Evaluation of Thyroid Function
Normal Thyroid Hormone Values
|
Species |
Total T4(nmol/L) |
Total T3(nmol/L) |
Free T4by dialysis (pmol/L) |
TSH(ng/ml) |
Post-pill T4"Ideal range" |
T4 forcat on tapazole |
| Dog |
20 - 55 12 - 19, borderline |
0.7 - 2.3 |
15 - 45 10-14, borderline |
below 0.50 | 30 - 60 | |
| Cat | 10 - 50 | 0.4 - 2.3 | 10 - 48 | 30 - 60 | 10 - 25 | |
| Horse | 10 - 50 | 0.4 - 1.5 | 20 - 50 | |||
| Ferret | 10 - 50 | 0.7 - 2.1 |
- Total T4 or T3 by RIA. Sample collection: send 1 ml of serum. One ml sufficient for both tests. Ship samples in plastic vial. No cooling needed. Free T4 can be assayed using this sample if needed.
- Free T4 by Equilibrium dialysis. Sample collection: For dogs or cats, send 1 ml of serum (not plasma). Ship sample in plastic vial without refrigeration. No cooling needed unless sample will be stored for more than 3 days before shipping. Total T4 or T3 can also be run on this sample if desired.
- Post-pill thyroid testing. Collect 1 ml of serum or plasma 4 to 12 hours after dose of thyroid medication. Please indicate exact interval on submission forms. Normally, we recommend measuring only total T4 in this sample. Ship as for total T4.
- Canine TSH assay. Collect 1 ml of serum (not plasma). Ship sample in insulated container with cold pack. The TSH value should be above normal in dogs with primary hypothyroidism. Primary hypothyroidism is by far the most common cause of hypothyroidism in dogs.
