Hypoglycaemia in Dogs: Causes, Affected Breeds and Preventive Measures

A Chihuahua that was just darting across the flat – and suddenly lies motionless in its basket. A Yorkshire Terrier trembling all over its body and simply not responding, no matter how many times you call its name. Anyone with a small dog may know this moment of terror. Hypoglycaemia, i.e. low blood sugar, affects small breeds more often than many owners realise – and it usually comes without any warning.

Symptoms: How do I recognise hypoglycaemia in dogs?

The dog seems like a different creature. Just moments ago full of life, now drowsy, unsteady, somewhat absent-minded. Once blood sugar levels drop below 60 mg/dl, the brain starts to strike – and you can tell. The trembling usually begins in the hind legs and works its way forward. Some dogs become unusually clingy at such times, seeking physical contact and refusing to leave your side.

It becomes truly dangerous when the dog no longer responds to being spoken to or simply collapses. By then, blood sugar has already dropped below 40 mg/dl – this is an emergency, not a situation for waiting and seeing.

Why small dog breeds are particularly affected

A 2-kg Chihuahua burns significantly more energy proportionally than a 30-kg Labrador. The tiny body simply stores less glucose – there is simply less room for it in the liver and muscles. At the same time, metabolism runs at full throttle. Four hours without food? Reserves are gone.

In puppies under six months old, this is even more pronounced: Their brains need approximately twice as much glucose per kilogram of body weight as an adult dog’s brain. Add stress as an accelerant – an excited Toy Poodle at the vet can literally become hypoglycaemic within minutes.

Causes beyond an empty stomach

Too little food is the most obvious cause – but by no means the only one. Liver problems often play a role: The liver stores glucose and releases it when needed. If this mechanism does not work properly, blood sugar drops despite regular feeding. Older dogs with chronic liver diseases therefore often have recurring episodes of hypoglycaemia.

Even more insidious are insulinomas – tumours of the pancreas that secrete insulin uncontrollably. Blood sugar then drops even immediately after eating, which completely confuses many owners. Addison’s disease also belongs in this category: Due to hormone deficiency, blood sugar levels become unstable in a hardly predictable way.

Immediate measures for acute hypoglycaemia

Apply glucose syrup to the lips – and only to the lips, not into the throat. A pea-sized drop of Jubin from the pharmacy works well; in an emergency, a teaspoon of honey will do. The mucous membranes absorb the sugar within seconds. Important: Never pour anything into the mouth of an unconscious dog – risk of choking.

After two or three minutes, offer a small portion of food – meat or liver sausage are ideal. Carbohydrates alone are not enough; they cause blood sugar to crash back down quickly. For small dogs, a teaspoon is sufficient; for larger ones, a tablespoon.

Seizures, unconsciousness, or the symptoms simply do not improve after administering glucose? Then go to the vet immediately. Only an intravenous glucose infusion can truly stabilise circulation at that moment.

Prevention: How you can prevent further hypoglycaemic episodes

Three to four small meals a day are better than two large ones – for susceptible dogs, this is not just a recommendation, but actually a must. Puppies under four months need food every three hours, even at night. A small snack directly before sleeping helps stabilise blood sugar during the longest break.

High-quality protein keeps levels more even than cereals. Dry food with at least 25% protein and 15% fat works noticeably better for at-risk dogs than standard products.

And stress? Can be reduced more concretely than many think: No long car rides on an empty stomach, feed a little something quickly before vet visits, offer smaller portions more often in the heat.

Why does this happen despite regular feeding?

If the dog eats normally but still becomes hypoglycaemic repeatedly, there is almost always an underlying illness. Liver problems, Addison’s disease, an insulinoma – all of these require veterinary diagnosis and treatment. No feeding strategy in the world replaces therapy when an organ no longer functions properly.

Are large dog breeds also affected?

Yes, but significantly less often. Golden Retrievers or German Shepherds usually develop hypoglycaemia only with severe underlying conditions. Their larger glucose reserves simply buffer normal fluctuations better.

Can I treat hypoglycaemia with sugar from the kitchen?

Household sugar works in an emergency, but is not the first choice. Dextrose or glucose syrup enters the bloodstream significantly faster. Chocolate, however, is poisonous to dogs – it is out of the question, no matter how desperate the situation seems.

When do I need to go to the vet?

The cause should be investigated after every first episode of hypoglycaemia. Go to the practice immediately in case of unconsciousness or seizures – or if symptoms do not improve within ten minutes after administering glucose.