Thyroid (T4) testing explained
Thyroid disease runs opposite in dogs and cats: dogs get hypothyroidism (low T4), cats get hyperthyroidism (high T4). T4 is the first screening step; abnormal results usually need a recheck or free T4/TSH.
🧾 Antes de la prueba
- ✓No fasting needed
- ✓Mention medications that can affect the result
📊 Cómo leer los valores clave
| Buscar | Alto | Bajo |
|---|---|---|
| Dog T4 | Rare (thyroid tumor or over-supplementation) | Hypothyroidism: weight gain, symmetrical hair loss, low energy — but non-thyroid illness also lowers T4, confirm with free T4/TSH |
| Cat T4 | Hyperthyroidism: ravenous appetite with weight loss, vomiting, fast heart — the core senior-cat screen | Rare |
💡 Cómo interpretarlo A single low T4 in a dog is not proof of hypothyroidism (other illness falsely lowers it). A raised T4 in a cat largely confirms hyperthyroidism. Both are treatable with good long-term outlooks.
🤖 Interpretación IA del informe
Escribe los valores de tu informe abajo (p. ej. «ALT 250, BUN 40») y la IA los interpretará según el significado de cada prueba.
Preguntas frecuentes
Is hypothyroid medication lifelong?
Usually yes. Levothyroxine is inexpensive; after dose adjustments most dogs do very well.
How is feline hyperthyroidism treated?
Four options: anti-thyroid drugs, prescription iodine-restricted food, radioactive iodine therapy (curative), or surgery. Discuss trade-offs with your vet.