# Decoding Hyperglycemia and Hypoglycemia in Dogs and Cats ## Quick Answer - Hyperglycemia in dogs and cats requires distinguishing transient stress-related glucose elevation from persistent diabetes mellitus using serial measurements and clinical context. - Hypoglycemia demands urgent investigation because causes range from insulin overdose to sepsis, hepatic disease, and insulin-secreting tumors. - A single glucose reading is insufficient for diagnosis, paired history, physical examination, and laboratory tests such as fructosamine and insulin concentrations guide the differential. ## At a Glance | Condition | Typical Signalment and History | Key Laboratory Findings | Initial Clinical Approach | |---|---|---|---| | Stress hyperglycemia | Cats with acute illness, hospitalization, or handling, dogs with excitement or pain | Mild to moderate glucose elevation, normal fructosamine, no glucosuria in most cases | Recheck glucose after acclimation, measure fructosamine, treat underlying stressor | | Diabetes mellitus | Older dogs and cats with polyuria, polydipsia, weight loss, and polyphagia | Persistent hyperglycemia, glucosuria, elevated fructosamine, possible ketonuria | Confirm with serial glucose and fructosamine, initiate insulin therapy under veterinary supervision | | Hypoglycemia from insulinoma | Middle-aged to older dogs with episodic weakness, collapse, or seizures after fasting | Low glucose with high insulin concentration, low insulin-to-glucose ratio | Measure paired glucose and insulin, pursue imaging, refer for surgical evaluation | | Hypoglycemia from sepsis | Critically ill animals with fever, lethargy, or shock | Low glucose, elevated lactate, evidence of infection | Stabilize circulation, treat underlying infection, monitor glucose frequently | | Hypoglycemia from hepatic insufficiency | Animals with vomiting, jaundice, or neurologic signs | Low glucose, elevated liver enzymes, low albumin, possible hyperbilirubinemia | Assess liver function, provide glucose support, investigate hepatic disease | ## Clinical Relevance of Glucose Abnormalities Glucose homeostasis depends on the balance between insulin secretion, hepatic glucose production, and peripheral glucose utilization. In companion animals, disruptions in this balance produce two common clinical presentations: hyperglycemia and hypoglycemia. Each has a broad differential that spans endocrine, metabolic, infectious, and neoplastic causes. The diagnostic approach must integrate the signalment, history, physical examination findings, and laboratory data instead of relying on a single glucose measurement. The American Veterinary Medical Association emphasizes that pet owners should seek veterinary care for any persistent change in appetite, thirst, urination, or energy level. These signs often accompany glucose disorders and warrant professional evaluation. The American Animal Hospital Association similarly recommends routine preventive care examinations that include screening for metabolic conditions, particularly in middle-aged and older animals. ## Core Principles of Glucose Regulation Insulin is the primary hormone that lowers blood glucose by promoting cellular uptake and hepatic storage. Glucagon, cortisol, epinephrine, and growth hormone raise glucose through glycogenolysis, gluconeogenesis, and reduced peripheral utilization. The balance between these hormones maintains glucose within a narrow range in healthy animals. In diabetes mellitus, either absolute insulin deficiency or insulin resistance leads to persistent hyperglycemia. When glucose exceeds the renal threshold, glucosuria occurs, producing osmotic diuresis and the classic signs of polyuria and polydipsia. In cats, stress-induced hyperglycemia can mimic diabetes because epinephrine and cortisol release during handling or hospitalization can raise glucose concentrations substantially. Hypoglycemia occurs when glucose production fails to match glucose utilization. The brain depends on glucose as its primary fuel, so neurologic signs dominate the clinical presentation. The differential for hypoglycemia includes insulinoma, sepsis, hepatic failure, hypoadrenocorticism, and certain toxins. ## Clinical Presentation and History ### Hyperglycemia Signs Animals with diabetes mellitus typically present with polyuria, polydipsia, polyphagia, and weight loss. Owners may report increased water consumption, more frequent urination, or accidents in the house. Some animals develop cataracts, particularly dogs, because the lens accumulates sorbitol when glucose is elevated. Cats may show a plantigrade stance if diabetic neuropathy develops. Stress hyperglycemia in cats is often asymptomatic. The elevation is detected during routine blood work or during evaluation for another condition. The glucose concentration may be markedly elevated, sometimes exceeding 300 mg/dL, yet the cat shows no signs of diabetes. ### Hypoglycemia Signs