Monitoring blood sugar in patients with diabetes mellitus

Author: Thomas Schermerhorn, VMD, DACVIM (Saim), Kansas State University

A round glucose minting device for measuring the interstitial glucose level is attached to the shaved skin of an animal.

For every patient with diabetes mellitus (DM), a long -term surveillance strategy should be developed that is medically well -founded, practical and effective. A close relationship between the vet and animal owners is crucial for success because the owner takes over daily care and carries out most routine monitoring. Pet owners should be able to recognize early signs of problems in DM management and pass on their observations to the practice team. Regular clinical examinations and laboratory tests are also of central importance and offer a good opportunity to discuss progress, analyze problems and to assess the quality of life. The restoration and maintenance of the patient's quality of life is of the utmost importance¹ ² and should be a central goal of every surveillance strategy.

Optimal blood sugar control requires suitable insulin therapy to control hyperglycemia and to avoid hypoglycemia and other complications. Various laboratory tests and clinical aids are available that are suitable for monitoring³ ⁴; However, no method or combination has so far been clearly identified as clinically superior. Therefore, the monitoring program should be practical and adapted to the individual needs of the patient as well as the skills, circumstances and therapy goals of the owner. Recommendations for DM monitoring in dogs and cats are usually based on expert opinions and practical experience; There are also published consensus guidelines. The goal of eliminating clinical signs of DM can be reached for most patients - but there are various strategies that can be used to achieve acceptable blood sugar levels. The interventions should be common enough to be effective, but not so often that they become impractical or stressful for the owner.

Monitoring methods

The monitoring of DM comprises several direct and indirect methods for evaluating blood sugar control (see Table 1). Use direct methods to determine quantitative methods for determining blood sugar (e.g. random or individual measurements, blood sugar curves, interstitial glucose monitoring [IGM]). Indirect methods evaluate subjective (e.g. clinical symptoms, physical examination) or lenses (e.g. measurement of HBA1C or fructosamine) parameters that are influenced by blood sugar levels, but do not measure glucose directly. Effective DM monitoring should combine different methods- each has its advantages and disadvantages (see Table 2).

Table 1: Monitoring methods for diabetes mellitus

Table 2: Advantages and disadvantages of the surveillance methods

Assessment of clinical symptoms

Polydipsia (increased drinking) and polyuria (increased urination) are common clinical signs in DM, directly caused by hyperglycemia. These lead to osmotic diuresis and glucosuria when the kidney threshold for glucose (about 200 mg/dl in dogs, 250 mg/dl in cats ) is exceeded.

Appetite, body weight and physical condition also provide information on blood sugar control. While the appetite is usually preserved, weight and fitness are often reduced at the time of the diagnosis - improvement through therapy is expected. In the absence of weight gain or loss despite therapy, inadequate BZ control should be suspected.

Advantages of symptom monitoring:

1. BZ disorders can be recognized indirectly: If symptoms remain under treatment or occur again, the persistent hyperglycaemia indicates.
2. Positive correlation: Studies show that the assessment of the symptoms by pet owners often correlate well with objective measurements such as fructosamine.

Urine monitoring

The urine examination on glucose and ketones in DM patients serve to identify changes in the state of health at an early stage-ideally before clinical symptoms occur. Sudden changes in the extent of glucosuria or the occurrence of ketoneuria can indicate a disorder of blood sugar control.

However, such changes are often only evident in practice after there are already clinical symptoms. Further disadvantages of urine monitoring are the difficult sample acquisition, which can lead to poor compliance.

Conclusion: not recommended for routine DM monitoring , but can be used in certain situations-always in connection with others⁶.

Glyced proteins

Glucose binds non-enzymatic proteins in the blood-so-called glycation. The concentration of these glyca -talented proteins increases with the blood sugar level and, in retrospect, provides information on average glycemia over a certain period of time.

