Diabetes in Dogs: Signs, Insulin Treatment and Long-Term Care
Diabetes mellitus is one of the more common endocrine diseases affecting dogs. It occurs when the body is unable to regulate blood glucose normally because there is insufficient effective insulin.
Most diabetic dogs require long-term insulin treatment, together with a consistent feeding routine, appropriate exercise and regular monitoring.
With careful management, many diabetic dogs can maintain a good quality of life for many years.
What Is Diabetes in Dogs?
Glucose is an important source of energy for the body's cells. Insulin is a hormone produced by the pancreas which allows glucose to move from the bloodstream into cells where it can be used for energy.
In most diabetic dogs, the pancreas does not produce enough insulin to maintain normal blood glucose regulation.
Without sufficient insulin, glucose remains within the bloodstream instead of being used normally by the body's tissues. Blood glucose concentrations rise and glucose eventually begins to pass into the urine.
Glucose within the urine draws additional water with it, which is why increased thirst and urination are among the classic signs of canine diabetes.
What Are the Signs of Diabetes in Dogs?
Common Early Signs
- Increased thirst
- Increased urination
- Weight loss
- Increased appetite
- Reduced energy
Other Possible Signs
- Changes in coat condition
- Muscle loss
- Recurrent infections
- Cloudiness of the eyes or cataracts
- Reduced activity
Signs Requiring Prompt Attention
- Vomiting
- Marked lethargy
- Loss of appetite
- Weakness or collapse
- Dehydration
- Abnormal breathing
Excessive drinking is often one of the first changes owners notice.
You can read more about other possible causes of increased thirst here: Why Is My Dog Drinking So Much Water?
How Is Diabetes Diagnosed?
Diagnosis is usually based on a combination of compatible clinical signs and evidence of persistently increased blood glucose.
Investigation may include:
- Blood glucose measurement
- Urinalysis to check for glucose and ketones
- General blood tests
- Assessment of kidney and liver parameters
- Investigation for concurrent disease where appropriate
A single elevated blood glucose result does not always provide the complete picture. Your veterinary surgeon will interpret laboratory findings alongside the dog's clinical signs and medical history.
Additional tests such as fructosamine measurement may sometimes be useful when assessing average blood glucose control over a longer period.
Insulin Treatment for Dogs
Most dogs with diabetes are insulin deficient and therefore require replacement insulin therapy.
Insulin allows glucose to move from the bloodstream into cells, helping restore normal energy metabolism and reduce persistently high blood glucose concentrations.
Treatment is tailored to the individual dog. The insulin preparation, dose, injection schedule and feeding routine are determined by the prescribing veterinary surgeon.
Porcine Insulin Zinc Suspension
Porcine insulin zinc suspension is an active substance used in authorised veterinary insulin preparations for the treatment of diabetes mellitus in dogs.
It is administered by subcutaneous injection, with the dose adjusted according to the individual dog's response to treatment.
Insulin requirements cannot be determined from body weight alone. Dogs vary considerably in their response to insulin, which is why appropriate monitoring is essential during treatment.
How Is Insulin Given?
Insulin is administered by injection beneath the skin. Many diabetic dogs receive insulin at regular intervals alongside a consistent feeding schedule.
Your veterinary team should demonstrate the correct injection technique and explain how to measure and administer the prescribed amount safely.
Insulin may be administered using an appropriate insulin syringe or a compatible insulin pen device depending on the insulin preparation and the veterinary surgeon's instructions.
Different insulin preparations may be supplied at different concentrations. The syringe or delivery device must therefore be appropriate for the insulin being administered. Always follow the instructions provided by your veterinary surgeon.
Monitoring Diabetes in Dogs
Monitoring is an essential part of diabetes management because insulin requirements can change over time.
The goal is not necessarily to make every individual glucose reading completely normal. Instead, treatment aims to achieve good overall diabetic control while avoiding dangerously low blood glucose concentrations.
Monitoring may include:
- Changes in thirst and urination
- Body weight
- Appetite and energy levels
- Blood glucose measurements
- Blood glucose curves
- Fructosamine measurement
- Continuous or intermittent glucose monitoring
- Urine glucose or ketone testing where advised
Blood Glucose Monitoring at Home
Some owners monitor their dog's blood glucose at home alongside regular veterinary assessment.
Home monitoring can provide useful information because readings can be obtained in the dog's normal environment and can help veterinary teams assess glucose trends throughout the day.
Monitoring results should always be interpreted alongside the dog's clinical signs. Insulin doses should not be changed solely on the basis of an individual home glucose reading unless this has been specifically discussed with the veterinary surgeon managing the case.
AlphaTrak Blood Glucose Monitoring
AlphaTrak systems are designed for blood glucose monitoring in dogs and cats and can be used to obtain spot glucose measurements or construct home glucose curves where advised by a veterinary professional.
View AlphaTrak
Continuous Glucose Monitoring
Continuous glucose monitoring sensors such as FreeStyle Libre can also be used by veterinary teams in selected diabetic dogs to obtain repeated interstitial glucose measurements over time.
These systems can provide useful information about glucose trends without requiring repeated blood sampling throughout the day.
View FreeStyle Libre 2 PlusUsing Libre Sensors in Diabetic Dogs
Continuous glucose monitoring has become increasingly useful in veterinary diabetes management.
FreeStyle Libre sensors measure glucose within the interstitial fluid rather than directly measuring blood glucose. A sensor is applied to the skin and can provide repeated glucose measurements over several days.
