Have you ever been presented with a cat you are certain has hyperthyroidism, but you can’t prove it?
It is losing weight, but is eating ravenously, has a rapid pulse and, on occasions, has a palpable goitre – but can you detect an elevated total T4? No way!
Despite sometimes testing two or three times, its total T4 sits firmly within normal range.
The answer to this is to get a free T4 done – and lo-and-behold, this often confirms hyperthyroidism.