Kidneys filter the body's waste, keeping toxins out of the bloodstream. A dog's kidneys may become compromised for a variety of reasons, such as kidney stones, trauma, toxic substances and damaged tissue. As kidneys fail, the dog is at risk for uremia, the build-up of toxins in the bloodstream.
Kidney Failure vs. Uremia
Barney doesn't have to experience a traumatic event to have a decline in his kidney power. Most cases of kidney failure in dogs are gradual in onset, taking months to develop and present symptoms. Generally, a dog who begins showing symptoms of kidney failure has lost about 75 percent of his kidney function. A dog in kidney failure tends to drink and urinate more. His kidneys can't process nitrogen, ammonia and other wastes so efficiently any longer, so they're retained in his bloodstream and tissues, leading to uremia.
A Slow Decline
The vet can gauge how much strain Barney's kidneys are under by measuring his blood urea nitrogen -- or BUN -- as well as his creatinine and electrolyte levels. The wastes circulating through his body affect the rest of his systems, including his nervous, digestive, immune, urinary, lymphatic, respiratory and musculoskeletal systems. As a result, you'll begin to see a different dog. He may not be interested in food and experience diarrhea and vomiting. He may lose interest in drinking as well, and merely stand around his food or water dish.
In the earlier phases of uremia, Barney will look normal, but may appear depressed or lethargic, as he's simply not feeling well. Eventually the visible symptoms of diarrhea and vomiting may appear, as well as a loss of appetite. His coat may become dry and his tongue can take a brownish color; his breath may smell a bit like ammonia. As uremia progresses, he may develop ulcers in his mouth and a fever, and his pulse can become abnormally rapid or slow. A dog in the end stages of kidney failure may have seizures or even fall into a coma.
Lightening His Kidney Load
If Barney's uremia is acute, the cause of his compromised kidneys will be addressed, as well as the effects of the uremia. His blood will have to be regularly monitored to gauge his BUN level. Blood test results and behavior will guide the vet's recommendations, including potentially adjusting his diet and giving Barney a phosphorus binder to take the strain off his kidneys. As well, ensuring your dog gets plenty of fresh water is critical, and if he's stopped drinking, fluid therapy may be used to keep him hydrated.