Mycobacterial Cell Wall Fraction Immunomodulator
**Mycobacterial cell wall fraction immunomodulator** is a biologic agent used in veterinary medicine to stimulate the patient's immune system against tumors and specific infections. * In **dogs**, it is used as a locally infiltrated injection for the immunotherapy of mixed mammary tumors and mammary adenocarcinomas. * In **horses**, it is utilized for treating sarcoids (local infiltration), Equine Respiratory Disease Complex (ERDC) via IV injection, and equine metritis caused by *Streptococcus zooepidemicus* (IV or intrauterine). > **Clinical Pearl:** Because this is an immunomodulator, its efficacy relies entirely on the patient having a functional immune system. While local (intratumoral) efficacy is documented, systemic efficacy is not as well established.
Mechanism: The drug exerts a non-specific immune stimulatory effect, primarily targeting **cell-mediated immune mechanisms** and **macrophage activation**. * **Macrophage activation** → Release of **Interleukin-1 (IL-1)** → Cascade of immune responses targeting abnormal cells (tumors) or pathogens. * Requires a competent, functional immune system to be effective.
Dosing by species
- Immunotherapy of sarcoids · Dosage varies with tumor size, but 1 mL should be considered a minimum dose. Infiltrate entire tumor and a small region of adjacent and underlying tissue. · Intratumoral · Repeat treatment every 1-3 weeks. · Discontinue if no response after 4 treatments · Large pedunculated sarcoids should be de-bulked by partial excision prior to treatment. Use no larger than a 20-gauge needle. Inject quickly as emulsion separates rapidly.
- Immunotherapeutic agent for the treatment of Equine Respiratory Disease Complex (ERDC) · 1.5 mL (one syringe) · IV · May be repeated in 1-3 weeks · Inject into the jugular vein.
- Aid in the treatment of equine metritis caused by Streptococcus zooepidemicus · 1.5 mL (one syringe) · IV · Once during the early estrus period · Inject into the jugular vein.
- Aid in the treatment of equine metritis caused by Streptococcus zooepidemicus · Dilute 1.5 mL of Settle in sterile LRS, normal saline, water for injection or semen extender to provide a final volume of 25-50 mL. · Intrauterine · Once · Aseptically administer the diluted solution into the uterus using a sterile catheter.
- Immunotherapy of mixed mammary tumor and mammary adenocarcinoma · Dosage varies with tumor size, but 1 mL should be considered a minimum dose. Infiltrate entire tumor and a small region of adjacent and underlying tissue. · Intratumoral · Once, 2-4 weeks before surgery. If surgery is not to be used, repeat treatment every 1-3 weeks. · Discontinue if no response after 4 treatments · Using no larger than a 20-gauge needle. Be certain the emulsion is mixed thoroughly and inject quickly as emulsion can separate rapidly. Additional anesthetics or analgesics may be used for pain.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Prior hypersensitivity to mycobacterial cell wall compounds
- Active mycobacterial infections
Adverse effects
- Transient fever
- Depression or drowsiness
- Decreased appetite
- Localized pain and tenderness at injection site
- Tumor necrosis and draining (expected therapeutic effect but can be an adverse event)
- Hypersensitivity or Anaphylaxis
- Severe respiratory inflammatory reactions (reported in horses)
Drug interactions
- Corticosteroids, ACTH, Immunosuppressive drugs (e.g., cyclosporine) · May reduce the effectiveness of mycobacterial cell wall immunostimulants
Monitoring
- Clinical Efficacy (tumor size, metritis improvement, or respiratory infection improvement)
- Adverse Effects (fever, local reactions, appetite)
Overdose
No information was located regarding overdosage or acute toxicity.
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.