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Last updated January 1, 2014

Hypoglycemia and Hyperglycemia in Reptiles

©2001 Melissa Kaplan


The plasma glucose concentration in reptiles varies by species, on a species-by-species level as well as normal seasonal fluctuations for some species. Glucose concentration will also be affected by conditions of captive care: environment, diet, nutritional status, and health status.

According to Campbell [1], blood glucose in reptiles ranges from 60-100 mg/dl. Diabetic test strips for humans can be used to determine whole blood glucose are useful for reptiles, requiring the use of a drop of whole blood. A pediatric diagnostic test for glucose in whole blood can be used; this provides results ranging from 10-800 mg/dl. The test strips are useful for small reptiles and when tracking abnormal glucose progression in reptiles.

Hypoglycemia (too little/low plasma glucose) can result from the following:


  • high protein diet (for the species)
  • malnutrition
  • starvation
  • malnutrition


  • endocrine system disorders
  • liver disorders
  • pancreatic disorders
  • systemic infection

Symptoms of hypoglycemia include:

  • dilated or nonresponsive pupils (in some species)
  • loss of righting reflex (when on back or side, the reptile cannot right itself)
  • tremors
  • torpor

Since these symptoms are common to other common disorders (metabolic bone disease, kidney failure, inclusion body disease, hypothermia, amoebiasis, hypothiamineosis, etc.), the presence of these symptoms should not be assumed to be due to hypoglycemia; instead, the reptile must be examined by a reptile veterinarian.


Persistent plasma blood levels in excess of 200 mg/dl is rare in reptiles, as is glucosuria (glucose excreted in urine/urates). Causes in reptiles are ill-defined. In humans, it can be due to pancreatic disorders, an autoimmune response to the pancreas, lack of any or sufficient insulin production, adequate but poorly utilized insulin, high sugar intake, or obesity. Since reptiles are rarely given refined sugars and most species ingest relatively little plant sugars, diabetes mellitus in reptiles may be related to an endocrine or pancreatic disorder.

In other animals, symptoms of hyperglycemia include:

  • increase water consumption
  • increased urination (urates)
  • increased food intake
  • weight loss

Since all of these signs are common in other disorders or stress, the reptile's environment (physical and social) needs to be thoroughly checked out and veterinary attention sought if the problem something that can be fixed by correcting an environmental problem. While increased fluids and food consumption is common seasonally in many species (associated with breeding season or preparatory to hibernation) one should get the reptile checked out if this behavior occurs outside of these seasonal fluctuations.

Note: blood glucose tests done within a relatively short time of food ingestion will show a higher glucose level than a test done when the gut is essentially empty. Since digestion rates in reptiles is dependent upon the species, activity level, environmental temperatures and thermoregulation, an initial test result of high glucose should be retested several times (as with a clinical test strip) to see if it is persistent.

1.    Campbell, TW. Clinical Pathology, in Reptile Medicine and Surgery, DR Mader, editor. 1996. WB Saunders.

More at PubMed, keywords: hypoglycemia OR hyperglycemia AND reptile

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