Reflections: then and now – diabetes

Let me tell you how the story starts. Not in a vet textbook. In a human ward. The year is 1922, Toronto General Hospital. Kids with type 1 diabetes were given a death sentence. Banting and Best purified insulin. But where did they get it? From dogs.

Dog pancreas gave human kids their first shot at life. But how did they know how much to give? How long would it last? What happened if they gave too much? Sound familiar?

Two decades ago, I diagnosed my first dog with diabetes. That was the easy bit. Then the real work started.

Glucose curve

I’d reach for the glucose curve. Admit for 24 hours. Blood every two hours. Adjust dose by 0.5 units. Admit again the following week. If that line wasn’t dipping, I assumed I’d missed something. Dogs spent a lot of time at the practice. I chased numbers.

Cats were tricky, too. Twice-daily injections, set meals and stress-hyperglycaemia that made the curve hard to read. If the owner couldn’t inject, options were limited. I remember trying a tablet once. Glipizide, maybe? That was 20 years and about 10,000 cases ago, and it didn’t work.

What changed?

Same disease, different focus – 20 years later. What changed? Honestly, in terms of canine treatment, very little. In terms of expectations, quite a lot.

I still curve dogs. But I start by asking different questions: what’s the weight doing? Is the dog bright? Drinking less? Gaining muscle? Playing ball again?

If yes, I worry less about that perfect dip. Real life happens, work shifts, long days. We do our best. Stable used to mean perfect glucose to me. Now, I’d call a dog managed if it has a good quality of life, no side effects, and symptoms are under control.

For cats, the flip is bigger. There are other options. Now, I ask: is this cat a Senvelgo candidate? If it’s a well cat, with no current or prior diabetic ketoacidosis, then the owner has a choice. The way it works is baffling. It blocks kidney glucose reabsorption, so existing beta cells function better.

“Working” used to mean a cat that tolerated injections. Now, it might mean a cat sleeping on the sofa after a medicated breakfast. Diet matters more in cats, but with picky eaters, any food is better than none.

Not all cats are candidates, so it’s back to insulin. But even then, a FreeStyle Libre sensor at home gives us trends for two weeks and not just one stressed curve at the practice.

Researching this reminded me: those kids in 1922 didn’t get “perfect glucose”. They got life. More time.

Banting and Best were not chasing numbers. Now, neither am I.

• This article appeared in Vet Times (1 September 2026), Volume 56, Issue 35, Page 10

Kirsty Marshall graduated from the University of Glasgow in 2005 and has worked in primary care and OOH since that time. Kirsty has also been a portfolio assessor for the University of Glasgow since 2018.