The most important glycaica proteins in veterinary medicine are:

• Fructuamine
• HBA1C (glycated hemoglobin)

Fructuamine

• Mainly consists of glycosylated albumin⁷
• Provides information about the average BZ of the past 2 weeks , according to the service life of serum albumin
• Often used in veterinary practice

HBA1C

• Reflects the average blood sugar over 70 days (cat) or 120 days (dog)
• Is used intensively in human medicine, but is also increasingly being used in veterinary medicine
• Commercial tests for dogs and cats are available
• Advantage: smaller amount of blood required
• Disadvantage: reacts less sensitive to short -term changes

Both markers should fall with successful insulin therapy. Studies show advantages of HBA1C, especially for dogs¹⁰–¹³.

Restrictions on protein measurement

Medical conditions that influence the concentration of the underlying proteins also influence the glycated form:

• Fructosamine drops in hypoproteinemia, hypoalbuminemia, hyperlipidemia or renal insufficiency⁹
• In cats, hyperthyroidism can reduce values ​​by increased protein turnover values
• HBA1C is also influenced by anemia or changed erythrocyte sales³

Blood sugar measurement

The direct measurement of blood sugar (BZ) is the gold standard when it comes to the immediate and precise assessment of glycemia.

It allows an exact assessment of the insulin effect:

• Start, level and duration of action
• Effectiveness of insulin therapy

The classic method is the blood sugar curve (BZK) interstitial glucose measurement (IGM) is increasingly being used.

Individual measurements ("Spot-BZ") have little meaning and should not be used to control the insulin dosage.

The blood sugar curve (BZK)

This method includes the measurement of blood sugar every 1–2 hours over a defined period - usually 12 hours, occasionally longer. The values ​​are shown graphically, usually with the help of a portable glucometer.

Blood samples (venous or capillary) are taken manually with a needle or lancet - typically from small veins, ear or paw. Depending on how often it is measured, the number of data points varies.

The BZK is usually carried out in practice, but some veterinarians: Inside, trained owners recommend that they also make them at home. A detailed overview of the implementation and interpretation of a BZK is available¹⁴.

Interstitial glucose measurement (IGM)

The IGM measures the glucose level in the interstitial liquid - i.e. in the tissue - over several days or weeks ¹⁵.

Two variants:

1. Continuous glucose measurement (CGM)
   automatic real-time measurement with integration in insulin pumps possible.
2. Flash glucose measurement (FGM)
   only shows values ​​when “reading” through the reader.

The glucose value in the tissue differs from that in the blood-with a time offset (LAG-TIME), especially in the case of fast BZ changes¹⁶.

This can lead to rapid hypoglycaemia not being recognized in time. Nevertheless, the method offers valuable knowledge - especially for long -term monitoring .

Advantages for home

The measurement by pet owners: Inside is a practical way to continuously gain data¹⁷ ¹⁸. In studies , around 85 % of the owners to successfully carry out long -term home monitoring with frequent blood sample on the inside.

FGM systems are particularly well received:

• No daily calibration necessary
• Easy data acquisition and analysis
• Ideal for individual therapy adjustment

The goal is not only to disappear the symptoms, but also to achieve defined blood sugar areas.

Interstitial glucose measurement systems

IGM has been used in veterinary medicine for over 15 years. Different systems have proven to be useful in dogs and cats.

Modern devices are:

• user -friendly
• Well suited for home use

A newly developed FGM system shows promising results in studies-although the previous literature is limited.

How does it work?

• A sensor is introduced into the skin with an insertion aid and attached there (see Fig. 1 )
• The sensor measures glucose value every minute
• Saved data is wirelessly to a reader

Figure 1

A round sensor of a flash device is attached to the shaved skin of a diabetic cat. The application aid provided by the manufacturer enables easy placement. The sensor (35 mm diameter × 5 mm height) contains a flexible filament tip, which continuously measures the BZ in the tissue. The data is sent to a handheld device via radio.

