SAA — Serum Amyloid A (Feline)¶
1. What is SAA?¶
Serum amyloid A (SAA) is the major acute-phase protein in cats, rising more rapidly and to higher multiples than in dogs. It is the most sensitive early marker of feline inflammation and rises within 3–6 hours of an inflammatory stimulus.
2. Data Card¶
| Field | Value |
|---|---|
| Biomarker | SAA (Serum Amyloid A) |
| Organ | Systemic — acute-phase reactant |
| Species | Feline |
| Specimen | Serum / Plasma |
| Method | FICT (Fluorescence Immunochromatography) |
| Analyzer | FIA680 / FIA880 |
| Unit | µg/mL |
3. Reference Range (Feline)¶
| SAA (µg/mL) | Interpretation |
|---|---|
| < 5 | Normal |
| 5–20 | Mild inflammation |
| 20–100 | Moderate inflammation |
| > 100 | Severe inflammation / sepsis |
4. Clinical Significance¶
- Early detection: rises within 3–6 h of inflammation — faster than any clinical sign.
- Feline-friendly: reliable where fever is absent (common in cats).
- Treatment monitoring: serial SAA tracks response to antibiotics/therapy.
- Disease screening: elevated in FIP, pancreatitis, trauma, neoplasia, and post-surgery.
5. Analytical Performance (Migibio Assay)¶
| Metric | Value |
|---|---|
| LOD | 0.5 µg/mL |
| LOQ | 1.0 µg/mL |
| Linear range | 1–250 µg/mL |
| Intra-assay CV% | < 8% |
| Inter-assay CV% | < 10% |
6. Interpretation Guide¶
| SAA (µg/mL) | Action |
|---|---|
| < 5 | Normal |
| 5–100 | Inflammatory process — identify source + treat |
| > 100 | Severe — aggressive diagnostics + therapy |
7. FAQ¶
Q1. What does an elevated SAA mean in cats?
An elevated feline serum amyloid A indicates systemic inflammation. SAA is the major acute-phase protein in cats and rises within 3–6 hours — often before clinical signs or fever are apparent.
Q2. How is SAA different from CRP?
Both are acute-phase proteins, but they are species-specific in utility: SAA is the dominant feline acute-phase protein, while CRP is the dominant canine marker. Using the wrong species' marker reduces sensitivity.
Q3. What is the normal SAA range for cats?
The reference range is below 5 µg/mL. Values of 5–20 µg/mL indicate mild inflammation, 20–100 µg/mL moderate, and above 100 µg/mL severe inflammation or sepsis.
Q4. Can SAA diagnose feline infectious peritonitis (FIP)?
SAA is frequently elevated in FIP but is not specific to it — many inflammatory, neoplastic, and traumatic conditions raise SAA. It is used as a supportive marker, not a confirmatory test.
8. References¶
- Kajikawa T, Furuta A, Onishi T, et al. Changes in concentrations of serum amyloid A protein, alpha 1-acid glycoprotein, haptoglobin, and C-reactive protein in feline sera due to induced inflammation and surgery. Vet Immunol Immunopathol. 1999;68(1):91-98. PMID: 10231954
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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.