Most owners can learn to check blood glucose levels at home. Readings taken in a familiar environment are often more accurate than clinic values (since dogs are less stressed), and over time this can save a lot of money compared with repeated in-clinic testing.
Monitoring is how we check that your dog’s diabetes management plan is working day to day. Sometimes this just means keeping an eye on simple things at home, like how much they’re eating, drinking, and weighing, and whether their energy levels feel “normal.” Other times it involves more detailed tests, such as blood glucose curves or fructosamine, to get a clearer picture of how insulin is working in the body. It’s also important to watch for signs of other illnesses, since infections, pain, or hormonal changes can all affect how your dog’s body responds to insulin.
Many owners learn how to do blood glucose testing at home, which not only helps save on costs but also provides more accurate results than clinic-based measurements, since dogs are less stressed in their normal environment.
The key is to find a balance between gathering enough information and keeping the process practical for you and your dog.
Monitoring is about confirming that your dog’s clinical signs are controlled with their current care plan and ensuring they are not experiencing episodes of low blood sugar. It also helps catch early changes that could signal trouble, allowing adjustments before problems become serious. Monitoring can range from simple, low-cost checks to more detailed tests, and the best approach is the one that’s practical for you while keeping your dog safe and well.
Unlike human diabetes, where blood sugar may be checked many times a day, most dogs can be managed with a far less intensive monitoring plan. The following sections outline the main options you and your vet can consider.
Most diabetic dogs do best on a consistent diet — eating the same type and amount of food at the same times each day. Keep an eye out for changes in appetite. A sudden increase or decrease in how much your dog eats can signal that their diabetes is not well controlled, or that another illness is developing. If your dog regularly leaves food behind or seems hungrier than usual, let your vet know.
An easy way to monitor how well your dog is eating is to keep track of how much of their meal they finish (0% to 100%) and how long it takes them to do so. Most diabetic dogs should finish their entire meal (100%) within about 15–20 minutes.
Free
Healthy, non-diabetic dogs typically drink around 50–60 mL of water per kilogram of body weight per day. This can vary depending on their diet, weather, and activity levels. If they are drinking more than 100 mL per kilogram per day, it’s considered excessive.
Enter your dog's weight to get an estimate of about how much they should be drinking in a 24-hour period.
Even well-controlled diabetic dogs will usually drink a bit more than non-diabetic dogs. This is because it’s very difficult to keep their blood sugar levels within the normal range across the entire day. Rather than focusing too much on the absolute amount they drink, what really matters is watching for changes over time.
If you notice your dog heading to the water bowl more often than usual, or you find yourself refilling the bowl more frequently, this can be an early sign that their diabetes is slipping out of control and you should check in with your vet.
In single-pet households, a simple way to track how much your dog is drinking is to put the same amount of water in their bowl at the same time each day, then check how much is left right before you refill it the next day. This gives you a good estimate of their 24-hour water intake. To make it easier and more accurate, use a jug or measuring container with volume markings so you know exactly how much water you’re adding and how much is left over. Keep in mind it may not be perfectly precise if your dog splashes or spills while drinking.
Generally free, but may require purchase of a measuring cup
It’s completely normal for your dog’s weight to fluctuate slightly from day to day, just like it does in people. Small changes can happen because of hydration, when they last ate or toileted, or even minor differences between scales. What matters most is the overall trend over time.
If your goal is to maintain your dog’s current weight, it’s a concern if they consistently lose or gain more than 2% of their body weight per week, or if there’s a change of more than 5% at any single weekly weigh-in. This often means they’re not getting the right number of calories or their diabetes isn’t well controlled.
If your goal is weight loss or gain to reach an ideal body condition, a safe and healthy rate is about 1–2% of their body weight per week, though weight loss may be a little faster at first as they shed water weight.
n diabetic dogs, ongoing weight loss usually signals inadequate insulin, while excessive weight gain may mean too much insulin is being given. Importantly, even dogs that are losing weight can still experience dangerous hypoglycaemia if insulin doses are increased to try to compensate for a short duration of action.
