Research Communications of the 24th ECVIM-CA Congress

The author has received funding from BBSRC, Petplan Charitable Trust, and CRUK), but none of thesegrants were for this study. For each cat aged 10 years or older, irrespective of their suspected thyroid status, presented to eight veterinary practices in Portugal, the veterinarian and the pet owner had to complete a questionnaire and the veterinarian had to take a venous blood sample (into a plain tube) from the cat, after obtaining signed owner consent. The veterinary questionnaire included history, attitude, activity, heart rate and thyroid palpation. Cats aged <10 years and those diagnosed previously with hyperthyroidism were excluded. Blood samples were centrifuged and the serum harvested and stored frozen until collection by the laboratory within 2 days of sampling. Total T4 was measured using a chemiluminescent method (Immulite 1000, Siemens). Cats were classified as hyperthyroid, equivocal or euthyroid based on a total T4 concentration of >51 nmol/L, 30-51 nmol/L or <30 nmol/L, respectively. Repeat measurement of total T4 after 4-6 weeks was recommended for all equivocal cases. The individual cat was the statistical unit. Descriptive statistics was used to summarise the data and associations between different clinical signs analysed using Chi-square, Fisher's exact test or the Mann-Whitney U test. The level of significance was set at 0.05.