Background: Many non-thyroidal factors affect thyroid function tests. Anesthesia and surgery have been documented to affect thyroid function tests in humans but have not been extensively studied in dogs. Hypothesis: Anesthesia alone and anesthesia combined with surgery will affect thyroid function tests in dogs. Animals: 15 euthyroid mongrel dogs. Methods: Dogs were assigned to one of three groups: control, general anesthesia, and general anesthesia plus abdominal exploratory surgery. Blood samples were collected from each dog immediately prior to pre-medication, 20 minutes after pre-medication, 55 minutes after anesthesia induction, once daily for an additional 6 days, and 14 days post-procedures. Sampling was performed at identical times in the control group. Thyroxine (T4), free T4 (fT4) by equilibrium dialysis, triiodothyronine (T3), reverse T3 (rT3) and thyroid-stimulating hormone (TSH) concentrations were measured in all samples. Results: Results of all thyroid function tests were not significantly different between control and anesthesia groups. Serum T3 for the surgery group decreased significantly from baseline compared to the control and anesthesia groups at multiple times. Serum T4 and rT3 for the surgery group increased significantly from baseline compared to the control and anesthesia groups at multiple times. Serum fT4 for the surgery group increased significantly from baseline compared to the control and anesthesia groups at 48 hours only. Conclusions and Clinical Importance: Surgery has a significant effect on thyroid function tests, while the anesthetic protocol used in this study does not. Because serum T4 and fT4 concentrations increased rather than decreased, evaluating these hormones following surgery is unlikely to lead to a misdiagnosis of hypothyroidism in euthyroid dogs. / Master of Science

No description available.

No description available.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23078号 / 医博第4705号 / 新制||医||1049(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 稲垣 暢也, 教授 万代 昌紀, 教授 小杉 眞司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM