Causes of Nephrotic Syndrome in Dogs. Two common causes of nephrotic syndrome include: Glomerulonephritis (GN) This is an inflammation of the kidney – specifically in the area referred to as the glomerulus. Familial GN has been reported in the Bernese mountain dog, Samoyed, Doberman pinscher, cocker spaniel, Rottweiler, greyhound and wheaten terrier.