| Radioiodine (I-131) | Hill's Rx y/d Diet (severely iodine deficient) | Methimazole | |
|---|---|---|---|
| OUTCOME | Cures hyperthyroid state | Hyperthyroidism is never cured | Hyperthyroidism is never cured |
| SIDE EFFECTS | None | Unknown | Common |
| COSTS | One time | Ongoing for the life of the cat | Ongoing for the life of the cat |
| CONCURRENT DISEASE | Diet flexible to accommodate other needs | Strict adherence to Y/D diet required | Diet flexible to accommodate other needs |
| TREATMENT | Single SQ injection | Life-long diet | Life-long treatment |
| HYPOTHYROIDISM | Rare with customized I-131 dosing | Unknown | Common |
| FOLLOW UP CARE | Routine | Continuous | Continuous |
| MULTI-CAT HOUSEHOLDS | No impact | Requires independent feeding of hyperthyroid patient | No impact |
| ADENOMA | Destroys adenoma | Adenoma continues to grow leading to possible loss of control | Adenoma continues to grow requiring regular dose adjustments |
| MALIGNANT TRANSFORMATION | Prevents malignant transformation | Malignant transformation not prevented | Malignant transformation not prevented |
| CARCINOMA | Only effective treatment for cats with thyroid carcinoma | Allows thyroid carcinoma to progress | Allows thyroid carcinoma to progress |
| HYPERTENSION | Renal hypertension and proteinuria resolve | glomerular hypertension and proteinuria may persist | Renal hypertension and proteinuria may persist |
| RENAL DISEASE | Stops progression | Poor control may allow progression | Poor control may allow progression |
| DIET | Variable Diet | Strict diet adherence required | Variable Diet |
| OBLIGATE CARNIVORE | Meat based diets allowed | High carbohydrate diet inappropriate for obligate carnivore | Meat based diets allowed |
| SURVIVAL | Best long term survival | Survival unproven | Shortest survival |