Ketones, Ketoacidosis, and Diabetic Cats: A Primer on Ketones

What are Ketones?
Ketones or ketone bodies (acetone, acetoacetic acid, and beta-hydroxybutyric acid) are waste products of fatty acid breakdown in the body. This is the result of burning fat, rather than glucose, to fuel the body.

The body tries to dispose of excess ketones as quickly as possible when they are present in the blood. The kidneys filter out ketones and excrete them into the urine.

Should you care about ketones?
YES! If they build up, they can lead to very serious energy problems in the body, resulting in diabetic ketoacidosis, a true medical emergency. If the condition is not reversed and other systemic stresses are present, ketones may continue to rise and a condition known as diabetic ketoacidosis (DKA) may occur. This condition can progress very quickly and cause severe illness. It is potentially fatal even when treated. Recognition of DKA and rapid treatment by your veterinarian can save your cat's life. Please note that even cats in normal numbers may develop ketones!

Signs of Diabetic Ketoacidosis (DKA)

• Drinking excessive amounts of water OR no water
• Excessive urination
• Diminished activity
• Not eating for over 12 hours
• Vomiting
• Lethargy and depression
• Weakness
• Breathing very fast
• Dehydration
• Ketone odor on breath (smells like nail-polish remover or fruit)

Causes of Diabetic Ketoacidosis (DKA)

• Insulin dependent diabetes mellitus
• Inadequate insulin dosing or production
• Infection
• Concurrent disease that stresses the animal
• Estrus
• Medication noncompliance
• Lethargy and depression
• Stress
• Surgery
• Idiopathic (unknown causes)

Risk Factors for DKA

• Any condition that causes an insulin deficiency
• History of corticosteroid or beta-blocker administration

Testing for Ketones

It is important to note that while ketones are more of a concern if the BG is high (which generally signals the cat is not getting enough insulin), it is possible for cats with a lower BG to have ketones and develop DKA. The premise behind this is the cat might be developing ketones, not eat, vomit, and the BG drops. Therefore, it is recommended to test for ketones even if the BG is lower, if the cat is not bright, alert, eating, and drinking normally.

Simple urine tests can detect ketones. This is done by collecting a urine sample and inserting a special dip stick into the urine. Some urine ketone strips detect only ketones while other types test for both glucose and ketone levels. Urine ketone strips will detect only some of the ketone bodies produced by the body, not all of them. Strip storage, handling, and testing procedures are similar to those used for glucose test strips. Strip test results are indicated by presence of color changes, indicating presence of ketones, either quantitatively (giving you a number for the ketone concentration) or by descriptive terms (for example, negative, trace, small, or large). False positives may occur if you are also using certain medications or vitamins, or if the strips have been handled or stored improperly. It is extremely important to follow the directions on use of the urine ketone test strips as the time to read the strip is generally within 15 seconds but may vary by brand.

An example of how a urine ketone test strip might look are shown below:



Trace ketones warrant close following and more attention to calories and liquids consumed, BG levels, and whether it appears any type of infection is evident. If a kitty has more than “trace” ketones, it’s important to take it to the vet immediately for further testing.

If you wish to test blood instead of urine for ketones, there are four meters that allow for home testing; most members use the Nova Max Plus Glucose and Ketone Testing Meter or the Abbott Precision Xtra Meter. The premise behind blood testing for ketones is the same as that for favoring glucose testing of blood over urine. Some of the meters also do glucose testing with meter-specific glucose test strips. Blood ketone strips can be obtained at American Diabetes Wholesale.

When do ketones show up on a blood ketone meter such as the Nova Max Plus or Precision Xtra Blood & Ketone meters?

Two of the latest scientific studies (linked below) concerning measurement of ketones when using a blood ketone meter provide an up-to-date interpretation that when a blood ketone concentration of 2.4 and 2.55 are obtained, DKA is more likely to be present.

Measurement of ketones - Weingart_J VET Diagn Invest-2012(1).pdf
Measuring ketones - JSAP_Zeugswetter - 2012.pdf

When to call the vet
In a diabetic, any urinary ketones above trace or trace urinary ketones plus some of the signs listed above, are cause to call a veterinarian immediately. If your vet doesn't offer after-hour emergency care, be sure to have the number and location of a 24 hour emergency veterinarian.

Diagnosis
Laboratory tests performed by your vet are necessary for diagnosis. Depending on how sick your cat is, the testing can be extensive (and expensive). Your veterinarian will determine what tests are necessary. At a minimum, testing is likely to include a number of blood tests and a urine test.

Treatment
If the cat is bright, alert, and well-hydrated, the cat will not require intensive care. Your cat will require insulin, food, constant access to water, and close monitoring for signs of illness such as vomiting, anorexia, and lethargy. If a cat is showing trace ketones but is still eating, drinking, and is bright and alert, it is possible to increase the % calories from carbs of food (even up to high carb) in order to increase the insulin dose. Although not as common, it is possible for cats with a lower BG to have ketones and develop DKA.

Treatment of cats who show signs illness require inpatient intensive care. The goal of treatment is to correct dehydration, electrolyte depletion, to reverse the high ketones in the blood and the metabolic acidosis that is present, and to increase the rate of glucose use by insulin-dependent tissues.

Veterinary care for DKA involves intravenous (IV) fluids, usually supplemented with potassium, monitoring by observation and urine and blood tests, and sometimes feeding by a tube. Treatment may involve a hospital stay of five days or more and often costs about US$2000. Without treatment, "sick" animals with DKA will die.

An additional resource from the Veterinary Information Network regarding the treatment of DKA can be found here.



Document originally published on www.felinediabetes.com; updated January 20, 2024 by Marje and Gracie.