Hypoglycemia produces neurologic signs because the brain cannot store glucose. Clinical signs include weakness, lethargy, ataxia, tremors, collapse, and seizures. The signs often occur after fasting or after exercise, and they may resolve after eating. In insulinoma, the signs typically occur several hours after a meal when glucose has been cleared from the blood. The severity of signs correlates with the rate of glucose decline and the absolute glucose concentration. A rapid drop from normal to moderately low levels can cause profound signs, whereas a gradual decline may produce only subtle weakness. ## Diagnostic Workup ### Initial Assessment The first step is to confirm the glucose abnormality with a blood sample. Point-of-care glucometers are convenient but can be inaccurate at very low or very high glucose concentrations. A laboratory glucose measurement provides a more reliable baseline. The physical examination should include assessment of hydration status, body condition, mentation, and abdominal palpation. The presence of hepatomegaly, a pancreatic mass, or signs of sepsis changes the differential. ### Serial Glucose Measurements A single glucose reading is rarely sufficient. Serial measurements over several hours or days help distinguish persistent hyperglycemia from transient stress-related elevation. In cats, a glucose curve performed in the hospital can show whether glucose remains elevated when the animal is calm. For hypoglycemia, a glucose curve can document the timing of the low episodes and correlate them with meals or activity. The curve also helps determine whether the hypoglycemia is fasting-related or postprandial. ### Fructosamine Fructosamine is a glycated protein that reflects the average glucose concentration over the preceding two to three weeks. It is useful in distinguishing stress hyperglycemia from diabetes mellitus. In stress hyperglycemia, the fructosamine concentration is normal because the glucose elevation is transient. In diabetes mellitus, the fructosamine is elevated because the glucose has been persistently high. Fructosamine is also useful for monitoring the response to insulin therapy. A declining fructosamine concentration indicates improved glycemic control. ### Insulin Concentration An insulin concentration is measured when hypoglycemia is present. The sample should be collected at the time of hypoglycemia, ideally when the glucose is below the reference range. A high insulin concentration in the presence of hypoglycemia indicates an insulin-secreting tumor or exogenous insulin administration. The insulin-to-glucose ratio can be calculated, but the interpretation requires clinical context. A low glucose with a high insulin concentration is diagnostic of insulinoma in most cases. ### Additional Laboratory Tests A complete blood count, serum biochemistry profile, and urinalysis are essential. The biochemistry profile can identify hepatic disease, renal disease, or electrolyte abnormalities. The urinalysis can detect glucosuria, ketonuria, or urinary tract infection. In animals with hypoglycemia, additional tests may include liver function tests, bile acids, and cortisol levels to assess for hypoadrenaline. Imaging with abdominal ultrasound or computed tomography can identify pancreatic masses or hepatic disease. ## Practical Implementation Steps ### Step 1: Confirm the Glucose Abnormality Obtain a blood sample and measure glucose using a laboratory analyzer. If the point-of-care glucometer shows an abnormal result, repeat the measurement with a laboratory sample. Record the time of the sample and the patient's clinical status. ### Step 2: Assess the Clinical Context Evaluate the patient for signs of diabetes mellitus, including polyuria, polydipsia, weight loss, and cataracts. Evaluate for signs of hypoglycemia, including weakness, seizures, and collapse. Determine whether the signs are acute or chronic and whether they correlate with meals or activity. ### Step 3: Perform Baseline Laboratory Testing Submit a complete blood count, serum biochemistry profile, and urinalysis. The biochemistry profile should include glucose, liver enzymes, albumin, and electrolytes. The urinalysis should include glucose, ketones, and specific gravity. ### Step 4: Measure Fructosamine If the patient has hyperglycemia, measure fructosamine to determine whether the elevation is persistent. A normal fructosamine with an elevated glucose suggests stress hyperglycemia. An elevated fructosamine confirms diabetes mellitus. ### Step 5: Measure Insulin If the patient has hypoglycemia, measure insulin at the time of the low glucose. The sample should be collected when the glucose is below the reference range. A high insulin concentration with a low glucose indicates insulinoma or exogenous insulin. ### Step 6: Develop a Differential List Integrate the history, physical examination, and laboratory findings to develop a differential list. The