VETzInsight

Diabetic Ketoacidosis in Dogs and Cats

February 9, 2010 (published) | August 31, 2020 (revised)

Ketoacidosis is one of the most extreme complications of diabetes mellitus that can be experienced. Unfortunately, most cases of ketoacidosis are in patients that were not previously known to be diabetic so the owner (and pet) must deal with two serious diagnoses: one acutely life-threatening and expensive and the other requiring on-going commitment and daily treatment.

The diabetic patient has an insulin deficiency. To recap, there is a huge amount of glucose in the bloodstream but without insulin, none of it can get inside the cells that need it. It just circulates around uselessly. The tissues, some of which require glucose as their only food, are starving. Add to this some sort of second stressful condition such as infection or pancreatitis, and the tissue demand for food/fuel increases. The tissues, including the brain, become especially desperate and the body begins to frantically break down fat in order to liberate the small amount of carbohydrate (which can convert to glucose) contained therein.

Fat is able to convert to a biochemical called a ketone body. Ketone bodies can be used as an alternative fuel source by tissues that require glucose (brain, red blood cells etc.). This will save the day in the short term but the problem is that ketone bodies do not "burn clean." When ketone bodies are burned, pH and electrolyte imbalances ensue. These imbalances created dehydration, which in turn creates more pH and electrolyte imbalances. A metabolic disaster results if this state of glucose desperation persists.

Most patients in diabetic ketoacidosis are lethargic, depressed, and will not eat. They are dehydrated and frequently nauseated. Blood glucoses are extremely high and ketones can be detected in the urine. The goal is to gradually correct all the imbalances, get the patient out of the extreme fat-burning state, and establish some sort of initial regulation of the diabetes. 

Prognosis is generally fair as long as the complicating disease (the disease that is happening on top of the diabetes mellitus) can be resolved. That said, round-the-clock monitoring of electrolytes and blood sugars is needed to safely guide the patient through the crisis, and this kind of care has significant expense. Ketoacidosis involves potential disasters in potassium, phosphorus, pH, blood sugar, and sodium. All of these parameters must be controlled. The goal is to convert the complicated diabetic patient into an uncomplicated diabetic patient, but the patient will still be diabetic at the end of treatment.

What to Expect in the Hospital

The sooner the crisis is recognized, the faster treatment can be started. Because electrolytes can change moment by moment, blood testing is necessary throughout the day to keep track and keep the imbalances corrected. A facility that offers 24-hour care is ideal. Aside from the monitoring required to manage the ketoacidosis, testing to determine the precipitating stress is necessary as well.

In dogs, the most common precipitating/concurrent conditions are: pancreatitis, urinary tract infection, and Cushing's disease. In cats, precipitating/concurrent conditions include: hepatic lipidosis, kidney infection, pancreatitis, and cholangiohepatitis.

Intravenous Fluids

Fluid therapy is the key to treatment. The patient is invariably dehydrated from the high circulating blood sugar levels, which cause excess fluid loss in urine, as well as from vomiting and/or diarrhea, which are common in ketoacidosis. Aside from simply providing fluids, the IV fluid provides a vehicle by which other metabolic derangements can be repaired.

Insulin

Blood sugar must be controlled if treatment is to be successful but to prevent brain damage, blood sugar levels must be dropped slowly. To achieve this, “regular insulin” (typically Humulin R®) is used, given either as multiple intramuscular injections or as a continuous drip. This type of insulin is short acting and wears off quickly, which allows it to provide small adjustments. It is not until the patient is eating and nausea has been controlled that maintenance insulins can be started.

Potassium

Patients in ketoacidosis are greatly depleted in potassium. While insulin is needed to control blood sugar, insulin makes the problem worse by driving potassium into the body’s cells and out of the bloodstream. Typically, high amounts of potassium must be supplemented in the intravenous fluid solution.

Phosphorus

Low levels of phosphorus also accompany diabetic ketoacidosis and if levels drop too low, the patient’s red blood cells will begin to burst and be unable to maintain integrity. Phosphorus is also supplemented through the intravenous fluid solution.

Blood pH

The term ketoacidosis implies that the blood pH is overly acidic. If the situation is severe enough, sodium bicarbonate must be added to the intravenous therapy.

All these aspects require regular monitoring, which means lab work perhaps four times daily or more. Patients in diabetic ketoacidosis require close monitoring and intensive care.

When urine dipsticks no longer test positive for ketones and the patient is eating well and in good spirits, he or she is able to go home and be managed as a regular diabetic. Diet, monitoring, insulin etc. will be on-going concerns. Ideally, Ketostix, obtainable from any drug store, will be used at home to monitor for ketones to head off problems before they become extreme in the future.


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