Interventional vs. dose -related monitoring

A distinction is made between two approaches to BZ monitoring:

1. Dose monitoring
   → Assessment of the overall effect of a certain insulin dose
2. Interventional surveillance
   → Decision whether immediate correction of the current blood sugar value is necessary

Although both are carried out with the same techniques, they differ fundamentally in the application (see Fig. 2 ).

Practical tip

In veterinary medicine, the BZ monitoring usually serves to assess the long-term assessment of the insulin effect. Interventional surveillance should be used with caution - especially with unsafe animal owners.

Studies show that strict control does not necessarily lead to better long -term results. On the contrary: the increased danger to hypoglycaemia can worsen the quality of life¹ ².

Some veterinarians: Therefore, recommend an adapted form:
BZ measurement right in front of the insulin injection in order to adapt the dose if necessary.

Figure 2

The graphic shows two different BZ courses according to insulin:

• Red : Dose -related strategy - there is no adaptation when increasing again
• Gray : Interventional strategy - another injection reduces the BZ into the target area again
• Black : Both strategies run the same later

Interpretation of the blood sugar curve (BZK)

Regardless of the method used to create a BZ curve, a comparison with other parameters is always recommended. B. clinical symptoms or long -term markers such as fructosamine or HBA1C.

The BZK is particularly helpful to recognize hypoglycaemia These often indicate an overdose of insulin and make dose reduction necessary.

Persistent hyperglycaemia also be uncovered by curve analysis. The causes are varied:

• Incorrect administration of insulin
• Lack of compliance
• Inadequate dosage
• Insulin resistance

Biological variability

A central problem with the interpretation of BZ curves is the biological fluctuation of the insulin effect. Even under controlled conditions, the insulin effect in humans can vary by 15–50 % ²¹.

In veterinary medicine, this variability is usually even more pronounced ²². It can be influenced by many factors:

• Stress, fear
• Movement
• Body temperature
• Conservation diseases (e.g. infections or hormonal disorders)

A study in dogs showed that even with the same insulin dose, the parameters of the BZ curve (e.g. minima, maxima and time of the low value) differed significantly from day to day.

In almost 45 % of cases, the curves even led to opposing therapy recommendations -once to the dose increase, another time to reduce.

Conclusion

🔍 There is no individual method or combination of methods that are demonstrably superior in diabetic dogs or cats. An too strong focus on just one procedure is not recommended.

✅ Effective monitoring should always combine different methods - ideally those that capture different aspects of blood sugar control.

🧩 A flexible, practical surveillance concept that provides both objective information and fits the possibilities and goals of the owner can:

• integrate the pet owner as an active part of the therapy
• improve compliance
• and strengthen the veterinarian-animal-keeper relationship

Summary: Monitoring the blood sugar in pets with diabetes mellitus

The monitoring of blood sugar is a central element in the management of diabetes mellitus in dogs and cats. It not only enables the control of insulin therapy, but also significantly improves the quality of life of the animal. Any monitoring of the blood sugar aims to avoid dangerous hypo or hyperglycaemia and to secure metabolic stability in the long term.

The focus is on an individually adapted monitoring of the blood sugar , which is based on the needs of the animal and the possibilities of animal owners. There are various methods for monitoring blood sugar , including direct measurements such as classic blood sugar curve or modern systems such as interstitial glucose measurement. Indirect procedures such as measuring fructosamine or HBA1C offer a longer -term perspective on monitoring blood sugar .

The correct monitoring of blood sugar should include various data sources: clinical symptoms, laboratory parameters and technical measurements. Only through this combination is a holistic monitoring of the blood sugar , which allows both short -term and long -term therapy controls.

The integration of the pet owners is particularly important. Your participation in monitoring the blood sugar in the home environment-for example through flash glucose measurements-promotes compliance and provides valuable information for veterinary care. The observation of changes in behavior such as increased drinking, changing appetite or weight loss is also part of the monitoring of blood sugar .

