• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.394-397
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• 1999

Thyroid imaging was performed in 53 hyperthyroid cats with technetium-99m as pertechnetate($^{99m}TcO_{4}$). Increased radionuclide accumulation was found in all cats. Thirty-four cats had bilateral enlargements of the thyroid glands and 14 cats had unilateral enlargements. Five cats had multi-focal accumulation of $^{99m}TcO_{4}$ in the ventral neck or mediastinum. Conclusively, nuclear thyroid image is useful method in diagnosis of feline hyperthyroidism.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.723-725
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• 2010

A 14-year-old spayed, mixed breed, female cat was admitted for evaluation of a polyphagia, hyperactivity and chronic weight loss. Physical examination revealed a tachycardia and mild elevated systemic blood pressure. This cat had azotemia and mild increased total thyroxin (TT4) and free thyroxin concentration. However triiodothyronine (T3) level was normal, the T3 suppression test for definite diagnosis were made. No changes of TT4 serum concentration before and after the exogenous T3 administration in this cat showed hyperthyroidism. This cat was diagnosed as mild hyperthyroidism concurrent with chronic kidney disease (CKD) and antithyroid drug, methimazole, was used for medical management. This is first case report describing clinical and laboratory characteristic features of feline hyperthyroidism complicated with CKD and its clinical outcome using medical management in our country.

• Korean Journal of Veterinary Research
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• v.64 no.2
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• pp.10.1-10.9
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• 2024

Hyperthyroidism, characterized by elevated thyroid hormone levels and thyroid gland hyperplasia or adenoma, is a prevalent endocrinopathy in older cats. Treatment options include antithyroid drugs, surgical thyroidectomy, and radioiodine therapy (RAIT), which is non-invasive treatment option that can achieve complete remission. However, efficacy and safety of RAIT in hyperthyroid cats have not been investigated in South Korea. This study includes 10 hyperthyroid cats with RAIT. Initial assessments comprised history, physical examination, blood analysis, and serum total T4 (tT4) concentration. Thyroid scintigraphy revealed hyperactivity and enlargement of thyroid gland at 24 hours before the RAIT. Radioiodine (RAI) was injected subcutaneously with 2 to 6 mCi, determined by the fixed dose or the scoring system based on severity of clinical signs, tT4 concentration, and thyroid size individually. After RAIT, the concentration of serum tT4 and liver enzymes were significantly decreased at discharge. However, no significant differences were noted in blood urea nitrogen, creatinine, symmetric dimethylarginine, hematocrits, and white blood cell counts pre- and post-treatment. Although 4 cats received RAI twice, clinical signs disappeared and tT4 levels decreased following the RAIT. All 10 cats achieved complete remission after 6 months without critical adverse effect. The safety and the effectiveness of RAIT was confirmed based on protocols reported other countries. Therefore, RAIT could be considered the treatment option and prevent adverse effects from medication or surgery. This preliminary study presents the first evaluation of RAIT for hyperthyroid cats using locally produced RAI in South Korea and provide valuable insight for clinicians and further studies.