The purpose of peritoneal dialysis in dogs is to assist the failing function of the kidneys by filtering waste products from the blood. In general, peritoneal dialysis is only used in dogs with acute renal failure or end-stage kidney disease when there are no other effective treatment options left. Because peritoneal dialysis is sometimes the last option for dog owners, it is important to understand how the procedure works and why it is beneficial.
Understanding Kidney Function in Dogs
In dogs, the kidneys function as filters. Everything that a dog eats goes through the digestive tract where it is metabolized and eventually filtered into either urine or feces. The kidneys break down things like salt and protein, savoring only what is essential to live, and then convert these byproducts into urine. When the kidneys fail to function properly, these byproducts have no place left to go except into the bloodstream. Once they reach the bloodstream, they build up to unsafe levels and essentially become toxic to the dog. This is why proper kidney function is essential to the life of a dog.
Peritoneal Dialysis
Dialysis is the process in which catheter is used to circulate normal saline through the dog’s body so that the toxins in the bloodstream can be pushed out and converted to urine, essentially taking the place of kidney function temporarily. Peritoneal dialysis in dogs is done by using the membranous layer of the abdomen, also known as the peritoneum. When used in conjunction with an IV filter, this membrane acts as a waste filter which clears toxins and excessive fluid from the dog’s body. With this procedure, the stress placed on the kidneys to work harder to obtain normal kidney function is relieved; and electrolyte balance can then be restored.
Peritoneal dialysis is typically completed in 3 stages. First, the catheter is inserted into the peritoneum, and fluid is pushed into the peritoneal cavity. Next, fluid and waste in the dog’s bloodstream travel across the membranous layer of the peritoneum and mix with the dialysis fluid. Lastly, the fluid received during dialysis is drained through the peritoneum. This procedure is actually a type of medical intervention intended to mimic exactly what the kidneys would do under normal circumstances.
Side Effects and Outcomes of a Peritoneal Dialysis
Peritoneal dialysis is the most commonly used type of dialysis in dogs. Again, the purpose is to relieve the dog of dangerous toxins and return the electrolyte balance to normal. However, peritoneal dialysis can sometimes cause increased levels of magnesium and albumin; so it is important to be in constant contact with your veterinarian during the procedure.
The side effects of this procedure can include abdominal fluid retention, leakage from the catheter site, swelling in the limbs, and sometimes behavioral changes or irritability. In general, however, the benefits of peritoneal dialysis in dogs far outweigh the possible side effects.
Peritoneal dialysis in dogs generally takes between 4 and 6 hours to complete, and it is not considered to be as effective as hemodialysis. However, because of the extreme cost of hemodialysis equipment and the fact that most veterinarians are not set up with this type of equipment, peritoneal dialysis is usually considered the only option for dogs with end-stage renal disease.