The goals of treating acute renal failure (ARF) are to alleviate the symptoms of circulating toxic waste build-up, correct electrolyte abnormalities, eliminate dehydration, restore normal urine production and concentration, delay progression of disease and improve the dog’s overall quality of life.
Treatment Options for Acute Renal Failure
It is critical to flush circulating toxic waste products from the blood of dogs in acute renal failure. Free access to fresh water is essential for dogs in renal failure. They must be able to drink enough water to compensate for their increased urine output, or they will develop life-threatening dehydration. Unfortunately, most decompensated animals will not voluntarily drink enough water to accomplish this. Dogs that are dehydrated, anorexic and vomiting usually need to be hospitalized so that they can start immediate, aggressive intravenous fluid and electrolyte replacement therapy to try and force toxins into the urine. After fluid and electrolyte balances are corrected, fluids can be given under the skin (subcutaneously), rather than directly into a vein. Many owners can do this stage of treatment at home.
If an ingested poison such as antifreeze is suspected as the cause of the crisis, activated charcoal or other substances may be given to bind the toxic material and speed its elimination through vomiting or in urine or feces.
Dietary changes can be helpful when they are customized to the individual dog. Dogs that are vomiting often are kept off food for a few days and may need to get their calories through a liquid diet using a feeding tube. Protein is poorly metabolized by dogs in renal failure, and phosphorus and sodium tend to accumulate in their blood. Most commercial kidney diets have less protein, phosphorus and sodium than maintenance diets. Some dogs resist sudden dietary changes, especially when they aren’t feeling well. When a sick dog refuses to eat and starts dropping weight, it becomes increasingly difficult for his body to fight disease. It can become more important for a dog with ARF to get enough calories than it is for him to eat a perfectly balanced diet. Tasty, calorie-packed meals may be the best choice, at least in the short term. A number of medications are available to decrease stomach acidity, reduce nausea, decrease stomach acidity and soothe sore gums, if vomiting and oral or gastric ulcers are involved.
Drugs that are metabolized by the kidneys or are known to cause kidney damage should not be used in ARF patients unless absolutely necessary. If leptospirosis is the cause of acute kidney failure, intravenous and oral medications are available to resolve the infection. Blood pressure irregularities may be manageable with medication.
Kidney transplants are gradually becoming available at a handful of veterinary teaching hospitals and referral centers for dogs with renal failure. Kidney dialysis is another potential therapy, although it is extremely expensive and rarely used in veterinary medicine. Dialysis involves routing the dog’s blood through special catheters into a machine that performs the filtering functions of normal kidneys. The procedure lasts 3 to 4 hours and must be done several times a week. Dialysis is slowly becoming available at a limited number of highly specialized veterinary facilities for short-term management of dogs with ARF.
The outlook for dogs with ARF is hard to predict. Dogs with infectious or obstructive causes tend to have a slightly better prognosis than those with toxic causes. Life expectancy can range from days to years, depending on the stage of disease at the time of diagnosis. Unfortunately, the prognosis for any affected dog is unfavorable. If management attempts are unsuccessful, euthanasia may be the only humane option.