Pay attention to the scale you’re using to measure your dog’s blood glucose.

There are two Main Units: mg/dL vs. mmol/L

Blood glucose can be measured in:

• Milligrams per deciliter (mg/dL) — This is the most common unit in the United States and is also used in countries like Japan and South Korea.‍
• Millimoles per liter (mmol/L) — This is the standard in most other developed countries, including Canada, the UK, Australia, and much of Europe.

It’s a bit like measuring distance in miles vs. kilometres — the numbers look different, but they mean the same thing.

How to convert between units

If you’re trying to compare readings between the two systems:

• To convert mg/dL → mmol/L: divide by 18
• To convert mmol/L → mg/dL: multiply by 18

So, for example, a reading of 180 mg/dL in the U.S. would be 10 mmol/L in Canada.

Why this matters for dog owners

If you’re reading advice, charts, or glucose curves from another country, knowing the difference in measurement units will help you avoid misunderstandings — especially when deciding if your dog’s blood sugar is in a safe range.

When using a blood glucose monitor like AlphaTrak or PetTest, you want to make sure it’s set for your region.

One morning I noticed that Parker’s blood glucose reading was unusually high. I thought I had read 37.8 on the meter – we’re in Canada so that would be very high – but I didn’t have my glasses on and it was actually 378.

I assumed a decimal point where there wasn’t one. The meter had somehow reset to the US and was showing mg/dl and not mmol/L. So Parker was actually 21, which is a bit high but not unusual for him in the morning after a low activity day.

Quick tip

We’ve found it handy to jot down our dog’s readings in both units when sharing information with an international online community like Facebook or reddit groups.