When to see a vet urgently
The following signs in a cat with diabetes or receiving diabetes medication require immediate contact:
- Your cat stops eating, vomits or becomes markedly tired.
- Breathing is deep, fast or laboured.
- Your cat is weak, seems dehydrated or has altered consciousness.
- Ketones are found in the blood or urine of an ill cat.
Do not wait for an acetone smell or a high home reading before making contact. You can find a vet near you.
Overview
Without enough insulin, cells cannot use glucose despite high blood levels. The body switches to fat metabolism, producing ketones: acetoacetate, beta-hydroxybutyrate and acetone. Excessive amounts cause acidosis and toxic stress on the central nervous system, potentially leading to coma and requiring intensive care.
Glucose is usually high in ordinary DKA, but exceptions occur. In euglycaemic ketoacidosis, it is not markedly raised despite ketoacidosis. This may occur particularly in cats receiving oral SGLT2 inhibitors. These medicines reduce glucose reabsorption in the kidneys and increase its loss in urine. A normal glucose result in an ill cat therefore does not reliably exclude danger.
Acidosis means excessive acidification of the blood. A mild ketone increase, or ketosis, is not always the same as ketoacidosis. Diagnosis combines ketone findings, acid–base balance and condition. Do not try to settle the distinction from one strip's colour at home if your cat is clearly ill.
Causes
Diabetic ketoacidosis develops in these situations:
- Poorly controlled diabetes.
- Abrupt cessation of insulin treatment.
- Infections involving the urinary tract, respiratory tract or abscesses.
- Pancreatitis.
- Chronic kidney disease.
- Stress and surgery.
- Certain medicines, including glucocorticoids and progestogens.
DKA can also be the first sign of previously unrecognised diabetes. It therefore does not always result from an error in existing care. Concurrent inflammation or another illness can reduce insulin effectiveness and increase metabolic strain.
Insulin may be insufficient relative to the body's needs even when given in a previously effective way. Pancreatitis and infections can change requirements, for example. Investigating an unwell diabetic cat therefore goes beyond confirming the latest injection was given.
Risk factors
DKA occurs more often in:
- Elderly cats with diabetes.
- Obese cats.
- Cats receiving an incorrect insulin amount.
- Cats with chronic infections or inflammatory diseases.
- Stressed cats.
Obesity and age primarily relate to the risk of developing diabetes. They do not alone predict which cat will develop ketoacidosis. Information on individual feline DKA risks is limited, and a thin or previously untreated cat can also become seriously ill. Do not infer from the list that a normal-weight or regularly medicated cat is certainly safe.
Main symptoms
Typical signs include:
- Tiredness and listlessness.
- Loss of appetite.
- Excessive urination and thirst, or polyuria and polydipsia.
- Vomiting and diarrhoea.
- An acetone smell on the breath.
- Dehydration and dry mucous membranes.
- Rapid breathing, described as Kussmaul breathing.
- Weakness and loss of coordination.
- Coma in severe cases.
Diabetes may initially cause increased drinking, urination and weight loss. With ketoacidosis, appetite loss, vomiting and tiredness indicate a marked deterioration. Signs can still resemble other diseases. DKA cannot be reliably distinguished at home from another severe illness or treatment-related low blood glucose, for example.
Complications and consequences
Without prompt care, DKA leads to:
- Severe dehydration and electrolyte disturbances.
- Brain swelling.
- Multiple organ failure.
- Death.
Electrolyte disturbances can affect muscles and heart rhythm. Potassium, phosphate and glucose can change during treatment too, requiring close monitoring. Your cat therefore needs correction of the whole metabolic situation rather than a single insulin administration.
These severe consequences do not mean every treated cat loses the chance of recovery. Severity and concurrent problems affect the prognosis. DKA alone also does not rule out later diabetes remission, in which insulin needs may decrease or disappear under veterinary supervision.
Diagnosis at the vet
Diagnosis uses:
- Blood tests for hyperglycaemia, acidosis and electrolyte disturbances.
- Urine tests for ketones and glucose.
- Blood biochemistry to assess liver and kidney function.
- Pancreatic ultrasound for pancreatitis as a possible trigger.
Blood acidity and electrolytes are assessed alongside ketones. Blood beta-hydroxybutyrate, or BHB, can be measured; it is a major ketone produced in DKA. Routine urine ketone strips measure a different ketone, acetoacetate. Blood BHB can rise before urine strips show ketones.
A negative urine strip therefore does not alone provide reassurance if your cat will not eat and is unwell. Conversely, a small ketone finding in a well cat does not automatically equal severe DKA. The vet assesses it alongside other measurements and provides further instructions.
