A 10-year old male castrated cat that you have previously diagnosed with hyperthyroidism presents to you for acute onset of blindness. You perform an ophthalmic exam and note retinal hemorrhage. What diagnostic test should you perform first?
一只10岁的已绝育有甲亢病史的公猫由于突然失明前来就诊。你进行了眼科检查后发现了视网膜出血。你将首先做哪个诊断性试验？
A Coagulation times 凝血测试
B Blood pressure 血压
C Free T4 levels by equilibrium dialysis 层析法检测fT4
D Total T4 levels TT4
E Serum BUN and creatinine 血清尿素氮和肌酐