# Dolasetron: veterinary dose and monograph

> Dolasetron is a veterinary antiemetic. A 5-HT3 (serotonin) receptor-antagonist ANTIEMETIC — like ondansetron — used for moderate-to-severe vomiting, particularly chemotherapy-induced nausea/vomiting and the refractory vomiting of parvoviral enteritis, pancreatitis or other GI… Indications include chemotherapy-induced nausea and vomiting; refractory vomiting — parvoviral enteritis, pancreatitis, gastroenteritis; peri-operative / drug-induced nausea and vomiting. This monograph lists 2 reference doses for dogs and cats, each with route, frequency and source.

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

## At a glance

- **Drug class:** Antiemetic
- **Also known as:** Anzemet, Dolasetron mesylate
- **Species with doses:** Dogs and Cats
- **General dose range:** 0.5–1 mg/kg IV q24h — check the species tables for the indication
- **Routes:** IV
- **Last reviewed:** 1 October 2026

## Indications

- Chemotherapy-induced nausea and vomiting
- Refractory vomiting — parvoviral enteritis, pancreatitis, gastroenteritis
- Peri-operative / drug-induced nausea and vomiting
- Antiemesis where a once-daily 5-HT3 antagonist is convenient

## Dolasetron 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

*Dolasetron doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Moderate–severe vomiting (incl. chemo/parvo) | 0.6–1 mg/kg | IV | q12–24h | — |

- Moderate–severe vomiting (incl. chemo/parvo): Papich 5e: prevention 0.6 mg/kg IV, SC or PO q12–24h (or 1.2 mg/kg once); treatment 1 mg/kg IV or PO once daily — oral absorption is low. Plumb’s p.434: 0.6 mg/kg IV once daily for chemotherapy (Dowling); 0.5 mg/kg PO, SC or IV q24h (Encarnacion); 0.6–1 mg/kg PO q12h (Washabau).

### Cats

*Dolasetron doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Moderate–severe vomiting | 0.6–1 mg/kg | IV | q12–24h | — |

- Moderate–severe vomiting: Papich 5e (dogs and cats): prevention 0.6 mg/kg q12–24h; treatment 1 mg/kg once daily IV or PO. Plumb’s p.434: 0.6 mg/kg IV q12–24h; 0.6–1 mg/kg PO q12h (Encarnacion; Washabau).

## Contraindications

Known hypersensitivity to 5-HT3 antagonists. Significant cardiac conduction disease / marked QT prolongation (high IV doses prolong QT). GI obstruction (treat the cause, not just the vomiting). Caution with other QT-prolonging or serotonergic drugs.

## Adverse effects

- Generally well tolerated
- Constipation, mild sedation
- QT prolongation / cardiac conduction effects at high IV doses
- Injection-site discomfort

## Drug interactions

- Other QT-prolonging drugs: additive QT prolongation (caution, especially high IV doses)
- Serotonergic drugs: theoretical serotonin-related interaction
- Maropitant/ondansetron: combined for refractory vomiting (different/overlapping mechanisms)

## Pregnancy and lactation

Limited data; use if clearly needed for significant vomiting.

## Monitoring

- Antiemetic response (control of vomiting)
- Constipation; ECG if high IV doses or cardiac risk
- Address the underlying cause of vomiting (not just symptom control)

## Toxicity and overdose

Wide margin; overdose causes constipation and, at high IV doses, dose-related QT prolongation and cardiac-conduction effects (the reason the high-dose human formulation was restricted). Generally well tolerated at antiemetic doses.

Management: No specific antidote. Supportive care; ECG monitoring for QT/conduction effects at high doses; manage constipation. Effects are generally mild. Decontaminate large recent oral ingestions.

## Clinical pearls

- A once-daily 5-HT3 antiemetic (ondansetron-class) — handy for chemotherapy- and GI-injury-induced vomiting (parvo, pancreatitis), often combined with maropitant for refractory cases
- Its long-acting active metabolite allows convenient once-daily dosing
- At high IV doses it can prolong QT — use cautiously in cardiac patients/with other QT-prolonging drugs
- Treat the underlying cause; 5-HT3 antagonists control the symptom

## Mechanism of action

Dolasetron (via its active metabolite hydrodolasetron) selectively antagonises serotonin 5-HT3 receptors on vagal afferent nerves in the GI tract and in the chemoreceptor trigger zone/vomiting centre — blocking the serotonin-mediated emetic signalling that is especially important in chemotherapy- and GI-injury-induced vomiting. The long half-life of the active metabolite permits once-daily dosing.

## Formulations and products

- Injection 20 mg/mL
- 50 / 100 mg tablet
- Anzemet / Dolasetron — 20 mg/mL injection; 50 / 100 mg tablet, Injection / tablet (human-label)

## Storage

Injection/tablets: 15–30 °C, protect from light.

## 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.

## Other antiemetics

- [Maropitant](https://vetmasterji.com/drugs/maropitant)
- [Ondansetron](https://vetmasterji.com/drugs/ondansetron)

## Frequently asked questions

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

Reference doses for Dolasetron in dogs: 0.6–1 mg/kg IV q12–24h (Moderate–severe vomiting (incl. chemo/parvo)). Confirm against the label and the patient before use.

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

Reference doses for Dolasetron in cats: 0.6–1 mg/kg IV q12–24h (Moderate–severe vomiting). Confirm against the label and the patient before use.

### When should Dolasetron not be used?

Known hypersensitivity to 5-HT3 antagonists. Significant cardiac conduction disease / marked QT prolongation (high IV doses prolong QT). GI obstruction (treat the cause, not just the vomiting). Caution with other QT-prolonging or serotonergic drugs.

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

Generally well tolerated; Constipation, mild sedation; QT prolongation / cardiac conduction effects at high IV doses; Injection-site discomfort.

## 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.