ORIGINAL_ARTICLE Hyperthyroidism in the domestic cat (felis catus): informed treatment choice based on survival analysis Hyperthyroidism is the most frequently diagnosed endocrine disorder in cats. Therapy may include pharmacological, surgical (thyroidectomy), radioactive (iodine), and dietary treatment. The choice of treatment is believed to be strongly influenced by the veterinarian’s experience, level of education, and knowledge of the current scientific literature. The history of survival rates can affect the decision for treatment by both the veterinarian and the owner. This study aimed to explore the longevity in cats diagnosed with hyperthyroidism and to identify significant variables which affect survival rates by using retrospective data from the practice. A multivariate Cox regression was applied with the following results: surgical thyroidectomy and methimazole medication produced similar longevity (median 23.5 months, P>0.05); Domestic Short Hair cats survived longer than pure breeds (median 27.2 vs 9.4 months, P < 0.05); as do cats without chronic renal disease (median 28.1 vs 6.2 months, P < 0.001); and those with low activities of alanine aminotransferase (median 27.1 vs 17.0 months, P < 0.01). Hyperthyroidism is comorbid with renal diseases, but no cumulative effect was found on survivability. There was no difference in survival rates between surgical and pharmaceutical treatment, therefore the discussion of treatment options with owners can focus on other factors (e.g., cost, owners’ compliance, cats’ tolerance to medication, presence of comorbidities). We propose that surgery may be the preferred treatment when the survival rates are expected to be higher than one year. This would avoid high costs and potential side effects of medication. https://macvetrev.mk/Files/Article/2022/10.2478/macvetrev-2022-0015/macvetrev-2022-0015.pdf 2022-03-15T09:00:00 71 78 10.2478/macvetrev-2022-0015 cats hyperthyroidism methimazole treatment survivability thyroidectomy Fernando Mata fernandomata@ipvc.pt false 1 Center for Research and Development in Agri-food Systems and Sustainability (CISAS), Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial Nun’Alvares 4900-347, Viana do Castelo, Portugal LEAD_AUTHOR Ravneet Bhuller false 2 National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, United Kingdom AUTHOR Broussard, J., Peterson, M., Fox, P. (1995). Changes in clinical and laboratory findings in cats with hyperthyroidism from 1983 to 1993. J Am Vet Med Assoc. 206(3): 302-305. 1 Peterson, M. (2020). 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