Diabetes in dogs and cats: signs, treatment routines and monitoring

Diabetes mellitus is a long-term condition in which too little effective insulin leaves too much glucose in the bloodstream.

Insulin normally helps glucose enter cells for energy. When insulin production or action is inadequate, glucose builds up in the blood and spills into urine, while the body cannot use fuel normally. [1]

Diabetes makes dogs and cats urinate more because excess glucose passes into the urine and draws water with it.

The resulting water loss makes the pet drink more to compensate. Increased thirst and larger or more frequent wees are therefore common early clues, especially when they occur alongside appetite or weight changes. [1]

Yes. A diabetic pet may eat eagerly yet lose weight because its cells cannot use glucose normally as an energy source.

The body then turns to stored fat and muscle for fuel, so weight can fall despite a strong appetite. Some unwell diabetic pets instead lose their appetite, making the overall pattern important. [1]

Vets diagnose clinical diabetes by combining the pet's signs with evidence that blood glucose stays high and glucose is present in the urine.

One high reading is not always enough, particularly in cats because stress can temporarily raise glucose. The veterinary team may use repeat samples, fructosamine or home glucose information to show that the change is persistent. [2]

A wider assessment helps the vet look for diabetes complications and other illnesses that could make the pet unwell or harder to stabilise.

Urine, blood and physical-examination findings can reveal problems such as infection, pancreatitis, kidney disease or another hormone disorder. The exact tests depend on the pet's species, signs, medicines and general condition. [2]

Diabetic ketoacidosis, or DKA, is a life-threatening diabetes complication in which ketone acids build up and severely disrupt the body's fluid, electrolyte and acid balance.

It develops when cells cannot access enough glucose and the body breaks down fat for energy. Affected pets are usually systemically unwell and need urgent veterinary assessment and hospital-level treatment.

Ketones are by-products of fat metabolism. When too many accumulate, they change the blood's pH and can disrupt several body systems. [1]

Poor appetite, vomiting, dehydration, marked tiredness or weakness in a diabetic pet can signal diabetic ketoacidosis and require urgent veterinary assessment.

These signs are not unique to DKA, but the combination matters because this complication can worsen quickly. It may occur when diabetes is first discovered or in a pet already receiving treatment, especially alongside another illness. [2]

Hypoglycaemia means blood glucose has fallen too low, and it is a potentially dangerous complication of diabetes treatment.

It can happen when the glucose-lowering effect of treatment such as insulin is greater than the pet's current needs, including around changes in appetite, activity or illness. Suspected hypoglycaemia warrants prompt veterinary guidance because severe cases can affect the brain.

An incorrectly given insulin dose can also cause low blood glucose. [3]

Signs of low blood sugar can include unusual sleepiness, weakness, strange behaviour, an unsteady walk, trembling or seizures.

The signs can start subtly and become severe. A treated diabetic pet with sudden neurological signs needs immediate veterinary guidance; collapse, poor responsiveness or seizures are an emergency. [4]

Yes. A cat receiving an SGLT2 diabetes medicine can develop ketoacidosis even when blood glucose is not markedly high.

This uncommon but life-threatening complication is why careful patient selection, ketone monitoring and attention to appetite, vomiting, hydration and general wellbeing are central to this treatment. An unwell treated cat warrants urgent veterinary assessment. [19]

Fructosamine gives the veterinary team a picture of the pet's average blood-glucose control over recent weeks rather than at one moment.

It can help distinguish a persistent problem from a temporary stress response and can show whether control is changing over time. Other illnesses can affect the result, so it is interpreted with signs, weight and other monitoring information. [5]

Appetite, thirst, urination, body weight, energy and any return of earlier diabetes signs are useful parts of home monitoring.

A simple record helps the veterinary team interpret glucose information in the context of how the pet is actually feeling. Changes in these signs can matter even when a single meter or urine result appears reassuring.

Home blood-glucose testing with small pin-prick samples or a continuous glucose monitor can also help the veterinary team see glucose patterns in the home environment, with less influence from stress-related rises. [6]

Yes. Many diabetic dogs and cats can remain comfortable and enjoy a good quality of life with a workable treatment and monitoring routine.

Finding stable control can take time, and the plan may need adjustment as the pet's weight, appetite, activity or other health problems change. Clear veterinary support helps families manage those changes without expecting perfection from every reading. [4]

Common signs of diabetes in dogs include increased thirst and urination, a strong appetite with weight loss, tiredness, weakness and poorer body condition.

The changes often develop gradually, so a fuller water bowl, more requests to go outside or unexplained weight loss may be noticed separately. Cataracts can also be an important clue in dogs. [2]

Yes. Diabetes commonly causes cataracts in dogs because excess glucose changes the lens, making it swollen and cloudy.

Cloudiness can progress and reduce vision, sometimes quickly. A diabetic dog's eye changes therefore need veterinary assessment, both to judge vision and to look for painful inflammation or other eye problems. [1]

Yes. Clinical diabetes in dogs requires prescribed insulin because the dog's own insulin supply is not sufficient to control blood glucose.

The suitable product and schedule are individual veterinary decisions. Food intake, body weight, signs and glucose monitoring all help the veterinary team judge how well the plan is working and whether it needs changing. [7]

Naturally acquired diabetes in dogs very rarely goes into remission, so it is usually managed as a lifelong condition.

There are unusual situations in which a reversible cause of insulin resistance contributes to diabetes. A vet therefore looks for underlying disease, relevant medicines and hormonal factors, but families should not assume routine canine diabetes will disappear. [7]

Many diabetic dogs can do well on a complete, balanced and palatable diet that provides predictable intake at consistent times and in consistent amounts.

