Hyperthyroidism in Cats: Four Paths to Euthyroid

Learning Objectives

• 1Recall the diagnostic criteria for feline hyperthyroidism including T4 thresholds, clinical signs, and when to pursue free T4 or scintigraphy
• 2Explain the concept of 'unmasking CKD' when treating hyperthyroidism and describe the recommended monitoring protocol for renal function post-treatment
• 3Compare and contrast the four primary treatment options — methimazole, radioactive iodine (I-131), thyroidectomy, and iodine-restricted diet — including efficacy, risk profile, cost, and quality-of-life implications
• 4Given a patient case, select the most appropriate treatment modality based on concurrent disease, owner constraints, and clinic capabilities
• 5Assess the evidence for integrative adjuncts — including hepatoprotectants, adaptogens, cardiac support nutraceuticals, and acupuncture — and determine when each is appropriate in the hyperthyroid cat

Course Syllabus

1. 1
   Meet Biscuit — The Opening CasePreview

   Opening case: the classic versus apathetic presentation of feline hyperthyroidism, why a T4 is never run alone, and how a reassuring number can still be lying.

   9 min
2. 2
   The Reversible Trial — Methimazole & the Kidney

   Methimazole controls but does not cure. Starting dose as a floor rather than a target, the follow-up appointment that matters most, reading a rising creatinine for what it is, and the adverse-effect flags worth knowing.

   8 min
3. 3
   Diet, Dosing & Monitoring

   Iodine-restricted diet as therapy, why it only works when it is the only thing she eats, compliance as the drug, the monitoring rhythm, and aiming for a sweet spot rather than the floor.

   4 min
4. 4
   The Cure — Radioiodine & Surgery

   The two treatments that end the disease: radioiodine as standard of care and thyroidectomy as the alternative — practical constraints, the post-operative calcium crash, and why the reversible trial is the gate.

   4 min
5. 5
   The Heart, the Pressure & Concurrent Disease

   Never just the thyroid: hormone-driven cardiac change that reverses with treatment versus disease that was never the thyroid's, hypertension that appears after treatment, retinal signs, and reading four values in balance.

   8 min
6. 6
   Biscuit at Six Months — Putting It Together

   Biscuit six months on: expected post-treatment renal change framed as a decision rather than a complication, quality of life alongside quantity, the cure conversation with a senior cat, and screening every cat over ten.

   8 min