Renal Dysplasia, sometimes called juvenile renal dysplasia, is a developmental disease of the kidney. Portions of one or both kidneys fail to mature properly, reducing kidney function. In severe cases, where a significant portion of the kidneys are affected, the disease will begin early in life and is invariably fatal. Dogs with lesser amounts of abnormal tissue may not begin to exhibit signs of disease until adulthood. Depending on how much of each kidney is affected the disease may prove fatal or the dog may never show overt signs of kidney disease, though its diminished kidney function could contribute to diminished lifespan. Dogs with only one affected kidney (a very rare situation) may live a normal life without sign of disease.
The disease likely arises from a combination of genetic and environmental factors. Environmental factors have not been established but canine herpesvirus infection in the dam or toxic exposure during gestation as well as infection or trauma of fetal tissue have been proposed. Symptoms vary widely and can include excessive drinking or urination, lethargy, anorexia, vomiting, diarrhea, ulcers, pale gums, weakness, stunted grown, poor condition, dry coat, weight loss, or abnormal heat cycles in females. Some dogs experience significant bone pain.
A probable diagnosis of RD can be reached through veterinary exam plus blood and urine tests but the only way to confirm the presence of the disease is with a kidney biopsy. Treatment is primarily through dietary modification and possibly dietary supplements specific to improving kidney function. In some cases medication may be needed. RD dogs need unlimited access to clean, fresh water; severely ill dogs may require intravenous or subcutaneous (under the skin) fluids. Kidney dialysis and transplant are possible but require very specialized clinical care and are costly.
Even though environment plays a role, RD is inherited. Affected dogs should not be bred. If the disease arises after semen has been stored from males, it should be discarded. Relatives should be bred to mates without family history of RD.