More on hyperthyroidism in cats
The diagnosis of hyperthyroidism continues to be a problem in some cases. In the last year, I have handled two cats that had a spurious diagnosis of hyperthyroidism based solely on an elevated T4 from an in-house laboratory. I believe that there are three pieces to the hyperthyroidism puzzle and if you have all three, the puzzle is solved. If you have two of the three pieces, you are probably correct and should work diligently to find the third piece. The first piece is symptomatology. This can be very difficult because there are lots of manifestations of the disease. Also, due to routine screening by many practitioners, some are detected before they have symptoms. Not all cases have classic signs of weight loss and polyphagia so be suspicious with any older cat. The second piece of the puzzle is the thyroid nodule. These are not always easy to feel but their presence makes the diagnosis much more likely. The third piece of the puzzle is thyroid testing. As I have said before, if you are doing a routine screen, the samples should be sent to a reference laboratory. Thyroid testing is never an emergency! An elevated T4 and/or elevated free T4 is almost always conclusive as long as the other pieces of the puzzle fit. Normal T4 values with positive signs and a palpable nodule should be followed up with a T3 suppression test or at least a repeat T4 in a month or so. As always, feel free to contact me regarding these cases. Dr. Hause, Dr. Cocayne, Dr. Loyd and Dr. Brummitt have been treating your patients with hyperthyroidism for over twentyyears now. We have treated over 1000 cats! These cats have had the highest quality care with minimal complications since inception of our program. Call Dr. Wayne Hause with any questions.