Hyperglycaemic, hyperosmolar, non-ketotic (HHNK) syndrome

Hyperglycaemic, hyperosmolar non-ketotic (HHNK) syndrome is an uncommon complication of untreated canine diabetes. It is an emergency and the prognosis for recovery is poor.

HHNK syndrome is characterized by extremely high blood glucose levels. The brain may be affected resulting in the diabetic dog lapsing into a coma.


Before HHNK syndrome develops, typical clinical signs of diabetes mellitus are seen. The diabetic dog then becomes progressively weaker, stops eating, and lethargic and drinks less. The dog becomes severely dehydrated, depressed and eventually lapses into a coma.


Your veterinary surgeon will administer intravenous fluids and attempt to lower the blood glucose levels.


The prognosis for full recovery is extremely poor.