There is no single best food for every dog. Body weight, other illnesses and the dog's willingness to eat shape the veterinary nutrition plan, while consistency helps make the glucose response easier to interpret. [8]

A healthy, stable body weight supports diabetes care because both obesity and ongoing diabetes-related weight loss can complicate control.

Weight trends also show whether the dog is using food more effectively as treatment settles. Calorie changes are tailored gradually around body condition, muscle condition, activity and any other disease rather than a generic target. [8]

A blood-glucose curve shows how glucose changes across an insulin cycle, including how low it falls and how long the insulin effect lasts.

That pattern can reveal low glucose that causes no obvious signs and can help explain poor control. A curve is interpreted alongside appetite, thirst, urination, weight and the dog's normal feeding routine because readings vary between days.

Routine glucose curves can help your vet tailor treatment remotely, particularly when the dog is stable. Ask your veterinary team how and when to provide these records. [9]

No. Urine glucose can be useful during the initial diagnosis, but it is not accurate or detailed enough to guide a diabetic dog's ongoing care by itself.

A urine result reflects the period while the bladder was filling rather than the dog's glucose at that moment. Dipsticks can also underestimate glucose in dogs, so the result is combined with clinical signs and other measurements.

Ask your vet whether urine ketone testing should be included in the monitoring plan; it can show whether ketones are present and whether positive results are becoming more frequent. [10]

Hormonal changes after a season can cause insulin resistance in an unneutered female dog and may contribute to diabetes or make it harder to control.

This is a dog-specific effect linked to progesterone and growth hormone. The veterinary team considers reproductive status and timing when assessing the cause, and may discuss surgery as part of the individual management plan. [1]

Common signs of diabetes in cats include increased thirst and urination, increased appetite despite weight loss, and tiredness.

The pattern is not identical in every cat. Other illnesses can alter appetite or energy, so a cat can still have diabetes without displaying every classic sign. [11]

Yes. Diabetes can damage peripheral nerves in cats, causing weakness in the back legs and a lowered, flat-footed stance.

A cat may become reluctant or unable to jump, walk differently or place more of the back leg on the floor. Other neurological and orthopaedic problems can look similar, so the sign needs veterinary assessment. [12]

Yes. Stress can temporarily raise a cat's blood glucose, so an isolated high reading does not always mean the cat has diabetes.

The distinction matters most when typical diabetes signs are absent. A vet may look for evidence that high glucose persists through repeat testing, fructosamine or measurements taken in a calmer or home environment. [13]

Feline diabetes is confirmed by showing that high blood glucose is sustained, not simply a short-lived response to stress.

The evidence may come from fructosamine, repeat blood or urine findings, or glucose information gathered in a calmer or home setting. Results are interpreted alongside signs such as thirst, urination, appetite and weight change. [14]

No. A cat in diabetic remission is not cured because its reserve of insulin-producing cells remains limited and diabetes can return.

Ongoing attention to weight, diet and familiar diabetes signs remains useful after treatment has stopped. Renewed thirst, urination, appetite change or weight loss can justify reassessment for relapse or another health problem. [15]

A cat entering remission may need progressively less insulin or begin showing glucose readings or signs that suggest blood sugar is becoming too low.

Regular monitoring makes this transition easier to recognise before severe hypoglycaemia develops. Treatment changes remain veterinary decisions because the same findings can have more than one explanation and oral medicines affect glucose tests differently. [15]

Many diabetic cats benefit from a complete, balanced diet that is high in protein and lower in carbohydrate, provided they will eat it reliably.

Reliable food intake comes before chasing an ideal nutrient profile, and another illness may change the priority. The plan also considers body weight, muscle condition, appetite and whether the cat eats meals or grazes. [16]

No. Portioned meals can make appetite and intake easier to track, but strict meal feeding is not essential for every diabetic cat.

Some cats naturally graze and may continue to do so if changing that pattern would reduce reliable intake. Feeding arrangements are matched to the cat's treatment, weight goals and established eating behaviour.

Work with your veterinary team to establish a routine for dosing, feeding and day-to-day care. Inconsistency can make diabetes harder to stabilise. [16]

Body weight matters because obesity can worsen insulin resistance, while uncontrolled diabetes can cause harmful loss of fat and muscle.

The aim is a gradual move towards a healthy, stable body and muscle condition, not rapid dieting. Serial weights also help show whether clinical control and food intake are improving or whether another illness needs attention. [16]

A continuous glucose monitor can show glucose patterns across day and night without repeatedly taking blood samples from the cat.

It provides more context than a single reading and can reveal otherwise unnoticed low glucose. Sensor readings, particularly unexpectedly low ones, still need interpretation alongside the cat's signs and veterinary-quality blood-glucose information. [17]

No. Urine glucose can sometimes add context, but it is too indirect and imprecise to replace the wider monitoring plan for a diabetic cat.

A result reflects average glucose while the bladder was filling and cannot show how low the blood glucose fell. This is especially important because a negative urine result can fit either tight control or dangerous hypoglycaemia.

Urine ketone testing is a separate test your vet may recommend to check whether ketones are present. [18]

A diabetic cat's thirst, urination, appetite, energy and weight show whether treatment is improving everyday health, which is the main goal of care.

Glucose measurements provide valuable detail but can vary or miss important periods. A steady weight and controlled signs therefore give the veterinary team essential context when deciding whether a numerical result truly represents good clinical control. [18]