Canine Diabetes Wiki
Dm 007b

Polyuria: Glucose cannot leave the body by itself--it must take water with it. Losing too much water means the body tries replacing it and this causes thirst, or polydipsia. When too much water is lost through excess urination and the excess drinking cannot make up for it, dehydration can occur.

Fluid loss routes

Fluid is lost from the body by breathing/panting (insensible), normal urination or polyuria,(urinary), and normal bowel movements or diarrhea (fecal). They're called sensible losses because they can be easily detected and measured. Vomiting fits into the sensible category and when it's severe, dehydration can take place, as well as with diarrhea and polyuria.

Dehydration is a generally dangerous condition for any animal, in which the tissues are low on water. It is particularly likely in poorly-regulated or hyperglycemic diabetics, and also particularly dangerous for them, because it can quickly trigger diabetic ketoacidosis.

The loss of fluids from the body is divided into two major categories--sensible and insensible. Sensible means able to be measured in some way; urination, defecation and vomiting are all in the sensible category because of their ability to be measured. Breathing is classed as insensible because while there is some fluid loss to the system from it, it's not possible to measure accurately. [1] In the case of fever, however, it's possible to say that there are insensible fluid losses that increase by 7% for each degree of higher than normal temperature. [2]

Those with diabetes are at risk for dehydration as it is triggered by hyperglycemia. [3]

Dehydration can change the way subcutaneous insulin is absorbed.  [4], causing either hyperglycemia or hypoglycemia [5] It can also create false positive or false negative urine ketone test results. [6]

Excessive thirst (medical term polydipsia [pah-lee-DIP-see-uh]; abreviated as PD) is a symptom of diabetes. Diabetic animals often drink incessantly because they are dehydrated from the cell-dehydrating effects of hyperglycemia, plus the effects of their bodies casting off the excess glucose through urination, taking hydration with it. The process also removes electrolytes [7] the body needs to function properly such as potassium, [8] sodium and chloride [9] also.[10]

To check if your pet is dehydrated, look at their gums and their skin. Skin will not snap back quickly when pinched, gums will be tacky or dry; more signs can be found at the links below. [1][11][12]

When the skin at the back is lifted, a dehydrated animal's doesn't fall back into place quickly. Serious dehydration (loss of 10-12% of body fluids) means the pulled up skin just stays there and doesn't go back into place. At this point, the animal may go into shock; dehydration of 12% or more is an immediate medical emergency. [2]

In any case of dehydration, check frequently for ketones. Mild dehydration may be possible to remedy with lots of water; if this isn't working, the next step is subcutaneous fluid injections, usually performed by your vet.

Untreated dehydration can cause the blood to be more hypertonic, which in turn can suck water from the cells causing more dehydration. Hypovolemic shock is a life-threatening medical condition in which the heart is unable to pump sufficient blood to the body, due to loss of fluids through either dehydration or bleeding. [14] I16


  1. 1.0 1.1 Assessing Dehydration Status. Washington State University.
  2. 2.0 2.1 Fluid Facts. Washington State University College of Veterinary Medicine. Cite error: Invalid <ref> tag; name "Fluid" defined multiple times with different content
  3. Hyperglycemia.
  4. Pediatric Endocrine Emergency Answer Sheet. American College of Emergency Physicians.
  5. Diabetes and Travel-page 4. DiabetesNow-UK.
  6. Ketosis and Dehydration. North American Veterinary Conference (2003).
  7. Stoeppler, Melissa Conrad. What Are Electrolytes?. MedicineNet.
  8. Potassium Requirements & Deficiencies. Pet Education.
  9. Sodium & Chloride Requirements & Deficiencies. Pet Education.
  10. Wortinger, Ann (February 2001). Electrolytes, Fluids and the Acid-Base Balance. Veterinary Technician.
  11. Water: A Nutritional Requirement. Pet Education.
  12. Assessing Dehydration Through Skin Elasticity in Dogs and Cats. Pet Education.
  13. Dehydration. Washington State University School of Veterinary Medicine.
  14. 14.0 14.1 Hypovolemic shock. University of Maryland Medical Center.

More Information[]