Monday, December 27, 2010

What is Diabetes Insipidus?

Despite its name, diabetes insipidus is not related to the more commonly known diabetes mellitus, and it does not involve insulin or sugar metabolism.  The name comes from Greek, where it is roughly translated to mean the “excessive discharge of bland urine.”  This is in contrast to diabetes mellitus, which can be translates as the “excessive discharge of sweet urine.”

Diabetes insipidus is caused by problems with antidiuretic hormone (ADH or vasopressin), a pituitary gland hormone responsible for maintaining the correct level of fluid in the body. Either the pituitary gland does not secrete enough of this hormone (called central diabetes insipidus), or the kidneys do not respond normally to the hormone (called nephrogenic diabetes insipidus).

Affected dogs urinate in large volumes and drink equally large amounts of water. The urine is very dilute even if the animal is deprived of water (normally, urine becomes more concentrated when an animal is dehydrated.).

Increased urination may be controlled using desmopressin acetate, a drug that acts in a way similar to antidiuretic hormone. Water should not be restricted. Treatment is usually life-long.


Anonymous said...

Dr. Peterson,
I had a cat with partial diabetes insipidus, which I know is very rare in cats. We lost him recently to cancer (carcinomatosis in his abdomen). Now my other cat is starting to urinate larger volumes. She has always had a USG around 1050 and now it's at 1038. She has no evidence of kidney disease or diabetes mellitus on her most recent bloodwork or urinalyses, and is 8.5 year old. She is not genetically related to my cat who had DI (adopted in a totally different state from a different rescue). I am extremely concerned that there's something in our house that are cats are/were being exposed to, and that we are also being exposed to... What are the known risk factors for DI? Can it be caused by toxoplasmosis? Isn't DI so rare that having two unrelated cats get it in the same household a sentinel event? They even ate different foods- so that can't be it either. I am sooo worried I am ready to sell the house and move. Please let me know what you think.

Dr. Mark E. Peterson said...

It is not possible to have DI with a USG of 1.038. So this cat definitely does NOT have DI.

Anonymous said...

Thanks for responding! Would DI not develop progressively? Like first the USG is 1038, then 1020, then lower and lower? My other cat was diagnosed with partial DI at a USG of 1013, using a desmopressin trial. I just don't want the same thing to happen all over again.

Dr. Mark E. Peterson said...

Sure, but we wouldn't see signs until the USG became much lower.