Nephritis is the inflammation of the kidneys. There are several types of nephritis found in dogs: pyelonephritis, interstitial nephritis, hereditary nephritis.
Hereditary nephritis is hereditary non inflammatory disease of the renal glomeruli present in some breeds, like: Bernese mountain dog, Bull Terrier, Samoyed, and English Cocker Spaniel. While the severity of problems and rate of progression varies between breeds and between individual dogs, the end result is the same-kidney failure for the dog, generally by 5 years of age.
Pyelonephritis is an inflammation of the kidneys, usually caused by bacteria in the urinary tract, which had spread into the kidneys. The risk factors are anything that interferes with normal urine flow through the urinary system (in example stones in the kidneys or ureters), ectopic ureters in young dogs. Most prone to the pyelonephritis are very young and very old, those that have weak immune systems, and those with kidneys that cannot properly balance the amount of water in the urine. The failure of the kidneys might be sudden. Dogs with long-term pyelonephritis may have few or no signs, until the kidney failure begins. Dogs with pyelonephritis are at high risk for repeated infections. Animals with short-term pyelonephritis may be able to recover full kidney function, depending on the amount of damage that occurred before treatment.
Signs of pyelonephritis:
Pain in the sides, in the area around the kidneys
General sense of illness
Diagnosis of pyelonephritis is made through urine and blood samples. In many cases, ultrasonography or contrast x-rays may be necessary.
Interstitial nephritis is inflammation of the kidney. The sudden onset of acute interstitial nephritis is often triggered by infectious diseases. The most common cause is leptospirosis (Leptospira interrogans), which is usually spread by small wildlife and rodents, but also can occur in dogs living everywhere. Leptospirosis is zoonotic and might also affect humans.
Acute and Chronic Kidney Failure
Acute kidney failure is an abrupt decline in function that occurs over a period of days. Dogs can develop acute kidney failure as a result of toxin ingestion, decreased blood flow or oxygen delivery to the kidneys, infections and urinary obstruction.
Chronic kidney disease reveals itself over a period of time and its causes are often hard to determine. This condition develops slowly and affects mostly older dogs. As the disease develops at earlier stages it may have few or no signs and is difficult to be noticed. It is often caused by underlying illness and congenital and hereditary conditions, but a main cause of chronic kidney failure in dogs appears to be dental diseases.
Signs of Kidney Failure in Dogs:
Depression and listlessness
Loss of appetite/or decreased appetite
Blood in urine
Breathe odor (like ammonia)
Diagnostics of Kidney Failure in Dogs:
A complete blood profile, including a chemical blood profile, a complete blood count, and a urinalysis should be done to determine the disease. Dogs with chronic renal failure may have anemia, abnormal electrolyte levels, and elevated blood pressure. The levels of certain protein enzymes and chemicals such as creatinine and blood urea nitrogen (BUN) will also be high. X-ray or ultrasound imaging may also be used to observe the size and shape of the dog's kidney(s) to see if there are any visibly noticeable abnormalities, chronic renal failure causes kidneys to become abnormally small.