# Clopidogrel: veterinary dose and monograph

> Clopidogrel is a veterinary drug. Thienopyridine antiplatelet agent — irreversibly blocks the platelet P2Y12 ADP receptor, reducing platelet aggregation. Indications include feline arterial thromboembolism prophylaxis (cardiomyopathy, atrial enlargement); canine thromboprophylaxis (IMHA, PLN, hypercoagulable states). This monograph lists 3 reference doses for dogs, cats and horses, each with route, frequency and source.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Plavix
- **Species with doses:** Dogs, Cats and Horses
- **General dose range:** 1–4 mg/kg PO q24h — check the species tables for the indication
- **Routes:** PO
- **Last reviewed:** 1 October 2026

## Indications

- Feline arterial thromboembolism prophylaxis (cardiomyopathy, atrial enlargement)
- Canine thromboprophylaxis (IMHA, PLN, hypercoagulable states)

## Clopidogrel 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

*Clopidogrel doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Thromboprophylaxis (IMHA / PLN) | 1–3 mg/kg | PO | q24h | — |

- Thromboprophylaxis (IMHA / PLN): Papich 5e: 2 mg/kg q24h PO; an oral loading dose of 2–4 mg/kg (occasionally 10 mg/kg) followed by 1–2 mg/kg q24h. Plumb’s p.303 (Brainard 2008): 1–3 mg/kg PO once daily, or 0.5–1 mg/kg when combined with aspirin.

### Cats

*Clopidogrel doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Arterial thromboembolism prophylaxis | 18.75 mg/cat | PO | q24h | — |

- Arterial thromboembolism prophylaxis: Papich 5e and Plumb’s p.303 (Hogan 2006): 18.75 mg per cat (¼ of a 75 mg tablet) once daily; bitter — put fragments in gelatin capsules or give with food. Plumb’s also lists 1–3 mg/kg once daily, or 0.5–1 mg/kg with aspirin (Brainard 2008).

### Horses

*Clopidogrel doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Antiplatelet therapy | 2–4 mg/kg | PO | load 4 mg/kg, then 2 mg/kg q24h | — |

- Antiplatelet therapy: Papich 5e: horses — loading dose 4 mg/kg followed by 2 mg/kg q24h PO.

## Contraindications

Active haemorrhage. Discontinue ~5–7 days before elective surgery (irreversible platelet effect). Caution with other antithrombotics / NSAIDs (additive bleeding).

## Adverse effects

- Bleeding / bruising (usually mild)
- Vomiting, inappetence; bitter taste (hypersalivation in cats)

## Drug interactions

- NSAIDs / aspirin / other antiplatelets / anticoagulants: additive bleeding risk
- Proton-pump inhibitors (omeprazole): may reduce conversion to the active metabolite (significance less defined in cats)
- Strong CYP2C19 / CYP3A modulators: altered activation of the prodrug

## Pregnancy and lactation

Safety not established in pregnancy / lactation — avoid unless clearly indicated.

## Monitoring

- Signs of bleeding / bruising; PCV if haemorrhage suspected
- Discontinue 5–7 days before elective surgery
- Limb perfusion / femoral pulses in at-risk cardiomyopathy cats

## Toxicity and overdose

Overdose prolongs bleeding time; spontaneous or trauma-related haemorrhage is the principal risk.

Management: No specific antidote and the platelet effect is irreversible — platelet transfusion is required for serious bleeding. Otherwise supportive: control haemorrhage, IV fluids, monitor PCV.

## Clinical pearls

- First-line over aspirin for the at-risk cardiomyopathy cat — the FAT CAT trial showed longer time to thromboembolism / death
- Quarter-tablet dosing is bitter — give in food or a gel cap to avoid hypersalivation and refusal
- Stop 5–7 days before elective surgery; the platelet inhibition is irreversible for the platelet’s lifespan

## Mechanism of action

Thienopyridine prodrug. Its active metabolite irreversibly blocks the platelet P2Y12 ADP receptor, preventing ADP-mediated activation of the GPIIb/IIIa complex and thus platelet aggregation for the platelet’s ~7–10-day lifespan.

## Formulations and products

- Clopidogrel 75 mg tablet
- Plavix — 75 mg, Tablet (human-label)
- Clopilet — 75 / 150 mg, Tablet (human-label)
- Deplatt — 75 / 150 mg, Tablet (human-label)

## Storage

Store at 15–30 °C, dry.

## 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 Clopidogrel for dogs?

Reference doses for Clopidogrel in dogs: 1–3 mg/kg PO q24h (Thromboprophylaxis (IMHA / PLN)). Confirm against the label and the patient before use.

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

Reference doses for Clopidogrel in cats: 18.75 mg/cat PO q24h (Arterial thromboembolism prophylaxis). Confirm against the label and the patient before use.

### What is the dose of Clopidogrel for horses?

Reference doses for Clopidogrel in horses: 2–4 mg/kg PO load 4 mg/kg, then 2 mg/kg q24h (Antiplatelet therapy). Confirm against the label and the patient before use.

### When should Clopidogrel not be used?

Active haemorrhage. Discontinue ~5–7 days before elective surgery (irreversible platelet effect). Caution with other antithrombotics / NSAIDs (additive bleeding).

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

Bleeding / bruising (usually mild); Vomiting, inappetence; bitter taste (hypersalivation in cats).

## Sources

- Plumb's Veterinary Drug Handbook
- AAFP guidelines
- 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.