Your diabetic dog and surgery

‍Why regulating your dog's diabetes matters before surgery

Based on our experience with Parker, our diabetic border terrier who has had several instances of going under for surgery or tests, your veterinarian will very likely want your dog’s diabetes to be well-regulated before surgery. 

This means their blood glucose levels are within a stable, healthy range — ideally without major highs or lows. Regulation helps your dog’s body handle the stress of anesthesia and reduces the risk of complications during and after surgery.

If your dog’s blood sugar is unstable, your vet may recommend postponing surgery until things are under better control. This is not to delay care unnecessarily, but to keep your pet as safe as possible.

We had a lot of challenges regulating Parker in the early days of his diabetes, so this information added to our anxiety. Could we get him regulated in time?

If that wasn’t enough, we learned that diabetic dogs can have greater risks than non-diabetics. 

Some risks to watch for with anesthesia

Here are a few anesthesia-related risks specific to diabetic dogs that his doctors have told us about:

• Blood sugar fluctuations – Stress, fasting before surgery, and anesthesia can all cause blood sugar to swing up or down unexpectedly.
  
• Delayed healing – Diabetes can slow wound healing, making infection prevention even more important.
  
• Increased infection risk – High blood sugar can weaken the immune system, making post-surgical infections more likely.
  
• Hypoglycemia (low blood sugar) – If insulin is given too close to surgery without food, blood sugar may drop dangerously low.
  

How vets prepare diabetic dogs for surgery

A good surgical team will take steps such as:

• Asking you to bring your dog in early in the morning so they can monitor blood sugar before anesthesia.
  
• Adjusting the insulin dose on the day of surgery — sometimes giving a reduced amount or delaying it until after the procedure. We were always told to bring his insulin on the day of surgery, so we used a silicon protective sleeve and chilly container.
  
• Placing your dog on IV fluids with added glucose if needed to keep levels steady during the operation.
  
• Monitoring blood sugar before, during, and after surgery.
  

What we learned to do as a pet parent

Work on regulation early – Don’t wait until surgery is scheduled to get your dog’s blood sugar under control.

Follow fasting instructions carefully – Usually no food after midnight, but always confirm with your vet.

Ask about monitoring – Make sure the clinic will track your dog’s glucose throughout the process.

Have a post-surgery plan – Your vet will guide you on when to restart your dog’s usual feeding and insulin schedule.

Monitor behaviour and blood glucose levels when you bring them home

We experienced Parker's first moment of very low blood glucose levels hours after he had surgery and had to apply honey on his gums to bring him into a safer zone.

We suspect that the clinic kept his levels in the 'butter zone' and, because he didn't have dinner post surgery and was anxious about the experience, his blood glucose dropped to 5.2 mmol/L around midnight.

It only happened that one time after surgery and we don't know if others would have the same experience, but we thought it important to share. With a diabetic dog it's always better to test their levels when you're unsure or something seems 'off' in terms of their behaviour or movements.

What we learned

Anesthesia for a diabetic dog does come with some extra considerations, but with preparation, a knowledgeable veterinary team, and careful monitoring, your dog can come through surgery just fine. The key is good communication with your vet and making sure your dog’s diabetes is well-managed before and after the big day.