One of the “Big Three” diseases we see in middle-aged and older cats, hyperthyroidism frequently presents with an increase in energy levels that may mimic a “second kitten-hood”. Do not be fooled! The thyroid gland is responsible for regulating your cat’s metabolism. If it starts making too much hormone (hyperthyroidism), your cat’s metabolism goes into “overdrive”. He/she will no longer be able to eat enough to make up for all of the calories being burned. Internal organs are stressed and eventually will “burn-out” if untreated.

Clinical signs can include any of the following:

  • Increased energy levels
  • Changes in personality (hyper, irritable, etc)
  • Increased to ravenous appetite
  • Weight loss
  • Increased vocalization (often at night)
  • Occasional vomiting
  • Hard stools, sometimes with blood or mucous present
  • Increased water intake
  • Increased urination
  • Inappropriate urination or bowel movements
  • Facial twitching/seizures

This disease can be managed with daily medication (pill, flavoured liquid, transdermal gel) or in some cases with a new prescription diet specifically for these cats.  Radioactive iodide treatment is available and considered to be curative.


hyperthyroidism in cats