list should include the most likely causes based on the patient's signalment and clinical presentation. ### Step 7: Initiate Treatment and Monitoring Treatment depends on the underlying cause. For diabetes mellitus, insulin therapy is the mainstay. For stress hyperglycemia, the underlying stressor should be addressed. For hypoglycemia, the cause must be identified and treated. ## Records and Measurements ### Glucose Log Maintain a glucose log for each patient. The log should include the date, time, glucose concentration, and the patient's clinical status. The log helps identify patterns and guide treatment adjustments. ### Fructosamine Trends Track fructosamine concentrations over time. A declining fructosamine indicates improved glycemic control. A rising fructosamine indicates inadequate control or the need for a change in therapy. ### Insulin and Glucose Pairs Record the paired insulin and glucose concentrations for hypoglycemic patients. The pair is essential for diagnosing insulinoma and for monitoring the response to treatment. ### Body Weight and Body Condition Record the body weight and body condition score at each visit. Weight loss is common in diabetes mellitus and insulinoma. Weight gain may indicate improved glycemic control. ## Common Failure Patterns ### Failure to Distinguish Stress Hyperglycemia from Diabetes A common error is to diagnose diabetes mellitus based on a single elevated glucose concentration in a stressed cat. The cat may have stress hyperglycemia, and the glucose may return to normal when the cat is calm. Fructosamine is the key test to distinguish these conditions. ### Failure to Confirm Hypoglycemia A single low glucose reading may be a laboratory error or a sample handling issue. The glucose should be confirmed with a repeat sample. The sample should be collected in a tube with a glycolytic inhibitor to prevent glucose consumption by red blood cells. ### Failure to Measure Insulin In a patient with hypoglycemia, the insulin concentration is essential for the differential. Without the insulin, the clinician cannot distinguish insulinoma from other causes of hypoglycemia. ### Failure to Consider Sepsis Sepsis can cause hypoglycemia because of increased glucose consumption and reduced hepatic glucose production. The patient may have fever, tachycardia, and hypotension. The glucose should be monitored closely in critically ill patients. ## Limitations and Caveats ### Point-of-Care Glucose Point-of-care glucometers can be inaccurate at very low or very high glucose concentrations. The results should be confirmed with a laboratory sample. The glucometer should be calibrated according to the manufacturer's instructions. ### Fructosamine in Cats Fructosamine is a useful test in cats, but it can be affected by hyperthyroidism and other conditions. The test should be interpreted in the context of the clinical picture. ### Insulin Assay Variability The insulin assay can vary between laboratories. The results should be interpreted with the reference range provided by the laboratory. The insulin-to-glucose ratio is not a substitute for clinical judgment. ### Species Differences Dogs and cats have different glucose metabolism and different reference ranges. The diagnostic approach should be tailored to the species. ## Welfare and Safety Context The World Organisation for Animal Health emphasizes the importance of animal health and welfare in veterinary practice. Glucose disorders can cause significant suffering if left untreated. Diabetes mellitus can lead to cataracts, neuropathy, and ketoacidosis. Hypoglycemia can cause seizures and brain damage. The American Veterinary Medical Association encourages pet owners to seek veterinary care for any animal with signs of illness. The American Animal Hospital Association recommends regular preventive care examinations, which can identify glucose disorders early. ## Professional Escalation Criteria ### Urgent Escalation The patient should be referred to an emergency facility if the animal has seizures, collapse, or severe lethargy. The animal may have severe hypoglycemia or diabetic ketoacidosis. The glucose should be measured immediately, and the animal should be stabilized. ### Routine Escalation The patient should be referred to a specialist if the diagnosis is unclear or if the patient does not respond to treatment. A veterinary internal medicine specialist can perform advanced imaging and endocrine testing. ### Owner Education The owner should be educated about the signs of hypoglycemia and hyperglycemia. The owner should know when to seek emergency care and how to monitor the animal at home. ## Building a Structured Glucose Monitoring Plan for Home and Hospital A glucose abnormality diagnosis is only the beginning of patient management. The gap between identifying hyperglycemia or hypoglycemia and achieving stable control often lies in the absence of a structured monitoring