Autoimmune Kidney Disease
The kidney is an organ that is quite sensitive to immune diseases. Any deposits of cells or proteins will interfere with the efficiency of its intricate filtering and reabsorption system. While some breeds such as Shih Tzu, Lhasa apsos, Doberman pinschers, soft-coated wheaten terriers, and Samoyeds may have genetic based renal disease, immune problems can strike any dog. (See Chapter 15 for more on genetic diseases.)
In glomerulonephritis, part of the kidney's filtration system (the glomerulus) is inflamed. This might be the result of a bacterial infection or even cancer, but it can also be caused by deposits of antigen and antibody from immune diseases. These immune deposits interfere with the kidneys' function of filtering out and resorbing protein. This problem is indicated by the presence of protein in the urine.
Amyloidosis is another type of kidney disease. In this case, the protein amyloid is deposited along the kidney's tubules. The amyloid interferes with the kidney function and leads to renal disease. This protein may get deposited in other tissues as well. Amyloidosis is most common in Shar-Peis. Dogs with the disease suffer from swollen, painful joints, cyclic fevers, and kidney disease. Blood work, urinalyses, and biopsies might be required to definitely diagnose amyloidosis. Dogs with this problem are treated with antiinflammatory drugs and immunosuppressives.
End-Stage Renal Disease
The kidneys are so efficient that symptoms of kidney problems can be hidden for a long time. More than 75 percent of the working tissue must be damaged before routine testing will show any sign of kidney disease and before your dog will show any clinical signs of illness. Dogs with end-stage renal disease (ERD) often have had a long course of chronic kidney problems. Blood tests, a thorough clinical history and urinalyses are important for diagnosing kidney disease. In some cases, your veterinarian may need to do a biopsy and/or an ultrasound exam.
New testing for end-stage renal disease (ERD) looks for tiny amounts of a protein called albumin in the urine. This test is extremely sensitive and may catch kidney failure early on, when intervention is most likely to succeed. Many veterinarians recommend screening middle-aged and senior dogs for kidney problems.
Signs of Kidney Failure
Dogs with kidney failure may drink large amounts of water and pass a large amount of diluted urine. They may also go to the opposite extreme and stop drinking much and therefore pass little urine. It is important to push fluid therapy for dogs with renal problems to stimulate urine production. If you can't encourage your dog to drink, your veterinarian may need to give subcutaneous fluids under the skin or use an intravenous catheter to push fluids directly into your dog's system.
Treating Kidney Problems
Along with fluids to flush out the kidney system, your dog may need antibiotics to fight infection, extra vitamins to make up for those lost in the fluid flush, and medications to encourage red blood cell production and to fight anemia. The kidney is an important source of erythropoietin, which stimulates red blood cell production. That's why secondary anemia is often a by-product of kidney damage. Dialysis is only available at a few veterinary schools and specialty practices. It is primarily used for acute renal crises, not long-term maintenance.
Some veterinary schools and specialty practices are working on kidney transplants for dogs with nonresponsive kidney failure. Rejection is a problem, just as it is in people, and families are required to adopt the donor dog — usually a healthy shelter dog.