Investigating underlying disease may require urine culture, pancreatic blood tests or abdominal ultrasound. Ultrasound is not the only method for investigating pancreatitis. Report all diabetes medicines, appetite changes, recent drinking and urination, and previous care instructions.
Hospital treatment
A symptomatic DKA patient usually needs hospital care. Fluids correct dehydration and support circulation, while electrolytes are supplemented according to measurements. Insulin reduces ketone formation. Any disease triggering ketoacidosis is investigated and treated at the same time.
Glucose, ketones and electrolyte balance are checked repeatedly. A marked phosphate decrease can particularly damage feline red blood cells. Acidosis and ketosis need monitoring even after glucose falls. One good-looking glucose result therefore does not alone show treatment is complete.
Euglycaemic ketoacidosis requires insulin despite glucose not being high. Hospital care may provide glucose simultaneously so insulin can correct ketosis without dangerous hypoglycaemia. This combination belongs to supervised treatment and should not be attempted at home.
An unwell cat receiving an SGLT2 inhibitor
If a cat receiving this medicine group stops eating, vomits or becomes listless, stop administration and contact a vet immediately. A normal glucose metre result does not change the need for contact. Mention the medication at an emergency practice unfamiliar with your cat too.
The glucose effect can persist after stopping, so treatment needs may not disappear as soon as the next administration is omitted. Diabetes care is replanned after ketoacidosis; these patients generally move to insulin treatment. Do not restart the product at home solely because appetite returns.
Discharge and monitoring
Home care needs a clear plan for medication, feeding and what to do during illness. Seek immediate instructions if an insulin-treated cat will not eat or vomits; do not increase insulin or stop treatment yourself. Practical administration difficulties are also discussed before discharge.
Monitor appetite, weight, drinking, urination and activity, alongside agreed home or practice measurements. Glucose may be monitored through blood samples or a continuous sensor. The vet determines when ketone testing is also needed. Keep results and symptom observations in one diary so their timing can be compared.
A single high practice glucose result may also reflect stress. Monitoring therefore considers all measurements and condition. Do not dismiss new appetite loss and tiredness because the last check was good. A new concurrent disease can alter previously effective treatment requirements.
Prevention
Good diabetes management can prevent DKA:
- Regular insulin injections according to veterinary instructions.
- Following the diet and treatment plan.
- Monitoring glucose and ketones with urine and blood tests.
- Regular veterinary visits to review treatment.
- Prompt treatment of infections and inflammatory diseases.
Good care and monitoring reduce risk, but cannot guarantee prevention in every situation. An appropriately treated cat can also develop a triggering illness. Prevention therefore needs a sick-day plan and early recognition of deterioration alongside it.
Important for cat owners
Diabetic ketoacidosis is life-threatening. Remember that tiredness, vomiting, loss of appetite and an acetone smell on a diabetic cat's breath warrant immediate veterinary attention. The prognosis is reasonable early on, but the risk of death without treatment is very high.
This material provides information and does not replace treatment advice. Contact a vet as soon as the first symptoms appear.
Frequently asked questions
Can normal blood glucose rule out DKA?
Not reliably. A cat receiving an SGLT2 inhibitor in particular may have euglycaemic ketoacidosis without markedly raised glucose. Ketones and acid–base balance need veterinary assessment in a cat that will not eat, vomits or is tired.
Do urine ketones always mean ketoacidosis?
Not alone. Ketones can occur without confirmed acidosis, so findings are interpreted alongside condition and other tests. In an ill diabetic cat, they nevertheless warrant urgent assessment. A negative strip also does not reliably exclude an early problem.
Can a cat recover from ketoacidosis?
Yes, but it is life-threatening and needs prompt treatment. Dehydration, metabolic disturbances and underlying diseases affect the prognosis. Diabetes care continues individually after recovery, and previous DKA alone does not prevent later remission.
This article is for general information only and is not a guide to treatment. If you notice the first signs of illness, contact your vet.
Paw4care editorial team
Sources
- Section 12: Diabetic Ketoacidosis in Cats, American Animal Hospital Association, accessed 2026-11-03.
- Section 6: SGLT2 Inhibitor Treatment and Monitoring, American Animal Hospital Association, accessed 2026-11-03.
- iCatCare 2025 consensus guidelines on the diagnosis and management of diabetes mellitus in cats, Journal of Feline Medicine and Surgery / International Cat Care, accessed 2026-11-03.
- Diabetic Ketoacidosis in Cats, VCA Animal Hospitals, accessed 2026-11-03.
- Feline Diabetes, Cornell University College of Veterinary Medicine, accessed 2026-11-03.
- Diabetes Mellitus in Dogs and Cats, Merck Veterinary Manual, accessed 2026-11-03.