Diabetic Ketoacidosis

TL;DR. Diabetic ketoacidosis (DKA) is a life-threatening veterinary emergency caused by severe insulin deficiency, leading to toxic ketone buildup and acidic blood, which requires immediate intensive care.

Diabetic ketoacidosis is a severe metabolic crisis that can affect both dogs and cats.

What is it?

Diabetic ketoacidosis (DKA) is a severe, life-threatening metabolic complication of diabetes mellitus. To understand DKA, it helps to understand how the body processes energy. Normally, when a dog or cat eats, their body breaks food down into glucose (sugar). Insulin, a hormone produced by the pancreas, acts like a key that allows glucose to enter the body's cells to be used for energy.

In a diabetic pet, there is either a severe lack of insulin or the body's cells cannot respond to it properly. Without insulin, glucose remains trapped in the bloodstream, leaving the cells starving. In response, the body enters a state of perceived starvation and begins rapidly breaking down stored fat to use as an alternative energy source.

This rapid fat breakdown produces organic acids called ketone bodies (including acetoacetate, beta-hydroxybutyrate, and acetone). While the body can use small amounts of ketones for energy, an excessive accumulation of these compounds is highly toxic. As ketones build up in the bloodstream (ketonemia) and spill into the urine (ketonuria), they cause the blood to become dangerously acidic—a state known as metabolic acidosis. This profound chemical imbalance affects multiple organ systems and constitutes a critical medical emergency.

Causes & risk factors

The primary cause of diabetic ketoacidosis is untreated, undiagnosed, or poorly managed diabetes mellitus. However, DKA rarely occurs in a vacuum. It is typically triggered by a combination of severe insulin deficiency and an increase in "counter-regulatory" hormones (such as cortisol, glucagon, and growth hormone) that actively oppose insulin.

These hormonal shifts are usually sparked by a concurrent illness, infection, or inflammatory condition. Common triggers in dogs and cats include pancreatitis (inflammation of the pancreas), urinary tract infections, kidney disease, heart disease, or dental infections. These concurrent conditions cause systemic inflammation. A leading veterinary textbook notes:

"A recent study in dogs found that interleukin 18 (IL-18), resistin, and granulocyte-monocyte colony-stimulating factor concentrations were significantly higher in dogs with DKA before treatment compared with after resolution of ketoacidosis, and keratinocyte chemoattractant was significantly higher in dogs with DKA compared with dogs with uncomplicated diabetes."

This complex inflammatory response makes the pet highly resistant to insulin, accelerating the breakdown of fat and the production of ketones. Any diabetic pet that develops an additional illness is at a high risk of cascading into DKA.

Signs to watch for

The signs of diabetic ketoacidosis can develop rapidly, often transitioning from the typical signs of uncomplicated diabetes to severe, systemic illness over just a few days. A leading veterinary internal medicine reference describes this progression:

"...lethargy, anorexia, vomiting) ensue as ketonemia and metabolic acidosis develop and worsen, with the severity of these signs directly related to the severity of the metabolic acidosis and the nature of concurrent disorders that are often present. The time interval from onset of the clinical signs of diabetes to development of systemic signs of DKA is unpredictable and ranges from a few days to s"

Owners should watch for the following clinical signs:

• Lethargy (Common) - Your pet may seem unusually tired, weak, or uninterested in their normal activities.
• Anorexia (Common) - A complete loss of appetite or refusal to eat.
• Vomiting (Common) - Frequent vomiting is a hallmark sign of DKA and contributes to severe dehydration.
• Polyuria and Polydipsia (Common) - Excessive urination and excessive thirst, which are primary signs of underlying diabetes.
• Weight loss (Common) - Rapid weight loss despite a previously increased appetite.
• Weakness (Common) - General muscle weakness, sometimes making it difficult for the pet to stand or walk.
• Dehydration (Common) - Dry gums, loss of skin elasticity, and sunken eyes.
• Abdominal pain (Common) - Often due to concurrent pancreatitis; your pet may tense their abdomen or cry out when touched.
• Mental dullness (Common) - Depressed mental state, confusion, or lack of responsiveness.
• Hepatomegaly (Common) - An enlarged liver, which your vet will detect during an examination.
• Cataracts (Common) - Rapidly developing cloudiness in the eyes, especially common in diabetic dogs.
• Tachypnea and Dyspnea (Common) - Rapid breathing (tachypnea) or labored breathing (dyspnea).
• Icterus (Common) - A yellowing of the gums, whites of the eyes, or skin, often associated with concurrent liver or pancreatic disease.
• Acetone odor on breath (Occasional) - A distinct, sweet, or chemical smell (resembling nail polish remover) on the pet's breath, caused by exhaled acetone.
• Slow, deep breathing (Occasional) - Also known as Kussmaul respiration, this is a deep, heavy breathing pattern where the body attempts to blow off excess carbon dioxide to compensate for the acidic blood.

Lethargy and weakness are common signs of diabetic ketoacidosis in cats.

How vets diagnose it

Diagnosing diabetic ketoacidosis requires a combination of physical examination findings and specific laboratory tests. Your vet must confirm three key criteria: the presence of diabetes mellitus, the presence of ketones, and the presence of metabolic acidosis.

To establish this diagnosis, your vet will perform several critical tests:

• Urine reagent test strips (KetoDiastix): This is a rapid screening tool used to detect both glucose and ketones in your pet's urine. The presence of both strongly suggests DKA.
• Blood gas analysis / Venous pH and bicarbonate measurement: This test measures the acidity of your pet's blood. A venous pH of less than 7.35 confirms metabolic acidosis, which is a defining feature of DKA.
• Serum beta-hydroxybutyrate measurement: Beta-hydroxybutyrate is the primary ketone body produced during DKA. Measuring its concentration in the blood provides a highly accurate assessment of the severity of ketosis.
• Acetest tablets: These are specialized tablets used to detect and semi-quantify ketone bodies in urine or blood plasma.

