Radioiodine therapy is the gold standard treatment for feline hyperthyroidism, offering a single curative treatment, but requires temporary hospitalisation that creates stress for affected cats.
Radioiodine therapy creates a welfare tradeoff between the stress of mandatory hospitalisation and the welfare benefit of cure. Cats held in isolation facilities for 1-2 weeks experience the sustained stress of confinement in an unfamiliar environment with limited human contact. For cats with significant anxiety or existing stress-related conditions, this period can be particularly welfare-compromising. However, the alternative — daily medication for the remainder of the cat life — carries its own welfare costs including pill-related stress and the risks of under or over-treatment. The welfare calculation generally favours radioiodine for cats who are good candidates, because the brief hospitalisation period is outweighed by years of medication-free wellbeing. Facilities that provide environmental enrichment, appropriate hiding places, and gentle handling during hospitalisation can substantially reduce the welfare cost of the mandatory isolation period.