Low Blood Sugar in Cats

The body needs glucose to maintain its energy levels, which are necessary for the body’s organs, cells and various symptoms to carry out their daily functions. If a cat’s blood sugar levels drop, most cells can absorb fatty acids from the reserve located in the liver. However, the brain is a unique organ that cannot take glucose from anywhere else in the body, other than what is carried in by the blood. Therefore, when blood sugar levels drop, the brain quickly loses vital fuel and can no longer function at full capacity, resulting in weakness, sleepiness, disorientation as well as coma. Low blood sugar in cats is a life-threatening condition, especially to juvenile kittens, so immediate professional care by a licensed veterinarian is vital. 

Low blood sugar in cats is a symptom of an underlying disease that is causing the feline’s blood sugar levels to drop dangerously low levels. Low blood sugar, also known as hypoglycemia, can be the result of health conditions affecting the body’s blood glucose (blood sugar) regulators.

The symptoms of low blood sugar in cats, even in the warning stage, are easy to detect and often unsettling to cat owners. A cat with hypoglycemia is quickly losing brain power, resulting in neurologic disorders and an increased appetite as the body relies on food consumption for an energy supply. Depending on how low the feline’s blood sugar levels have dropped, symptoms could be mild to severe. 

Mild Low Blood Sugar

• Lethargy
• Drowsiness
• Pupil dilation 
• Tachypnea (breathing rapidly) 
• Palpitations of the heart
• Nervousness
• Nausea
• Appetite increase 

Moderate Low Blood Sugar

• Poor coordination 
• Tremors
• Shaking 
• Tilting of the head
• Weakness
• Disorientation 

Severe Low Blood Sugar

• Coma 
• Seizures
• Death

Low blood sugar in cats is caused by an underlying condition affecting the body’s ability to produce, release, or store insulin. The hormone, insulin, is a chemical messenger that is responsible for regulating the body’s blood glucose levels. The pancreas manufactures these metabolizing hormones and releases them when a cat eats a meal. As the meal is digested, the food glucose is absorbed by the blood. The rise in plasma glucose triggers the beta cells in the pancreas and insulin is secreted to keep a balanced blood sugar level. An interference of the production, balance, or distribution of this process can result in hypoglycemia including: 

• Diabetes: Diabetic cats can develop hypoglycemia upon overdose of insulin injection or if two doses overlap one another. 
• Blood Infections
• Pancreatic tumors
• Anorexia 
• Copious vomiting 
• Excessive exercise
• Addison’s Disease: A condition of the adrenal glands. The adrenal glands produce the cortisol hormone that balances the effects of insulin. 
• Glycogen storage disease: A condition that prevents the muscles and liver from properly synthesizing stored glycogen. A rare disease seen primarily in Norwegian Forest Cats. 

The following can cause blood sugar levels to drop due to a dysfunctional storage of glycogen: 

• Hepatic lipidosis
• Hepatic neoplasia 
• Portosystemic shunt                       
• Hepatic disease 
• Toxicity 

Your veterinarian will begin the diagnosis of low blood sugar in your cat by obtaining a full medical history. You will be asked to relay your cat’s current symptoms, diet, medications and past illnesses. The veterinarian will then continue with the following diagnostic tests: 

Physical Examination 

Jaundice or yellowing of the eyes can be an indication of liver failure that can lead to hypoglycemia. 

Urinalysis 

The current status of the cat’s kidney and liver function will be presented in the findings of a urine examination. 

Biochemical Profile

A test to evaluate the level of organ secretions and hypothesize their function status. 

Complete Blood Count

The number of white and red blood cells will help the vet determine if the presence of a possible blood infection. 

ACTH Stimulation Test

Cortisol hormone, produced by the adrenal glands, is measured to determine the level of gland function. 

Radiograph or Ultrasound

Imaging may be used to detect tumors.

Treatment of low blood sugar in cats ultimately begins with identifying the underlying cause, as hypoglycemia is a symptom and not a disease. Low blood sugar can be the result of a pancreatic tumor, a disease of the adrenal gland, a blood infection, or a result of toxicity. Talk to your veterinarian about the appropriate treatment plan for your cat and his/her low blood sugar.

Low blood sugar is a life-threatening condition, but if treatment is sought out immediately, your cat has a good chance of survival. There are a wide variety of treatment options for cats with hypoglycemia that should be discussed with a licensed veterinary professional.  Ask your veterinarian about treatment and an appropriate diet for cats prone to hypoglycemia and preventative care for the future.