In addition to confirming DKA, your vet will need to perform a comprehensive diagnostic panel to evaluate your pet's overall stability and identify any concurrent diseases. As a leading veterinary textbook notes:

"Critically important information for formulating the initial treatment protocol includes hematocrit and total plasma protein concentration; serum glucose, albumin, creatinine, and urea nitrogen concentrations; serum electrolytes; venous total CO2 or arterial acid-base evaluation; and urine specific gravity."

These tests help identify severe electrolyte imbalances (such as low sodium, potassium, or phosphorus), kidney dysfunction, and dehydration levels, all of which must be addressed during treatment.

Treatment options

Treatment for diabetic ketoacidosis is highly intensive, requiring 24-hour hospitalization, continuous monitoring, and precise adjustments to therapy. The goals are to restore hydration, correct electrolyte imbalances, lower blood sugar, stop ketone production, and treat any underlying trigger diseases.

Line 1 Therapies

• Fluid Therapy / Electrolyte Replenisher (Sodium chloride): Intravenous fluid therapy is the cornerstone of DKA treatment. It restores blood volume, improves kidney perfusion, and helps flush glucose and ketones out of the body. Electrolytes, particularly potassium and phosphorus, are carefully added to the fluids, as insulin therapy will cause these levels to drop rapidly in the bloodstream.
• Insulin (Hormone - Pancreatic): Insulin therapy is essential to stop the breakdown of fat and halt ketone production. However, vets must administer insulin with extreme caution. As veterinary internal medicine texts warn, "overzealous insulin treatment can cause severe hyponatremia" (critically low blood sodium) or a rapid drop in blood sugar, which can lead to brain swelling and seizures.
• Glucose / Dextrose (Fluid Therapy / Caloric Agent): Once insulin therapy successfully lowers the blood sugar to a safer level, dextrose is added to the intravenous fluids. This allows the vet to continue administering insulin (which is still needed to clear the remaining ketones) without causing dangerously low blood sugar (hypoglycemia).

Line 2 Therapies

• Sodium Bicarbonate (Alkalinizing Agent / Electrolyte Supplement): In cases of extreme, life-threatening metabolic acidosis, your vet may administer sodium bicarbonate to help normalize the blood pH. However, this must be done with extreme care:

"Bicarbonate should never be given by bolus infusion. After 6 hours of therapy the acid-base status should be reevaluated and a new dose calculated. Once the plasma bicarbonate level is greater than 12 mEq/L, further bicarbonate supplementation is not indicated."

Nutritional Support

While long-term management of diabetes involves strict dietary guidelines (such as fat-restricted, high-fiber diets for dogs and high-protein, low-carbohydrate diets for cats), the rules change during a DKA crisis. A critical care reference emphasizes:

"...during episodes of diabetic ketoacidosis it is more important that patients eat than that they eat a specific diet aimed at long-term treatment goals."

Getting the patient to eat voluntarily helps stimulate the metabolism and aids recovery, so vets will offer highly palatable foods or use temporary feeding tubes if necessary.

Vets use urine reagent strips and blood analyzers to diagnose diabetic ketoacidosis.

Prognosis

Diabetic ketoacidosis is a grave condition, but with prompt and aggressive medical intervention, many pets can recover. Approximately 70% of dogs and cats treated for DKA survive to be discharged from the hospital.

Hospitalization is typically prolonged due to the complexity of the disease. The median hospitalization time is 6 days for dogs and 5 days for cats.

Once a pet survives the acute DKA crisis and is discharged, their long-term prognosis depends on how well their underlying diabetes can be managed and whether any chronic concurrent diseases (such as chronic kidney disease or pancreatitis) are present. With dedicated home care, including daily insulin injections, regular veterinary monitoring, and appropriate nutrition, many pets go on to live happy, high-quality lives.

Prevention

Because DKA is a complication of diabetes, preventing it relies entirely on the diligent management of your pet's diabetic condition.

• Consistent Insulin Administration: Always give insulin exactly as prescribed by your veterinarian. Never adjust the dose or skip a dose without consulting your vet.
• Routine Monitoring: Perform regular blood glucose curves or bring your pet in for routine fructosamine tests and checkups as recommended.
• Prompt Medical Attention: If your diabetic pet shows any signs of mild illness, such as a decreased appetite, mild lethargy, or a change in water consumption, seek veterinary care immediately. Treating a minor infection or flare-up early can prevent it from triggering a DKA crisis.
• Dietary Consistency: Feed your pet a consistent diet at scheduled times to help maintain stable blood sugar levels.

When to call your vet

Diabetic ketoacidosis is a medical emergency. If your pet has been diagnosed with diabetes, or if you suspect they may be diabetic, you must act quickly if they show signs of illness.

Seek immediate emergency veterinary care if your pet exhibits any of the following red flags:

• Frequent vomiting or inability to keep water down
• Extreme lethargy, weakness, or collapse
• Rapid, heavy, or labored breathing
• Complete refusal to eat for more than 12 to 24 hours
• A sweet, chemical, or nail-polish-remover-like odor on their breath
• Severe depression or lack of responsiveness

Do not wait to see if these signs improve. Early intervention is the single most important factor in saving a pet's life during a DKA crisis.

Sources

• Internal Medicine, 5th Edition, pages 843, 844, 847.
• Small Animal Critical Care Medicine, 2nd Edition, pages 384, 385, 387.