Case summaryA 14-year-old Siamese neutered male cat was evaluated for anorexia and a left periorbital mass. Skull radiographic findings showed a well-defined lesion resembling new compact bone formation without destruction. A subtotal orbitectomy was indicated. The tumor was removed intact with a normal tissue margin of at least 1 cm. There were no postsurgical complications. Histopathologic examination revealed an osteoma. The cat returned to normal appetite and activity 15 days after surgery. Six months after surgery, there were no gross signs of recurrence.Relevance and novel informationPeriorbital tumors are infrequently diagnosed in companion animals and most are malignant. In this case, the diagnosis was orbital osteoma. The most commonly affected bone for osteoma in cats is the mandibular bone; few cases have been identified in orbital bones. Orbital surgery has the potential to be challenging owing to complex anatomy, difficult exposure and the tendency to bleed. Surgical complications are common. In this case, although the disease was advanced, subtotal orbitectomy was successfully performed.

ResumoO objetivo deste estudo é avaliar as concentrações de cálcio ionizado e paratormônio intacto (iPTH) após a tireoidectomia com implantação da paratireoide em gatos hipertireoideos. Gatos hipertireoideos podem apresentar hipocalcemia por apresentarem distúrbio na homeostase de cálcio. A tireoidectomia pode levar a hipocalcemia pós-operatória, sendo, portanto, fundamental a mensuração dos níveis de cálcio antes da cirurgia em pacientes hipertireoideos. Dezessete gatos com hipertireoidismo com lobos cervicais palpáveis foram examinados e avaliados laboratorialmente para a cirurgia. Tireoidectomia unilateral com implantação da glândula paratireoide foi realizada. Hemograma completo, ureia, creatinina, fosfatase alcalina, alanino aminotransferase, fósforo, potássio e tiroxina total foram realizados antes e sete dias após a cirurgia. Amostras de sangue para avaliar cálcio ionizado e paratormônio intacto foram coletadas antes e nos dias 1, 2, 7, 15 e 21 após a cirurgia. Os níveis séricos de cálcio diminuíram significativamente em 24 horas após a cirurgia. Hipocalcemia subclínica ocorreu em dois gatos. As concentrações de iPTH foram uniformemente baixas ao longo do estudo e não avaliaram a função da glândula paratireoide após a tireoidectomia nesses gatos. Não houve correlação entre os níveis de cálcio e de iPTH. Os resultados deste estudo sugerem que os níveis de iPTH não indicam função da glândula paratireoide e que os níveis de cálcio devem ser avaliados antes da tireoidectomia, mesmo nos casos de tireoidectomia unilateral.Palavras-chave: calcemia, gatos, hipertireoidismo, paratireoide. AbstractThe aim of this study was to measure ionized calcium and intact parathormone concentrations after unilateral thyroidectomy with parathyroid autotransplantation in hyperthyroid cats. Hiperthyroid cats may have calcium homeostasis disorder and have decreased calcium concentration. Calcium levels decrease after thyroidectomy and their levels must be measured before thyroidectomy. Seventeen hyperthyroid cats with palpable nodules were submitted to clinical and laboratorial examination and they were prepared to surgery. Unilateral thyroidectomy with parathyroid gland autotransplantation was performed. Concentrations of serum urea, creatinine, alkaline phosphatase, alanine aminotransferase, phosphorus, potassium, total thyroxine and hematologic profile were determined before and seven days after surgery. Blood samples for serum ionized calcium concentration were collected before and after surgery on days 1, 2, 7, 15, 21. Serum calcium concentration fell significantly in all cats within 24 hours after surgery. Hypocalcemia occurred in two cats without clinical signs. The iPTH concentration measurements for samples throughout the study were uniformly low, with no patterns or trends identified. There wasn't correlation between serum calcium levels and iPTH levels in any moment before and after surgery. iPTH couldn't indicate parathyroid gland function after thyroidectomy in cats. The results of this study suggest that calcium conc...