Percutaneous ethanol injection for treatment of unilateral hyperplastic thyroid nodules in cats

Abstract

Ultrasound-guided percutaneous ethanol injection (PEI) was evaluated in 4 cats as a treatment for a unilateral hyperplastic thyroid nodule. Cats were anesthetized with a short-acting agent, and a 27-gauge needle was directed into the thyroid nodule with guidance by ultrasound. A precalculated dose of 96% ethanol solution was injected, and diffusion of the fluid throughout the gland was readily apparent. Serum thyroxine (T4) and free T4 concentrations decreased to or below reference ranges in all cats within 48 hours, and remained so during the 12-month study period. All cats have been assessed as clinically normal and have had no clinical signs of hyperthyroidism since PEI. No severe adverse effects were observed. Results of follow-up pertechnetate scans were normal in 2 cats and abnormal in 2 cats. We concluded that PEI is likely a safe and efficacious treatment for hyperthyroidism caused by a unilateral hyperplastic nodule in cats.