Weigh your dog weekly, ideally at the same time of day using the same scale for consistency.
Generally free, but may require purchase of a scale
Testing your dog’s urine with dipsticks daily is a simple, low-cost, non-invasive way to monitor their diabetes. It’s normal to see some glucose in the urine and even the occasional day with ketones, since perfect control is rarely achieved. What matters most is the pattern: if glucose is always very high, always completely absent, or if ketones appear for more than three days in a row, it’s a signal to check in with your vet.
Keep in mind that urine results don’t reflect your dog’s status at the exact moment you test — they show what has been happening since the last time your dog urinated, as the bladder stores urine over several hours.
To collect a sample, slip a clean container (like a ladle, soup spoon, or urine cup) under your dog while they urinate, then dip the strip into the fresh urine. After the time listed on the packet (usually 30–60 seconds), compare the colour of the strip to the chart provided. For consistency, try to test at the same time of day, and record the results to share with your vet.
Urine dipsticks are widely available from most human pharmacies. A pack of 50 strips usually costs around NZD $10–$15 (about $0.20 to $0.30 per test).
Spot-testing involves taking a single blood glucose measurement at one point in time. It’s quick, inexpensive, and easy to perform, which makes it a useful tool in certain situations. Most often, we use spot tests to check for hypoglycaemia — either when a dog is showing clinical signs such as weakness, tremors, or disorientation, or when we want to make sure blood sugar is at a safe level before giving insulin with meals or around exercise.
If a low reading (less than 3.3–4.4 mmol/L (60–80 mg/dL)) is found in a dog that otherwise seems normal, it’s important to always confirm it with another measurement before making any changes to the insulin dose.
it’s equally important never to increase an insulin dose based on a single high blood glucose value. One reading doesn’t tell us when insulin is peaking, how long it lasts, or whether the overall dose is adequate. High results can also be misleading if they are caused by stress, or they may reflect what’s known as the Somogyi effect — a rebound where blood sugar first drops too low and then spikes very high after an insulin overdose. Without seeing the full pattern, this can be mistaken for poor control, leading to inappropriate increases in insulin when the opposite may actually be needed.
For that reason, spot-testing is best reserved as a safety check in specific situations and is usually not part of routine monitoring for diabetic dogs.
Measuring your dog’s blood glucose can feel daunting at first, but most owners find it becomes routine with a little practice. You’ll need a pet glucometer (such as the AlphaTrak 3), test strips, and a small lancet device to collect a drop of blood.
Prepare your supplies – Have the glucometer turned on, a fresh test strip loaded, and a lancet ready.
Choose a site – Common sites for collecting a drop of blood include:
The ear flap (pinna) – along the outer edge where the skin is thin and has good blood supply.
The lip – the hairless inner edge can work well in some dogs.
The paw pad – usually a side or back pad, not the main weight-bearing pad.
Collect a drop of blood – Use the lancet to make a quick prick at the chosen site, then gently squeeze to form a small bead of blood.
Apply to the test strip – Touch the edge of the test strip to the drop of blood; the glucometer will draw it in automatically.
Read and record – The glucometer will give you a reading within a few seconds. Write down the number, along with the time of day, when insulin was given, and whether your dog had eaten or exercised.
You can make blood glucose testing easier on your dog by warming the area first with a warm cloth to encourage blood flow, praising and rewarding them each time so they learn to tolerate the routine, and rotating between sites if one area becomes sore or bruised.
At home, the recommended device for pets is the AlphaTrak 3, which costs around NZD $210 for a starter pack. Ongoing costs are about NZD $25 for 50 lancets and NZD $90 for 50 glucose test strips, making the ongoing expense roughly $2.30 per test.
A blood glucose curve (BGC) tracks how your dog’s blood sugar responds to insulin over the course of a dosing interval. It usually begins with the morning meal and insulin dose, followed by regular blood glucose measurements over 8–12 hours. The results show how far insulin lowers glucose (the nadir) and how long its effect lasts (the duration of action). This information helps your vet understand why diabetes may be poorly controlled and guides safe adjustments to the insulin dose or timing.
