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Screening blood glucose concentrations in healthy senior cats

Reeve-Johnson MK, Rand JS, Vankan D, et al. Cutpoints for screening blood glucose concentrations in health senior cats. J Feline Med Surg. 2017 Dec;19(12):1181-1191.


Diabetes is a common endocrine disease in cats, occurring in 1 in 50 to 1 in 200 cats. Risk factors include age, male sex, obesity and breed (Burmese are overrepresented in Europe and Australasia and Russian Blue, Maine Coon and Siamese in the United States).

While impaired fasting glucose is more often noted in humans, this condition is rarely diagnosed in cats. Mild increases in blood glucose are primarily attributed to stress hyperglycemia associated with a veterinary visit or with illness. It would be beneficial in cats as recognized with humans to be able to differentiate cats with transient hyperglycemia due to stress or eating, from cats with persistent mild increases in glucose (what is termed prediabetic status in people) so that appropriate therapy can be instituted before progression to clinical diabetes.

This study had 4 aims:

  1. To establish the reference interval for a screening blood glucose test in client-owned cats aged 8 years and older, measured on entry to the client from a pad or paw sample using a glucose meter calibrated for cat blood (screening blood glucose).
  2. To apply this in a population of obese cats.
  3. To determine whether selected variables account for variability in screening blood glucose (breed, body weight, body condition score, behavior score, fasting blood glucose, recent carbohydrate intake).
  4. To determine whether blood glucose is affected by changes in screening blood glucose methodology that could be expected in veterinary practice, such as using a jugular sample or external laboratory.

The study included 120 clinically health client-owned cats that were 8 years of age or older of varying breeds and body condition scores. The authors found that the reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Other factors such as breed, body weight, BCS, behavior score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 hr before sampling explained only a small proportion of the variability in screening blood glucose.

The authors concluded that-

  • A screening blood glucose be included in the health examination of all senior cats.
  • Cats with risk factors for diabetes and abnormal results should be retested to confirm they are persistent.
  • For those cats with persistently increased fasting glucose (impaired fasting glucose) or impaired glucose tolerance should have management strategies started to reduce the risk of future diabetes (particularly in cats with reversible risk factors such as obesity and corticosteroid administration).
  • When stress hyperglycemia is suspected, having blood glucose measured at home.

Additional specific recommendations are:

  • Cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later.
  • Cats with initial screening blood glucose > 189 mg/dl (10.5 mmol/l) or a second screening blood glucose > 116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalization. (VT)

See also:

Gottlieb S, Rand JS, Marshall R, Morton J. Glycemic status and predictors of relapse for diabetic cats in remission. J Vet Intern Med. 2015 Jan; 29(1): 184-192.