnauzer, Rhodesian ridgeback, shih tzu, soft-coated Wheaten terrier, and standard poodle dogs
- Glomerulopathy in beagle, Belgian shepherd, Bernese mountain dog, Brittany spaniel, bull terrier, bullmastiff, Dalmatian, Doberman pinscher, English cocker spaniel, Newfoundland, Pembroke Welsh corgi, rottweiler, Samoyed, and soft-coated Wheaten terrier dogs
- Tubulointerstitial nephropathy in Norwegian elkhound dogs
- Polycystic renal disease in beagle, bull terrier, cairn terrier, and West Highland white terrier dogs, and in Persian, exotic shorthair, and Himalayan cats
- Renal telangiectasia in Pembroke Welsh corgi
- Renal amyloidosis in Abyssinian, Oriental shorthair, and Siamese cats, and in beagle, English foxhound, and shar-pei dogs
- Renal cystadenocarcinoma in German shepherds
- Fanconi syndrome in basenji and border terrier dogs
- Primary renal glucosuria in Norwegian elkhound, Scottish terrier, and basenji dogs
- Cystinuria in Australian cattle, Australian shepherd, basenji, basset hound, bullmastiff, Chihuahua, English bulldog, dachshund, French bulldog, Irish terrier, mastiff, Newfoundland, Scottish deer hound, Staffordshire bull terrier, and Welsh corgi dogs and in domestic cats
- Xanthinuria in Cavalier King Charles spaniel and wirehaired dachshund dogs, and in domestic shorthair cats
- Hyperuricuria in Dalmatians, black Russian terriers, and English bulldogs
- Primary hyperoxaluria in domestic shorthair cats and in Tibetan spaniels.
Incidence/Prevalence
Uncommonly recognized, but occur more frequently in related animals from more than one generation than in the general population.
Signalment
Species
Dog and cat
Breed Predilections
Sporadic cases can occur without an apparent familial predisposition in any breed of dog or cat.
Mean Age and Range
Most patients are <5 years old at time of diagnosis.
Predominant Sex
- Familial cystinuria occurs primarily in male dogs.
- Samoyed hereditary glomerulopathy more common in males than females.
- Familial glomerulonephropathy of Bernese mountain dogs is more common in females.
Signs
General Comments
Most congenital and developmental disorders cannot be distinguished from acquired renal diseases on the basis of history or physical examination.
Historical Findings
- Indicate chronic renal failure.
- Some glomerulopathies associated with abdominal distension, edema, or other signs of the nephrotic syndrome.
- Abdominal distension in some patients with polycystic kidneys or renal neoplasms.
- Hematuria or abdominal pain in some patients with renal telangiectasia or renal neoplasms.
- Patients with unilateral renal agenesis, ectopic kidneys, and isolated renal tubular transport defects are frequently asymptomatic.
Physical Examination Findings
- Signs associated with chronic renal failure.
- Ascites or pitting edema in some patients with protein-losing glomerulopathies or amyloidosis.
- Renomegaly or abdominal mass lesions in some patients with polycystic kidneys, renal neoplasms, or fused ectopic kidneys.
Causes
Non-hereditary
- Infectious agents-feline panleukopenia virus and canine herpesvirus infection associated with renal dysplasia.
- Drugs-corticosteroids, diphenylamine, and biphenyls associated with polycystic kidneys; chlorambucil and sodium arsenate associated with renal agenesis.
- Dietary factors-hypo- or hypervitaminosis A associated with renal ectopia.