A blood glucose curve can be done using a handheld glucometer or a continuous glucose monitor (CGM). A glucometer involves taking small blood samples every 1–2 hours, while a CGM (such as the FreeStyle Libre) uses a small sensor applied to the skin that continuously records glucose levels in the tissue fluid for up to 14 days.
The main advantage of a glucometer is that it provides accurate, real-time blood glucose readings, but it does require repeated pricks, which can be stressful and time-consuming. A CGM avoids repeated sampling and gives a much more complete picture of trends across the day, but the sensors can sometimes fall off early, they are not specifically calibrated for dogs so occasional readings may be off, and because they measure tissue glucose rather than blood glucose, they lag behind sudden changes and are less reliable for instant checks.
BGCs are far from perfect, though. Glucose levels naturally vary from day to day, even when nothing in the routine changes. A curve done on Monday may look very different from one on Tuesday, which is why interpreting results alongside clinical signs is essential. Stress can also cause artificially high readings in the clinic, so curves performed at home often give a truer picture of how your dog is responding.
Because blood glucose curves are labour-intensive, they are usually only performed when there is a clear reason to do so. A hospital-based BGC may be recommended on the first day insulin is started, mainly to ensure blood sugar does not fall too low. Curves are then typically repeated
A BGC can be performed either in the clinic or at home. In both cases, your dog should be fed and given insulin at the usual times so the results reflect their normal routine. Blood glucose is then measured every 2 hours for one dosing interval (usually 10–12 hours if insulin is given twice daily). If blood glucose falls below 8.3 mmol/L (150 mg/dL), samples may need to be taken hourly until levels rise again.
At the clinic, staff will collect the samples throughout the day. At home, you can use a handheld glucometer such as the AlphaTrak 3. A small drop of blood is collected from the ear, lip, or paw pad at each time point and applied to a test strip. Recording the results along with times of meals, insulin, and any unusual behaviour helps your vet interpret the curve.
Step-by-step:
Placement – Your vet will clip and clean a patch of skin (commonly on the side of the chest, shoulder, or hip) and apply the sensor with a spring-loaded applicator. This is quick and usually well tolerated. The sensor is then secured with medical adhesive, and sometimes covered with a protective patch or light bandage.
Activation – The sensor is “started” using a handheld reader or smartphone app. After a short warm-up period (about 1 hour), it begins recording glucose levels automatically.
Scanning – You can check readings at any time by holding the reader or phone close to the sensor. Each scan downloads the stored data, and the device also saves long-term trends.
Daily use – Continue your dog’s normal feeding and insulin routine. Try to scan several times a day (e.g. morning, afternoon, evening, before bed) to make sure the data is complete.
Care of the sensor – Avoid scratching or rubbing the sensor, and protect it with clothing, a vest, or over-tape if your dog is active. Some dogs may try to chew or scratch it at first. Ask your vet about bathing or swimming while the sensor is in place.
When to double-check – Occasionally, the Libre may underestimate very low readings (below 4.2 mmol/L / 75 mg/dL) or lag behind rapid changes. If the number doesn’t match how your dog looks, or if the sensor shows a very low value but your dog seems normal, confirm with a finger-prick test on a glucometer.
Removal and replacement – After 14 days (or sooner if it comes off), gently peel the sensor away. Your vet may apply the next one if continued monitoring is needed.
In general, insulin doses are adjusted to keep the nadir between 4.4–8.3 mmol/L (80–150 mg/dL) and to keep blood glucose under about 13.9 mmol/L (250 mg/dL) for most of the day. If the nadir falls below 4.4 mmol/L (80 mg/dL), a reduction in insulin is usually needed to avoid hypoglycaemia.
BGCs are also important for recognising the Somogyi effect, where an episode of low blood sugar triggers the body to rebound with very high levels (sometimes >22 mmol/L / 400 mg/dL). Mistaking this rebound for poor control can lead to dangerously increasing the insulin dose instead of reducing it.
The cost of monitoring your dog’s blood glucose curves depends on the method used.