plan. Clinicians frequently encounter cases where the initial diagnostic workup is correct, but the subsequent management fails because glucose measurements are sporadic, uncoordinated with meals or insulin administration, or not recorded in a way that reveals patterns. A structured monitoring protocol that integrates home and hospital measurements provides the framework needed to adjust therapy, detect complications early, and communicate effectively with owners. ### Why a Structured Monitoring Plan Matters The clinical value of a glucose measurement depends entirely on its context. A single reading of 250 mg/dL in a diabetic dog tells the clinician little about whether the insulin dose is appropriate, whether the glucose is trending upward or downward, or whether the animal is experiencing dangerous fluctuations. Similarly, a single low glucose reading in a cat with suspected insulinoma does not establish the diagnosis without a paired insulin sample and a documented history of clinical signs. A structured monitoring plan addresses these limitations by defining when to measure glucose, how to interpret the results, and what actions to take based on those results. The plan should be tailored to the individual patient, the underlying condition, and the owner's ability to perform measurements at home. The American Animal Hospital Association emphasizes that preventive care and chronic disease management require a partnership between the veterinary team and the owner, with clear communication about monitoring expectations and treatment goals. ### Components of a Glucose Monitoring Protocol A complete monitoring protocol includes several components that work together to provide a full picture of the patient's glucose status. These components are the glucose curve, the serial glucose log, the fructosamine trend, the clinical sign diary, and the insulin adjustment algorithm. Each component serves a distinct purpose, and the protocol is most effective when all components are used together. #### The Glucose Curve The glucose curve is the cornerstone of insulin dose adjustment in diabetic dogs and cats. A glucose curve involves measuring blood glucose every two to four hours over a 12 to 24 hour period, typically starting before the morning insulin injection and continuing through the duration of insulin action. The curve reveals the peak glucose concentration, the nadir or lowest glucose concentration, the time to nadir, and the duration of insulin effect. The glucose curve is essential for determining whether the insulin dose is appropriate. If the glucose nadir is too low, the insulin dose may be excessive. If the glucose remains elevated throughout the curve, the insulin dose may be insufficient. If the glucose drops rapidly and then rises quickly, the insulin may be acting too quickly or the duration of action may be too short. The glucose curve should be performed in the hospital or at home with a validated glucometer. The owner should be instructed to feed the animal and administer insulin exactly as they do at home. The glucose measurements should be recorded on a curve sheet that includes the time, the glucose concentration, and any clinical signs observed. #### The Glucose Log The glucose log is a daily record of glucose measurements taken at specific times. The log is used to track trends over time and to identify patterns that may not be apparent from a single glucose curve. The log should include the date, the time of each measurement, the glucose concentration, the insulin dose, the time of feeding, and any clinical signs. The glucose log is particularly useful for identifying the Somogyi effect, which is a rebound hyperglycemia that occurs after an episode of hypoglycemia. The Somogyi effect can be difficult to detect without a log because the hyperglycemia may be mistaken for inadequate insulin dosing. A log that shows a pattern of low glucose followed by high glucose suggests the Somogyi effect and indicates that the insulin dose should be reduced instead of increased. #### The Fructosamine Trend Fructosamine is a glycated protein that reflects the average glucose concentration over the preceding two to three weeks. Fructosamine is measured at the time of diagnosis and then at regular intervals during treatment. The trend in fructosamine is more useful than a single measurement because it shows whether the average glucose is improving, stable, or worsening. The fructosamine trend is particularly useful in cats, where stress hyperglycemia can complicate the interpretation of a single glucose measurement. A cat with a normal fructosamine and an elevated glucose is likely experiencing stress hyperglycemia. A cat with an elevated fructosamine and an elevated glucose has persistent hyperglycemia and requires insulin therapy. The fructosamine trend should be interpreted in the context of the clinical picture. A declining fructosamine indicates improved