What is the difference between hypoglycaemia and hyperglycaemia?

Both low blood sugar (hypoglycaemia) and high blood sugar (hyperglycaemia) can occur in diabetic dogs. They can both have serious consequences for your dog’s health and understanding the difference and the signs associated with each is crucial.  

What are the signs and symptoms of hypoglycaemia in dogs?

Hypoglycaemia – LOW blood sugar – is almost always associated with a relative overdose of insulin. Typically, either an accidentally high dose has been given or, more commonly, the correct dose has been given but the patient hasn’t eaten or has been sick. Hypoglycaemia is an serious emergency and if you suspect your dog is suffering then you should give treatment at home without delay. 

Signs of hypoglycaemia:  

  • Hunger, including stealing food/raiding bins. 
  • Weakness 
  • Trembling 
  • Disorientation 
  • Confusion
  • Hunger 
  • Drooling 
  • Collapse 
  • Seizures 
  • Coma 

What should I do if my dog shows signs of hypoglycaemia?

The normal blood sugar level in dogs is around 7 mmol/L but in the diabetic patient, we tend to keep it closer to 10 mmol/L.  

Anything lower than 5 mmol/L in a diabetic would be considered low, and anything lower than 3 mmol/L needs urgent treatment. 

If you can test your dog’s glucose, you should do so whenever you are concerned their glucose might be low. 

If you are concerned that your dog is showing signs of low blood glucose (hypoglycaemia), even if you can’t test it, then you should give treatment straight away: 

  • If your dog will eat, give them a bowl of their normal food. 
  • If your dog won’t eat, or is unable to eat, then give them some honey, golden syrup, maple syrup, glucose syrup or other high-sugar liquid (e.g., jam) 
  • If they are unable to swallow, or are unresponsive, then massage the sugary liquid into their gums. 
  • Contact your veterinary surgeon straight away for further advice and be prepared to attend the clinic immediately. 

What are the signs and symptoms of hyperglycaemia in dogs?

Hyperglycaemia – HIGH blood sugar – is almost always associated with a relative underdose of insulin. Most commonly this is due to either a dosing error, out-of-date or poorly stored insulin, or another health problem (especially an infection) that is stopping the insulin from working. Hyperglycaemia needs attention but is not typically an emergency. 

Signs of hyperglycaemia: 

  • Increased thirst 
  • Frequent urination 
  • Weight loss 
  • Lethargy 
  • Increased appetite 
  • Vomiting 
  • Difficulty breathing

Does my dog need to go to the vet for hypoglycaemia?

If your dog is having a hypoglycaemic episode, it can be an emergency. Contact your daytime practice if it is open and if not find your nearest Vets Now clinic.  If you’re not sure, you can call our Video Vets Now telehealth service for a consultation and advice.