The choice of the suitable method for monitoring blood sugar depends on many factors: age of the animal, comorbidities, susceptibility to stress and technical possibilities. In some cases, close monitoring of blood sugar from the veterinarian may also be necessary, especially when therapy begins or unstable metabolism.

A one -time measurement is not sufficient - rather, the monitoring of the blood sugar be continuously and dynamically. This is the only way to make therapy decisions well. Especially when changing insulin preparations, the close monitoring of blood sugar crucial.

Although no single method is sufficient for yourself, a versatile monitoring of blood sugar the chance of successful treatment. Studies show that structured monitoring of blood sugar can significantly reduce the clinical symptoms, but also the complication rates.

monitoring of blood sugar allows early detection of insulin resistance, side effects or errors in the injection. Therefore, every veterinary practice should establish clear protocols to monitor blood sugar and communicate with the owners.

monitoring of blood sugar also plays a major role in terms of long -term markers : Fructosamine and HBA1C are particularly useful if daily measurements are not feasible or the values ​​fluctuate sharply. monitoring blood sugar offers additional security.

In the end, a structured, regular and practical monitoring of blood sugar significantly to improve the quality of life and life expectancy of a diabetic animal. The monitoring of the blood sugar is not only a diagnostic instrument, but also a therapeutic tool that significantly influences the success of the entire treatment.

Animal owners should be trained well by veterinarian: so that the monitoring of blood sugar can also be monitored safely and reliably at home. Only if everyone involved works together will the monitoring of blood sugar become an effective and life -saving part of the diabetes treatment in pets.

In addition to the pure glucose measurement, the monitoring of the blood sugar also include accompanying parameters. This includes, for example, weight development, feed intake, water consumption and behavior. Such observations can indicate a change in the course of blood sugar at an early stage and provide important information as to whether the blood sugar is required or an adaptation of the therapy is required.

An increasingly important aspect in monitoring blood sugar is the use of digital aids. Modern technologies such as mobile apps, cloud -based evaluation tools or networked readers offer completely new possibilities of data acquisition and analysis. This digital monitoring of blood sugar not only makes an overview of long -term courses, but also enables more precise communication between animal owner and veterinarian.

Close, daily monitoring of blood sugar crucial, especially in the case of difficult to adjust patients. In such cases, a combination of continuous glucose measurement (CGM/FGM), regular fructosamine control and clinical assessment can offer the necessary security. A flexible adaptation of the insulin dose only ensures if the monitoring of blood sugar is reliable and up -to -date.

monitoring of the blood sugar be intensified in special life situations such as operations, pregnancy, travel or feed change In these phases, insulin requirements can fluctuate strongly, which requires precise and frequent control. Here the interstitial monitoring of blood sugar bring clear advantages because it delivers complete trend data without constantly stinging the animal.

For veterinarians: Inside, a well thought -out strategy for monitoring blood sugar also means avoiding complications proactively. Early detection of therapy gliders, insulin resistance or diabetic complications such as neuropathy or cataract protects the animal and strengthens the trust of the animal owners. The monitoring of blood sugar becomes an active contribution to prevention.

Last but not least, structured monitoring of blood sugar also supports the animal owners psychologically. Many owners initially feel overwhelmed by the diagnosis of "diabetes mellitus". An understandably explained, clearly structured monitoring of blood sugar gives security, orientation and the feeling of being able to actively contribute to the good of the animal. It is therefore not only a diagnostic tool, but also a key to more animal-people.

monitoring the blood sugar is an indispensable part of every successful diabetes treatment. It is individually adaptable, versatile and more comfortable than ever with new technologies. Whether classic in practice, integrated into everyday life at home or digitally - the monitoring of the blood sugar opens veterinarian: inside and owner: Inside numerous ways to sustainably improve the lives of diabetic animals.

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