Results of thyroidectomy in 101 cats with hyperthyroidism.
OBJECTIVE
To describe outcome after thyroidectomy in hyperthyroid cats, with emphasis on peri- and postsurgical complications and recurrence.


METHODS
Retrospective study.


METHODS
One hundred and one hyperthyroid cats.


METHODS
Diagnostic work-up included preoperative measurement of plasma calcium, sodium, potassium, urea, and creatinine concentrations, and thyroid scintigraphy. A modified intracapsular dissection technique was performed. Postoperatively, parathyroid gland function was evaluated by measuring plasma calcium concentration several times daily. Outcome was obtained by standard telephone questionnaire.


RESULTS
Thyroid scintigraphy revealed ectopic hyperplastic thyroid tissue (EHTT) in 9 cats. Preoperatively, 29 of 91 cats had hypokalemia. Two cats died within 3 days after surgery and 5 of 86 cats developed postoperative transient hypocalcemia. On histologic examination, thyroid carcinoma was identified in 3 of 88 cats. Hyperthyroidism recurred in 5 cats between 3 and 59 months; 4 of these cats had EHTT preoperatively. The difference in recurrence rate between hyperthyroid cats with and without EHTT was significant (P<.001).


CONCLUSIONS
Complications were uncommon after thyroidectomy performed by an experienced surgeon when combined with an anesthetic regimen associated with minimal adverse cardiovascular effects. Hyperthyroid cats with EHTT had a significantly higher chance of recurrence.


CONCLUSIONS
Thyroidectomy is associated with a low incidence of surgical complications and is an effective treatment for hyperthyroid cats when radioactive iodine therapy is not available. Preoperative thyroid scintigraphy is advised. Surgery is not recommended when EHTT is present, because of a higher chance of developing recurrent disease.
Naan
Elaine C
EC
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. E.C.Naan@vet.uu.nl
Kirpensteijn
Jolle
J
Kooistra
Hans S
HS
Peeters
Marijke E
ME
D000818:Animals; D002371:Cat Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D002415:Cats; D018572:Disease-Free Survival; D005260:Female; D006980:Hyperthyroidism / Q000601:surgery / Q000662:veterinary*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011183:Postoperative Complications / Q000662:veterinary; D011877:Radionuclide Imaging; D011996:Records / Q000662:veterinary; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013965:Thyroidectomy / Q000379:methods / Q000662:veterinary*