This can help identify:
- Changes in glucose throughout the day
- Periods of unexpectedly low glucose
- Periods of persistent hyperglycaemia
- The approximate timing of the lowest glucose concentration after insulin administration
- Day-to-day glucose trends
Continuous monitoring can be particularly useful when a conventional glucose curve is difficult to obtain or when a veterinary surgeon wants a broader picture of glucose variation over time.
Continuous glucose monitors measure glucose in interstitial fluid rather than directly in blood. Sensor values may therefore differ from a simultaneous blood glucose measurement, particularly when glucose concentrations are changing rapidly. Results should be interpreted in conjunction with clinical signs and veterinary guidance.
Urine Monitoring at Home
Urine testing can provide additional information when managing a diabetic dog, particularly when checking for glucose or ketones.
Urine glucose does not provide the same information as a blood glucose measurement and should not normally be used by itself to adjust an insulin dose.
However, monitoring for ketones can be particularly useful because ketone production may indicate inadequate diabetic control or developing diabetic ketoacidosis.
Urine Collection
A clean urine sample can be useful for checking glucose, ketones and other urinary parameters where home testing has been advised.
View Urine Collection Kit
Urine Test Strips
Urine test strips can be used to monitor parameters including glucose and ketones where recommended as part of a dog's diabetes monitoring plan.
View Urine Test StripsWhat Is a Blood Glucose Curve?
A blood glucose curve involves measuring glucose repeatedly over a period of time following insulin administration.
The resulting pattern can help the veterinary surgeon assess how glucose changes during the dosing interval and whether the current treatment plan appears appropriate.
A glucose curve may be performed using repeated blood glucose measurements or, in some cases, information obtained from a continuous glucose monitoring sensor.
An individual glucose curve should not be interpreted in isolation. Appetite, thirst, urination, body weight and the dog's overall clinical response are all important when assessing diabetic control.
Hypoglycaemia: When Blood Glucose Becomes Too Low
One of the most important potential complications of insulin treatment is hypoglycaemia, where blood glucose falls too low.
Possible signs include:
- Weakness
- Unsteadiness
- Disorientation
- Trembling
- Unusual behaviour
- Collapse
- Seizures
If a diabetic dog develops weakness, collapse, seizures or other signs suggestive of significantly low blood glucose, seek urgent veterinary advice. Owners of diabetic dogs should discuss an individual emergency plan with their veterinary practice.
Diabetic Ketoacidosis
Diabetic ketoacidosis, often shortened to DKA, is a serious complication of diabetes.
When insufficient insulin is available, the body begins breaking down fat for energy and produces substances called ketones. Excessive accumulation of ketones can result in severe metabolic disturbance.
Dogs with diabetic ketoacidosis may show:
- Loss of appetite
- Vomiting
- Marked lethargy
- Weakness
- Dehydration
- Abnormal breathing
- Collapse
Suspected diabetic ketoacidosis requires urgent veterinary treatment.
Diet and Feeding
A consistent feeding routine is an important part of managing canine diabetes.
The most appropriate diet depends on the individual dog's body condition, concurrent diseases and nutritional requirements.
Consistency in the amount and timing of food can help make the dog's response to insulin more predictable.
Sudden major dietary changes should therefore be discussed with the veterinary surgeon managing the diabetes.
Exercise and Diabetes
Regular exercise is beneficial for many diabetic dogs, but consistency is important.
A sudden increase in activity can increase glucose utilisation and potentially alter insulin requirements. A reasonably consistent level of exercise from day to day can therefore make diabetic management easier.
Long-Term Care for Diabetic Dogs
Successful long-term management generally involves:
- Giving insulin consistently as prescribed
- Maintaining a regular feeding routine
- Keeping exercise reasonably consistent
- Monitoring thirst, urination, appetite and body weight
- Using blood or continuous glucose monitoring where appropriate
- Monitoring urine where advised
- Attending regular veterinary reviews
Insulin requirements may change with time because of changes in body weight, diet, activity, concurrent disease or other medications.
Regular reassessment allows the treatment plan to evolve with the individual dog.
Frequently Asked Questions
Can diabetes in dogs be cured?
Diabetes in dogs generally requires lifelong management. Unlike some diabetic cats, remission is uncommon in dogs, so ongoing insulin treatment is usually required.
How often do diabetic dogs need insulin?
The dosing schedule depends on the insulin preparation and the individual dog. Many diabetic dogs receive insulin at regular intervals each day, but the exact schedule must be prescribed by the veterinary surgeon managing the case.
Can I monitor my dog's glucose at home?
Yes. Some dogs are monitored at home using pet blood glucose meters or continuous glucose monitoring sensors. Your veterinary team can advise which approach is appropriate and how the results should be interpreted.
Can Libre sensors be used in dogs?
Continuous glucose monitoring sensors such as FreeStyle Libre are used by veterinary teams in some diabetic dogs to monitor interstitial glucose trends over time. The results need to be interpreted appropriately because sensor glucose and blood glucose are not identical measurements.
Why is my diabetic dog still drinking a lot?
Persistent excessive thirst can indicate that blood glucose control is not yet optimal, although other medical conditions can also cause increased drinking. A change in thirst should be discussed with your veterinary surgeon rather than adjusting the insulin dose without guidance.
What happens if my dog misses an insulin injection?
Contact your veterinary practice for advice. Do not give additional insulin or substantially alter the next dose unless instructed to do so, because inappropriate insulin administration can cause dangerous hypoglycaemia.