Dogs and cats use sugar (glucose) as their main source of energy in the body. The brain can only use glucose as its source of energy, whereas most other parts of the body can use alternate fuels under times of stress. Glucose levels are maintained within strict levels by the body through the use of hormones; including insulin and glucagons among others. When the blood sugar level falls below a certain level (usually 60 mg/dl) we call it hypoglycemia, and clinical symptoms develop which include:

  • Weakness
  • Lack of Coordination
  • Vomiting
  • Abnormal Vocalization
  • Stupor
  • Seizures

In order to understand hypoglycemia, it helps to have a basic understanding glucose metabolism in the body.

Sugar can be absorbed directly across mucous membranes anywhere in the gastrointestinal tract, or it can be manufactured in the liver. The three main food groups are proteins, fats and carbohydrates. Carbohydrates include simple and complex sugars. Simple sugars can be absorbed directly into the blood stream across a mucus membrane. Complex carbohydrates are broken down to simple sugars in the intestines and absorbed into the bloodstream. The absorbed glucose can enter cells that need it if insulin is present to promote the passage of glucose into the cell. In times of glucose excess, the liver will transform glucose into glycogen, which is a storage molecule. If there is a chronic excess of calories taken in, the sugar will be converted to fat for storage. Glycogen can be rapidly converted to glucose in times of need.

Proteins are broken down into amino acids, which are absorbed into the bloodstream and transported to the liver where they can be used to create new proteins or be broken down into glucose. Fats are broken down into fatty acids and cholesterol molecules and absorbed into the blood stream. They are transported to the liver where they can be used to build different body components, stored as fat molecules or broken down into an alternative fuel called ketone bodies.

How does hypoglycemia occur?

If there is a lack of food, the body will do all it can to maintain blood sugar levels including breaking down glycogen and proteins to form glucose. Unfortunately, small animals and particularly young puppies and kittens do not have a lot of sugar stored in the form of glycogen and so they are subject to becoming hypoglycemic very easily. Sometimes, animals may secrete too much insulin (or if they are diabetic and are being given insulin injections they may overdose) which will drive all the sugar out of the blood into the cells of the body, leading to hypoglycemia.

How does our veterinary clinic prevent hypoglycemia?

Hypoglycemia is simple to prevent by feeding small pets at the right frequency. Young puppies that are nursing should be fed every 2-3 hours until 2 weeks of age and then every 3 to 4 hours.

Week 1Week 2Week 3Week 4
Calories per ounce of body weight per day3.754.5 calories/oz5.0 calories/oz5.5 Calories/oz

In general, milk substitutes contain around 1 calorie per ml.

Example: You plan to feed a 5-ounce puppy less than 1 week of age 4 times daily. The puppy requires 3.75 calories/ounce body weight x 5-ounce pup = 18.75 calories needed for one day. You are feeding 4 times a day. Therefore, 18.75/4 = 4.68 calories given at each feeding. Your milk substitute contains 1 calorie/ml. Therefore, you should feed 4.68 ml (about 5 ml) each feeding.

Solid foods should be introduced at 3 weeks of age. Pan-feed a thin gruel made by blending good-quality puppy food with puppy’s milk formula. Gradually thicken the gruel until no milk substitute is used at about 6 weeks of age. At this time, the pups should be offered good-quality puppy food 3 times daily.

Many teacup and toy breeds remain at risk for hypoglycemia even after they are weaned onto solid food. These pets should be fed 4 times daily until they are 6 months of age, then 3 times daily until one year. After that twice daily feeding should allow them to maintain adequate glucose levels.

How do our veterinarians treat hypoglycemia?

Pets that are suffering from hypoglycemia need to get sugar into the blood stream as quickly as possible. Unfortunately, by the time they are significantly hypoglycemic, they may not be hungry or able to eat on their own. You should keep a bottle of Corn syrup (kayro) in your pantry to have on hand if your pet appears to be hypoglycemic. If you place some corn syrup in the mouth and rub it on the gums, it will be absorbed directly through the mucous membrane of the oral cavity and start to raise the blood sugar. You can also use honey, or a strong solution of sugar. Try to get a few teaspoons of corn syrup into your pet within a few minutes. As soon as they start to respond, feed them with milk replacer (if puppies) or canned food.

If your pet is seizuring due to the low blood sugar, try to get the sugar in the mouth without getting bitten. If seizures have occurred, bring your pet directly to the veterinarian.

With knowledge of the symptoms of hypoglycemia and an appropriate feeding plan, this problem is largely avoidable in most pets of Alta Loma, Rancho Cucamonga, Upland, Ontario, Claremont, Fontana and the Inland Empire.