glycemic control, but the glucose may still be too low at certain times of the day. A rising fructosamine indicates inadequate control, but the glucose may be fluctuating widely. #### The Clinical Sign Diary The clinical sign diary is a record of the owner's observations of the animal's behavior, appetite, thirst, urination, and energy level. The diary is essential for correlating the glucose measurements with the clinical signs. A dog with a glucose of 200 mg/dL may be clinically normal, while a dog with a glucose of 200 mg/dL and polyuria and polydipsia may require an insulin adjustment. The clinical sign diary is also useful for detecting hypoglycemia. The owner should be instructed to record any signs of weakness, lethargy, ataxia, tremors, collapse, or seizures. The signs should be correlated with the time of the last insulin injection and the last meal. #### The Insulin Adjustment Log The insulin adjustment log is a record of the insulin dose, the time of administration, and the reason for any change in the dose. The log is essential for ensuring that the insulin dose is adjusted safely and systematically. The log should include the date, the insulin dose, the time of administration, the glucose measurements, and the clinical signs. The insulin adjustment log is used to track the response to insulin therapy. The log should be reviewed at each recheck visit, and the insulin dose should be adjusted based on the glucose curve, the glucose log, and the clinical sign diary. ### Implementing the Protocol in Practice The implementation of a structured glucose monitoring protocol requires a team approach. The veterinarian is responsible for the initial diagnosis, the development of the monitoring plan, and the interpretation of the results. The veterinary technician or nurse is responsible for the education of the owner, the performance of the glucose curve, and the maintenance of the records. The owner is responsible for the daily glucose measurements, the clinical sign diary, and the administration of insulin. #### Step 1: Establish the Baseline The first step in implementing the protocol is to establish a baseline. The baseline includes the initial glucose measurements, the Fructosamine concentration, the clinical signs, and the body weight. The baseline is used to determine the initial insulin dose and to set the target glucose range. The target glucose range for a diabetic dog or cat is typically between 100 and 250 mg/dL. The target range is not the same for every patient. The target range should be individualized based on the patient's clinical signs, the risk of hypoglycemia, and the owner's ability to monitor the glucose. #### Step 2: Educate the Owner The owner must be educated about the monitoring protocol before the patient is discharged. The education should include the use of the glucometer, the collection of the blood sample, the recording of the glucose measurements, and the recognition of the clinical signs of hypoglycemia and hyperglycemia. The owner should be instructed to measure the glucose at specific times, such as before the morning insulin injection and before the evening meal. The owner should also be instructed to measure the glucose whenever the animal shows signs of hypoglycemia or hyperglycemia. #### Step 3: Perform the Glucose Curve The glucose curve should be performed within the first week of insulin therapy. The curve is used to determine the duration of insulin action and the glucose nadir. The curve should be repeated at each recheck examination or when the clinical signs suggest a change in the glucose control. #### Step 4: Review the Records The records should be reviewed at each recheck examination. The review should include the glucose log, the clinical sign diary, the insulin adjustment log, and the Fructosamine trend. The review should identify any patterns that require an adjustment in the insulin dose or the monitoring plan. #### Step 5: Adjust the Insulin Dose The insulin dose should be adjusted based on the glucose curve and the glucose log. The dose should be changed by no more than 10 to 25 percent at a time. The dose should be increased if the glucose is consistently above the target range, and the dose should be decreased if the glucose is consistently below the target range or if the animal shows signs of hypoglycemia. ### Records and Measurements for the Monitoring Protocol The monitoring protocol requires a set of records that are maintained by the owner and the veterinary team. The records should be reviewed at each recheck and updated as the treatment changes. #### The Home Glucose Log The home glucose log is a daily record of the glucose measurements. The log should include the date, the time, the glucose concentration, the insulin dose, the time of feeding, and the clinical signs. The log should be brought to each recheck examination. #### The Glucose Curve Sheet The glucose curve sheet is a record of the glucose measurements performed during the curve. The sheet should include the time of each measurement, the glucose concentration, and the clinical signs. The sheet should be used to determine the glucose nadir and the duration of insulin action. #### The Fructosamine Record The Fructosamine record is a list of the Fructosamine concentrations measured at each recheck. The record should include the date, the Fructosamine concentration, and the glucose concentration at the time of the measurement. The record is used to track the trend in the average glucose. #### The Clinical Sign Diary The clinical sign diary is a record of the owner's observations. The diary should include the date, the time, the sign, and the glucose concentration if measured. The diary is used to correlate the clinical signs with the glucose measurements. #### The Insulin Adjustment Log The insulin adjustment log is a record of the insulin dose and any changes. The log should include the date, the dose, the time of administration, and the reason for the change. The log is used to ensure that the insulin dose is adjusted safely and systematically. ### Common Failure Patterns in Glucose Monitoring The most common failure pattern in glucose monitoring is the reliance on a single glucose measurement. A single measurement does not provide the information needed to adjust the insulin dose or to identify the cause of the glucose abnormality. The glucose must be measured at multiple times to identify the pattern. Another common failure pattern is the failure to record the glucose measurements. The glucose measurements are only useful if they are recorded and reviewed. The owner should be instructed to record the measurements in a log and to bring the log to each recheck. A third common failure pattern is the failure to adjust the insulin dose based on the glucose curve. The insulin dose should be adjusted based on the glucose curve, not on a single glucose measurement. The dose should be adjusted by no more than 10 to 25 percent at a time. A fourth common failure pattern is the failure to recognize the Somogyi effect. The Somogyi effect is a rebound hyperglycemia that occurs after an episode of hypoglycemia. The Somogyi effect can be mistaken for inadequate insulin dosing, and the insulin dose may be increased when it should be decreased. A fifth common failure pattern is the failure to consider the owner's ability to monitor the glucose. The owner may not be able to measure the glucose at home, or the owner may not be able to recognize the signs of hypoglycemia. The monitoring plan should be tailored to the owner's ability and the patient's needs. ### Troubleshooting the Monitoring Protocol When the glucose control is not improving, the clinician should review the monitoring protocol to identify the cause. The review should include the glucose curve, the glucose log, the Fructosamine trend, and the clinical sign diary. #### The Glucose Is Consistently High If the glucose is consistently high, the insulin dose may be insufficient. The insulin dose should be increased by 10 to 25 percent. The glucose curve should be repeated to determine the new glucose nadir and the duration of insulin action. #### The Glucose Is Consistently Low If the glucose is consistently low, the insulin dose may be excessive. The insulin dose should be decreased by 10 to 25 percent. The glucose should be monitored closely for signs of hypoglycemia. #### The Glucose Fluctuates Widely If the glucose fluctuates widely, the insulin may be acting too quickly or the duration of action may be too short. The insulin type or the frequency of administration may need to be changed. The glucose curve should be repeated to identify the pattern. #### The Glucose Is High in the Morning and Low in the Evening If the glucose is high in the morning and low in the evening, the insulin may be wearing off before the next dose. The insulin dose may need to be increased, or the frequency of administration may need to be increased. #### The Glucose Is Low in the Morning and High in the Evening If the glucose is low in the morning and high in the evening, the insulin may be acting too strongly at the time of the morning dose. The insulin dose may need to be decreased, or the timing of the dose may need to be changed. ### The Role of the Veterinary Team The veterinary team is responsible for the development and the implementation of the monitoring protocol. The veterinarian is responsible for the initial diagnosis, the development of the monitoring plan, and the interpretation of the results. The veterinary technician or nurse is responsible for the education of the owner, the performance of the glucose curve, and the maintenance of the records. The veterinary team should communicate with the owner at each recheck. The team should review the glucose log, the clinical sign diary, and the Fructosamine trend. The team should adjust