Human Intravenous Immunoglobulin (hIVIG)
Human Intravenous Immunoglobulin (hIVIG) is a purified blood product used for the treatment of severe immune-mediated diseases in dogs. Efficacy has been demonstrated in immune-mediated thrombocytopenia (IMT) and acute canine polyradiculoneuritis. > **Warning:** Its use in immune-mediated haemolytic anaemia (IMHA) remains controversial. Use should be reserved for exceptional cases where other treatments have failed. **Clinical Pearl:** In cases of IMT, the efficacy of hIVIG is comparable to that achieved with vincristine, providing a rapid rescue therapy by blocking macrophage destruction of platelets.
Mechanism: The drug has both immediate and long-term immunomodulatory effects, though exact mechanisms are not fully elucidated. * **Immediate effects:** Binding to **Fc receptors** on macrophages (preventing phagocytosis of opsonized cells) and providing **anti-idiotype antibodies**. * **Long-term effects:** Reacts with membrane receptors on **T cells**, **B cells**, and **monocytes** → alters immune system autoregulation, reduces autoreactivity, and induces tolerance to self.
Dosing by species
- Severe immune-mediated diseases (e.g., IMT, acute polyradiculoneuritis) · 0.5-1.0 g/kg (Higher doses of up to 2.2 g/kg are used in some studies) · IV · Administered over 6-8 hours · Single infusion · Administer slowly over 6-8 hours.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Patients with increased plasma protein levels (hyperproteinaemia)
Adverse effects
- Anaphylactic reactions (theoretical risk, though not widely recorded in dogs)
Drug interactions
- Highly protein-bound drugs · Use with care due to potential binding displacement or alterations in plasma protein dynamics · moderate
- Vaccines · May interfere with the immune response to vaccination; use with care · moderate
Monitoring
- Plasma protein levels
- Signs of anaphylaxis during infusion
- Clinical signs of immune-mediated disease resolution (e.g., platelet counts)
Overdose
No specific overdose information is provided in the monograph. However, excessive administration may lead to severe hyperproteinaemia, hyperviscosity syndrome, and volume overload.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.