Hormones & Endocrine¶
Test Menu¶
| Test | Primary Use | Species |
|---|---|---|
| T4 (Total) | Thyroid screening | Canine, Feline |
| TSH | Hypothyroidism confirmation | Canine |
| Cortisol | Adrenal (Cushing's/Addison's) | Canine |
| Progesterone | Ovulation timing | Canine |
| Relaxin | Pregnancy confirmation | Canine, Feline |
Reference Ranges¶
| Analyte | Species | Reference Range |
|---|---|---|
| T4 | Canine/Feline | 1.0–4.0 µg/dL |
| TSH | Canine | 0–0.6 ng/mL |
| Cortisol (basal) | Canine | 2–6 µg/dL |
| Progesterone (anestrus) | Canine | 0–2 ng/mL |
| Relaxin (pregnant) | Canine/Feline | > 1.0 ng/mL |
Progesterone — Breeding Management¶
Progesterone is the gold standard for ovulation timing. Serial measurement every 2–3 days tracks the LH surge:
| Progesterone (ng/mL) | Stage |
|---|---|
| < 1 | Anestrus / early proestrus |
| 1–2 | Approaching LH surge |
| 2–5 | Ovulation window (breed/AI) |
| > 5 | Post-ovulation |
Explore This Domain¶
- Thyroid Testing (T4/TSH) — hypothyroidism vs euthyroid sick
- Cortisol Testing — Cushing's and Addison's
- Progesterone & Relaxin — ovulation timing and pregnancy
FAQ¶
Why test T4 and TSH together? To differentiate primary hypothyroidism (low T4 + high TSH) from euthyroid sick syndrome (low T4 + normal TSH).
When should I start progesterone testing? Day 5–7 of estrus, then every 2–3 days until ovulation.
How early can relaxin confirm pregnancy? From ~day 21–28 post-mating.
For assay validation data, see the Research Center.
Authored by: Migibio Clinical & Scientific Affairs, Guangzhou Magic Biotech Co., Ltd.
Reviewed by: Migibio R&D Quality Committee
Last updated: 2026-08-13
Disclosure: Migibio (Guangzhou Magic Biotech Co., Ltd.) is the manufacturer of the FIA680/FIA880 analyzers and FICT reagents referenced in this content. See our Editorial & Review Policy.