the insulin dose based on the glucose curve and the glucose log. The veterinary team should also provide the owner with the resources needed to monitor the glucose at home. The owner should be provided with a glucose meter, a log, and the instructions for the use of the meter. The owner should also be provided with the contact information for the veterinary team in case of an emergency. ### Owner Education and Engagement The success of the monitoring protocol depends on the owner's engagement. The owner must be educated about the importance of the glucose monitoring and the signs of hypoglycemia and hyperglycemia. The owner must also be trained in the use of the glucose meter and the recording of the glucose measurements. The owner should be encouraged to ask questions and to report any concerns. The owner should also be encouraged to bring the glucose log and the clinical sign diary to each recheck. The owner should be informed about the signs of hypoglycemia and the emergency treatment for hypoglycemia. The American Veterinary Medical Association encourages pet owners to seek veterinary care for any animal with signs of illness. The owner should be informed that the glucose monitoring is a lifelong process and that the treatment plan may need to be adjusted over time. ### Limitations and Caveats of the Monitoring Protocol The monitoring protocol has several limitations. The glucose curve is a snapshot of the glucose over a 12 to 24 hour period, and the curve may not reflect the glucose on other days. The glucose log is only as accurate as the owner's measurements. The Fructosamine trend is a measure of the average glucose, but it does not identify the glucose fluctuations. The glucose meter may be inaccurate at very low or very high glucose concentrations. The glucose meter should be calibrated according to the manufacturer's instructions. The glucose measurements should be confirmed with a laboratory sample if the glucose is very low or very high. The monitoring protocol is not a substitute for the clinical judgment of the veterinarian. The protocol provides the data, but the veterinarian must interpret the data and make the treatment decisions. ### Welfare and Safety Context The World Organisation for Animal Health emphasizes the importance of animal health and welfare in veterinary practice. The glucose monitoring protocol is a tool for the welfare of the animal. The protocol helps to prevent the complications of diabetes mellitus, including hypoglycemia, ketoacidosis, and the long-term complications of hyperglycemia. The American Veterinary Medical Association encourages the pet owners to seek veterinary care for any animal with signs of illness. The American Animal Hospital Association recommends the regular preventive care examinations, which can identify the glucose disorders early. The monitoring protocol should be implemented with the welfare of the animal in mind. The glucose measurements should be performed with the least amount of stress to the animal. The owner should be trained in the gentle handling of the animal during the glucose measurement. The glucose should be monitored closely in the animals that are at risk for hypoglycemia, including the animals with the insulinoma, the sepsis, and the hepatic disease. ### Professional Escalation Criteria The monitoring protocol should include the criteria for the escalation of the care. The owner should be instructed to contact the veterinary team if the animal shows the signs of hypoglycemia, such as the weakness, the lethargy, the ataxia, the tremors, the collapse, or the seizures. The owner should also be instructed to contact the veterinary team if the glucose is consistently below the target range or if the glucose is consistently above the target range. The animal should be referred to the emergency facility if the animal has the seizures, the collapse, or the severe lethargy. The animal may have the severe hypoglycemia or the diabetic ketoacidosis. The glucose should be measured immediately, and the animal should be stabilized. The animal should be referred to the specialist if the diagnosis is unclear or if the animal does not respond to the treatment. The veterinary internal medicine specialist can perform the advanced imaging and the endocrine testing. ## Frequently Asked Questions ### What is the difference between stress hyperglycemia and diabetes mellitus in cats? Stress hyperglycemia is a transient elevation in glucose caused by the release of epinephrine during handling or hospitalization. Diabetes mellitus is a persistent elevation caused by insulin deficiency or resistance. Fructosamine is the key test to distinguish these conditions. ### How is fructosamine used in the diagnosis of diabetes mellitus? Fructosamine reflects the average glucose concentration over the preceding two to three weeks. A normal fructosamine with an elevated glucose suggests stress hyperglycemia. An