Hyaluronate Sodium
Hyaluronate sodium (often referred to as hyaluronic acid or HA) is a naturally occurring, high-viscosity mucopolysaccharide found abundantly in the connective tissues, synovial fluid, umbilical cord, and the vitreous humor of the eye. In veterinary medicine, it is primarily utilized for the management of synovitis and osteoarthritis, particularly when not associated with severe degenerative joint disease or full-thickness cartilage loss. **Key Clinical Points:** * **Molecular Weight (MW) Variations:** Commercially available products vary significantly in molecular weight. High MW products (>1x10^6) are often preferred when synovial adhesions and pannus formation need to be avoided (e.g., post-surgical fragment removal), as they inhibit the proliferation of synovial fibroblasts. Low MW products are generally less expensive and can also effectively ameliorate signs of joint disease. * **Source:** Many commercial veterinary HA products are derived from rooster combs, though bio-fermentation sources exist. * **Administration:** Primarily administered via intra-articular (IA) or intravenous (IV) injection, though oral gel formulations have shown efficacy in reducing post-operative joint effusion in horses.
Mechanism: Hyaluronate sodium provides both mechanical and pharmacological benefits to the diseased joint: * **Mechanical Support:** Restores the viscoelastic properties of synovial fluid, providing a cushioning effect and boundary lubrication for articular cartilage. * **Anti-inflammatory Pathway:** * **Free Radicals** โ Scavenged directly by HA molecules, reducing oxidative damage within the joint capsule. * **Prostaglandins** โ Synthesis and release are suppressed, mitigating local inflammation and pain. * **Cellular Modulation:** Reduces the influx of inflammatory proteins and leukocytes into the joint space. Interacts with **CD44 receptors** on synoviocytes and macrophages to downregulate pro-inflammatory cytokines.
Dosing by species
- Keratoconjunctivitis sicca (dry eye) or corneal ulceration ยท 1-2 drops per eye ยท Topical ยท q4h to q12h (or as needed) ยท As needed ยท Frequency depends on the severity of the condition and the viscosity of the product.
- Ocular lubrication / corneal ulceration ยท 1 drop per eye ยท Topical ยท q4h to q12h ยท As needed ยท Frequency depends on the severity of the condition.
- Osteoarthritis / Synovitis (Hylartin-V, Hyvisc, Hyalovet) ยท 20 mg ยท IA ยท As directed ยท Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Equron) ยท 10 mg ยท IA ยท As directed ยท Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Synacid) ยท 50 mg ยท IA ยท As directed ยท Check individual product label for specific dosing.
- Osteoarthritis / Synovitis (Legend) ยท 40 mg IV or 20 mg IA ยท IV/IA ยท As directed ยท Check individual product label for specific dosing.
- Reduce joint effusion post-arthroscopic surgery for osteochondritis dissecans (OCD) ยท 100 mg ยท PO ยท once daily ยท 30 days ยท Administered as an oral gel (Conquer)
- Ocular lubrication / corneal trauma ยท 1 drop per eye ยท Topical ยท q6h to q12h ยท As needed ยท Use with care to avoid stressing the bird during frequent handling.
Routes of administration
Contraindications
- Injection through skin that has been recently fired or blistered
- Injection through skin with excessive scurf or counterirritants
- Use as a substitute for adequate diagnosis (e.g., failing to rule out fractures via radiography)
- Hypersensitivity to hyaluronate or any component of the formulation
Adverse effects
- Local joint flare (heat, swelling, and/or effusion) post-injection
- Increased incidence of flares when combined with other intra-articular drugs
- Mild transient ocular irritation (rare)
- Temporary blurred vision immediately after application (especially with higher viscosity gels)
Monitoring
- Resolution of clinical signs (lameness, joint effusion)
- Injection site for signs of local reaction (heat, swelling, pain) within 24-96 hours post-injection
- Resolution of clinical signs (e.g., blepharospasm, conjunctival hyperemia)
- Corneal ulcer healing via fluorescein staining
- Schirmer tear test (STT) for dry eye management
Overdose
Acute toxicology studies performed in horses have demonstrated no systemic toxicity associated with overdoses.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.