# Vinblastine: veterinary dose and monograph

> Vinblastine is a veterinary drug. A vinca-alkaloid CHEMOTHERAPY agent dosed by BODY SURFACE AREA (mg/m²) — closely related to vincristine but with a DIFFERENT toxicity balance: vinblastine is MORE MYELOSUPPRESSIVE and LESS neurotoxic than vincristine. Indications include mast cell tumours (with prednisolone, ± lomustine) — a common first-line medical protocol; lymphoma and some other tumours (per protocol); vinca-sensitive neoplasia where a more myelosuppressive/less-neurotoxic vinca is preferred. This monograph lists 2 reference doses for dogs and cats, each with route, frequency and source.

Source: https://vetmasterji.com/drugs/vinblastine · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Velban, Vinblastine sulphate, Vinblastin
- **Species with doses:** Dogs and Cats
- **Routes:** IV
- **Last reviewed:** 1 October 2026

## Indications

- Mast cell tumours (with prednisolone, ± lomustine) — a common first-line medical protocol
- Lymphoma and some other tumours (per protocol)
- Vinca-sensitive neoplasia where a more myelosuppressive/less-neurotoxic vinca is preferred

## Vinblastine dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Vinblastine doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Mast cell tumour / neoplasia (BSA dosing) | 2–2.2 mg/m² IV (slow) every 1–2 weeks, per protocol | IV | every 1–2 weeks (per protocol) | — |

- Mast cell tumour / neoplasia (BSA dosing): Dosed by BODY SURFACE AREA. Papich 5e: 2 mg/m² IV slow infusion once weekly (higher doses discussed in the monograph). Plumb’s p.1166: 2–2.2 mg/m² IV every 1–2 weeks, often with prednisolone ± cyclophosphamide. Neutrophil nadir about 7 days — CBC before each dose. VESICANT.

### Cats

*Vinblastine doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Neoplasia (BSA dosing) | 2 mg/m² IV (slow) weekly or every 2 weeks, per protocol | IV | every 1–2 weeks (per protocol) | — |

- Neoplasia (BSA dosing): Papich 5e and Plumb’s p.1166 (dogs/cats): 2–2.2 mg/m² IV every 1–2 weeks. Calculate BSA carefully in small patients; vesicant.

## Contraindications

Pre-existing significant myelosuppression (neutropenia). Severe hepatic impairment (hepatic clearance — reduce dose). Perivascular administration (vesicant — necrosis). Pregnancy. Known hypersensitivity. Intrathecal use is FATAL (IV only). Cytotoxic-handling precautions required.

## Species-specific warnings

> **Caution:** Cats: Small body size makes BSA dosing error-prone — calculate carefully and monitor CBC for myelosuppression.

## Adverse effects

- Myelosuppression (neutropenia nadir ~7 days) — dose-limiting (more than vincristine)
- GI: vomiting, diarrhoea, anorexia; ileus/constipation
- Peripheral neuropathy (LESS than vincristine)
- Severe tissue necrosis if EXTRAVASATED (vesicant); alopecia

## Drug interactions

- Other myelosuppressive chemo: additive marrow suppression (built into protocols)
- CYP3A inhibitors (azoles, macrolides): raise vinblastine levels → increased toxicity
- Drugs causing neuropathy: additive (less relevant than with vincristine)
- Combined with prednisolone/lomustine in mast cell tumour protocols

## Pregnancy and lactation

Contraindicated in pregnancy (teratogenic/cytotoxic). Full cytotoxic-handling precautions; pregnant staff must not handle.

## Monitoring

- CBC before each dose (neutrophil nadir ~7 days) — the dose-limiting effect
- IV catheter placement/patency (vesicant) and the site during/after
- GI signs and (less commonly) neuropathy
- Tumour response; cumulative protocol tracking

## Toxicity and overdose

The dose-limiting toxicity is MYELOSUPPRESSION (neutropenia, more pronounced than with vincristine), plus GI toxicity; peripheral neuropathy occurs but LESS than with vincristine. EXTRAVASATION causes severe, progressive tissue necrosis. Accidental intrathecal administration is fatal. Overdose intensifies marrow and GI toxicity.

Management: No specific antidote. Supportive/intensive care: manage neutropenic sepsis (antibiotics ± G-CSF), GI support, and neuropathy. For EXTRAVASATION: stop, aspirate, apply WARM compresses and consider hyaluronidase infiltration (as for vincristine; do NOT use cold). Monitor CBC closely; guarded prognosis in severe overdose.

## Clinical pearls

- The "myelosuppressive, less-neurotoxic" vinca — the mirror image of vincristine; a mainstay (with prednisolone ± lomustine) for canine MAST CELL TUMOURS
- Dose by BSA (mg/m²) and check the CBC before every dose — neutropenia (nadir ~7 days) is the dose-limiter
- A potent VESICANT — a flawless single-stick IV is essential; extravasation → warm compress + hyaluronidase (same as vincristine)
- Watch CYP3A inhibitors (azoles/macrolides), which raise levels/toxicity; handle with full cytotoxic precautions

## Mechanism of action

Binds tubulin and inhibits microtubule polymerisation, arresting the mitotic spindle in metaphase so dividing cells cannot complete mitosis and undergo apoptosis — cell-cycle (M-phase) specific cytotoxicity (same mechanism as vincristine). Subtle differences in tissue distribution/binding give vinblastine a MORE myelosuppressive and LESS neurotoxic profile than vincristine, which guides which vinca is chosen for a given protocol.

## Formulations and products

- Injection 1 mg/mL (10 mg vial)
- Velban / Vinblastine — 1 mg/mL (10 mg vial), Injection (human-label)

## Storage

Injection: REFRIGERATE (2–8 °C), protect from light. Handle as a hazardous cytotoxic (closed-system/PPE); dispose appropriately.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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## Frequently asked questions

### What is the dose of Vinblastine for dogs?

Reference doses for Vinblastine in dogs: 2–2.2 mg/m² IV (slow) every 1–2 weeks, per protocol IV every 1–2 weeks (per protocol) (Mast cell tumour / neoplasia (BSA dosing)). Confirm against the label and the patient before use.

### What is the dose of Vinblastine for cats?

Reference doses for Vinblastine in cats: 2 mg/m² IV (slow) weekly or every 2 weeks, per protocol IV every 1–2 weeks (per protocol) (Neoplasia (BSA dosing)). Confirm against the label and the patient before use.

### When should Vinblastine not be used?

Pre-existing significant myelosuppression (neutropenia). Severe hepatic impairment (hepatic clearance — reduce dose). Perivascular administration (vesicant — necrosis). Pregnancy. Known hypersensitivity. Intrathecal use is FATAL (IV only). Cytotoxic-handling precautions required.

### What are the side effects of Vinblastine in animals?

Myelosuppression (neutropenia nadir ~7 days) — dose-limiting (more than vincristine); GI: vomiting, diarrhoea, anorexia; ileus/constipation; Peripheral neuropathy (LESS than vincristine); Severe tissue necrosis if EXTRAVASATED (vesicant); alopecia.

## Sources

- Plumb's Veterinary Drug Handbook
- Merck Veterinary Manual, 11th edition
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.