elevated fructosamine confirms diabetes mellitus. ### What causes hypoglycemia in dogs and cats? Hypoglycemia can be caused by insulinoma, sepsis, hepatic disease, hypoadrenaline, starvation, or exogenous insulin administration. The cause is determined by the history, physical examination, and laboratory testing. ### How is insulinoma diagnosed in dogs? Insulinoma is diagnosed by measuring a paired insulin and glucose concentration. A high insulin concentration with a low glucose concentration is diagnostic. Imaging with abdominal ultrasound or computed tomography can identify the pancreatic mass. ### What is the treatment for hypoglycemia in dogs and cats? The treatment for hypoglycemia depends on the underlying cause. For insulinoma, surgical removal of the tumor is the treatment of choice. For sepsis, the infection is treated. For hepatic disease, the underlying cause is addressed. ### How often should I monitor glucose in a diabetic dog or cat? The frequency of glucose monitoring depends on the stability of the patient. A glucose curve is performed initially to determine the insulin dose. The glucose should be monitored periodically to ensure adequate control. ### Can stress hyperglycemia be treated? Stress hyperglycemia is treated by addressing the underlying stressor. The glucose will return to normal when the stress is resolved. No specific treatment is needed for the glucose elevation itself. ### What is the prognosis for a dog with insulinoma? The prognosis for a dog with insulinoma depends on the stage of the disease. Surgical removal of the tumor can provide a good prognosis. The tumor can recur, and the patient may require ongoing management. ## Using the Evidence | Source | Best use in this topic | Important limitation | |---|---|---| | [Pet Care](https://www.avma.org/resources-tools/pet-owners) | official guidance | Check the linked page for current local requirements | | [AAHA Guidelines](https://www.aaha.org/resources) | official guidance | Check the linked page for current local requirements | | [Global Guidelines](https://wsava.org/global-guidelines) | official guidance | Check the linked page for current local requirements | ## Related Veterinary Guides - [Diagnostic Approach to Acute Abdomen in Dogs and Cats](/knowledge/veterinary-medicine/veterinary-surgery/diagnostic-approach-acute-abdomen-dogs-cats) - [Thoracic Radiograph Patterns in Dogs: Differential Diagnosis and Clinical Approach](/knowledge/veterinary-medicine/diagnostic-imaging/thoracic-radiograph-patterns-dogs-differential-diagnosis-clinical-approach) - [Thrombocytopenia in Dogs and Cats: Diagnostic Approach and Differential Prioritization](/knowledge/veterinary-medicine/clinical-pathology/thrombocytopenia-dogs-cats-diagnostic) - [Differential Diagnosis in Pathology: A Structured Approach](/knowledge/veterinary-medicine/veterinary-pathology-microbiology/differential-diagnosis-in-pathology-a-structured-approach) - [Canine Hepatomegaly: Differential Diagnosis and Diagnostic Approach](/knowledge/veterinary-medicine/clinical-methods/canine-hepatomegaly-differential-diagnosis-diagnostic-approach) ## References and Further Reading - [Pet Care](https://www.avma.org/resources-tools/pet-owners). American Veterinary Medical Association. - [AAHA Guidelines](https://www.aaha.org/resources). American Animal Hospital Association. - [Global Guidelines](https://wsava.org/global-guidelines). World Small Animal Veterinary Association. - [Merck Veterinary Manual](https://www.merckvetmanual.com/). Merck Veterinary Manual. - [Cornell University College of Veterinary Medicine](https://www.vet.cornell.edu/). Cornell University. - [Animal Health and Welfare](https://www.woah.org/en/what-we-do/animal-health-and-welfare). World Organisation for Animal Health. - [Abstracts from the 3rd International Genomic Medicine Conference (3rd IGMC 2015) : Jeddah, Kingdom of Saudi Arabia. 30 November - 3 December 2015.](https://pubmed.ncbi.nlm.nih.gov/27454254). BMC genomics, 2016. - [Analysis of blood biochemistry and non-targeted metabolomics of endometritis in dairy cows.](https://pubmed.ncbi.nlm.nih.gov/38564886). Animal reproduction science, 2024. - [Methamphetamine intoxication in a dog: case report.](https://pubmed.ncbi.nlm.nih.gov/24962469). BMC veterinary research, 2014. - [Inaccurate point-of-care blood glucose measurement in a dog with secondary erythrocytosis.](https://pubmed.ncbi.nlm.nih.gov/31840932). Journal of veterinary emergency and critical care (San Antonio, Tex. : 2001), 2020. - [Haematological and Serum Biochemical Reference Intervals for Nigerian White Fulani Neonatal Calves.](https://pubmed.ncbi.nlm.nih.gov/40156808). Nigerian journal of physiological sciences : official publication of the Physiological Society of Nigeria, 2024. > This article is educational and is not a substitute for veterinary diagnosis or treatment. Contact a veterinarian for advice about an individual animal.