Clinic-based glucose curve – Your dog stays at the clinic for the day while staff collect 5–6 blood samples. The total cost is usually NZD $150–$300, which includes the day stay, blood sampling, and veterinary interpretation.
At-home with a glucometer – Many owners monitor at home with a handheld device such as the AlphaTrak 3. The starter kit costs about $210, and ongoing supplies add up to around $2.30 per test (about $25 for 50 lancets and $90 for 50 strips).
At-home with a continuous glucose monitor (CGM) – The FreeStyle Libre 2 Plus sensor costs about $95 each and lasts up to 14 days. Your vet may charge an additional $70–$100 for placing the sensor and interpreting the results.
Fructosamine is a blood test your vet may recommend every few months (usually around every 3 to 6 months) to check how well your dog’s diabetes is being managed. Unlike a single blood glucose reading, which only shows what’s happening at that moment, fructosamine reflects your dog’s average blood sugar control over the past 2–3 weeks.
The test is done by taking a small blood sample, usually during a routine vet visit. It’s especially useful for spotting longer-term trends and making sure the overall treatment plan is working, even if day-to-day glucose levels vary.
In New Zealand, the average cost of checking fructosamine levels is usually made up of two parts: the office visit and blood draw, which typically runs from about $80–$120, and the fructosamine test itself, which usually costs $70–$90. Altogether, most owners can expect to pay around $150–$200 each time this test is performed.
Your vet will usually recommend a full physical exam every 3–4 months to make sure your dog is staying healthy and to catch any early changes. In addition to fructosamine, more detailed lab work such as a complete blood count, biochemistry panel, urinalysis, and sometimes a urine culture is advised at least every 6 months. These tests check organ function and screen for hidden problems like infections, which can interfere with good diabetes control.
Running a full set of blood and urine tests typically costs between NZD $250 and $450, depending on the clinic and which specific tests are performed.
You’ve now seen the different ways diabetes can be monitored, from simple home checks to more advanced veterinary tests. At the bare minimum, monitoring your dog’s clinical signs is essential. Beyond that, you and your vet can decide which additional tests are appropriate based on your dog’s needs, your comfort level, and your budget. The following table provides a summary of the main options. In most cases, it’s useful to have a glucometer and know how to use it — this can save money in the long term and give more accurate results at home.
Remember that your monitoring plan doesn’t need to be fixed; you can adjust it over time as your dog’s needs and your own situation change.
| Monitoring Tool | How Often | What It Involves | Typical Cost (NZD, per test) |
|---|---|---|---|
| Food Intake | Daily | Record % of meal eaten (0–100%) and time to finish ( minutes). | Free |
| Water Intake | Daily | Measure 24-hour bowl use or refills; note increases from usual pattern. | Free (one-off $5–$10 for measuring jug, optional) |
| Body Weight | Weekly to Monthly | Same scale, same time of day; watch trend (e.g., >2% change per week). | Free (one-off $25–$50 for pet/baby scale, if needed) |
| Urine Glucose & Ketones | Daily to Weekly | Dipstick test on fresh urine; look for patterns rather than single results. | $0.20–$0.30 per test |
| Blood Glucose Spot Test | As Needed | One-time check to rule out hypoglycaemia (home or clinic). | $2.30 per test at home (one-off purchase of glucometer $210) | $30–$50 per test in clinic |
| Blood Glucose Curve (BGC) | As Needed | Serial readings every 2 h over 8–12 h to assess nadir & duration. Can be performed at the veterinary clinic, at home with a glucometer, or at home with a continuous glucose monitor (CGM) | $150–$300 in clinic | ~$20–$25 at home with glucometer | $165 -$195 at home with CGM |
| Fructosamine | Every 3–6 mo | Blood test reflecting average glucose control over the past 2–3 weeks. | $150–$200 per test (incl. visit/blood draw) |
| Full Vet Check | Every 3–6 mo | Exam + CBC/biochemistry/urinalysis (± urine culture) to screen for health issues. | $250–$450 per visit |
Helping people understand animals and each other