# Bromhexine: veterinary dose and monograph

> Bromhexine is a veterinary drug. A MUCOLYTIC / secretolytic (Bisolvon) that thins and loosens viscid respiratory mucus, aiding expectoration — used for productive respiratory disease in dogs, cats, horses and food animals (often as an adjunct alongside antibiotics for… Indications include productive bronchitis / pneumonia with viscid mucus (adjunct) — small and large animals; respiratory disease where improving mucus clearance helps (e.g. with antibiotic therapy); enhancement of antibiotic penetration into bronchial secretions (e.g. with oxytetracycline). This monograph lists 5 reference doses for dogs, cats, cattle, horses and pigs, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

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

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Bisolvon, Bromhexine HCl
- **Species with doses:** Dogs, Cats, Cattle, Horses and Pigs
- **General dose range:** 0.5–2 mg/kg PO q12–24h — check the species tables for the indication
- **Routes:** PO, IM
- **Last reviewed:** 1 October 2026

## Indications

- Productive bronchitis / pneumonia with viscid mucus (adjunct) — small and large animals
- Respiratory disease where improving mucus clearance helps (e.g. with antibiotic therapy)
- Enhancement of antibiotic penetration into bronchial secretions (e.g. with oxytetracycline)

## Bromhexine 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

*Bromhexine doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Mucolytic (respiratory) | 0.5–2 mg/kg | PO | q12h | — |

- Mucolytic (respiratory): ~1–2 mg/kg PO q12h (or per product); adjunct to specific therapy. No Papich 5e or Plumb’s monograph — dose from product labelling; follow the local label.

### Cats

*Bromhexine doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Mucolytic (respiratory) | 0.5–1 mg/kg | PO | q12–24h | — |

- Mucolytic (respiratory): ~0.5–1 mg/kg. No Papich 5e or Plumb’s monograph — dose from product labelling; follow the local label.

### Cattle

*Bromhexine doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Respiratory disease (adjunct, enhances antibiotic penetration) | 0.5–1 mg/kg | IM | q24h | — | no slaughter withdrawal |

- Respiratory disease (adjunct, enhances antibiotic penetration): Often combined with antibiotics; observe label withdrawal. No Papich 5e or Plumb’s monograph — dose and withdrawal from product labelling; follow the local label.

### Horses

*Bromhexine doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Respiratory mucolysis | 0.1–0.25 mg/kg | PO | q12h | — |

- Respiratory mucolysis: Adjunct for inflammatory airway disease. No Papich 5e or Plumb’s monograph — dose from product labelling; follow the local label.

### Pigs

*Bromhexine doses for pigs*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Respiratory disease (mucolytic adjunct) | 0.5–1 mg/kg | IM | q24h | — | no slaughter withdrawal |

- Respiratory disease (mucolytic adjunct): No Papich 5e or Plumb’s monograph — dose and withdrawal from product labelling (IM, or in-feed/in-water per product); follow the local label.

### Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

*Bromhexine doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Respiratory disease (adjunct, enhances antibiotic penetration) | 0.5–1 mg/kg | IM | q24h | — | no slaughter withdrawal |

- Respiratory disease (adjunct, enhances antibiotic penetration): Often combined with antibiotics; observe label withdrawal. No Papich 5e or Plumb’s monograph — dose and withdrawal from product labelling; follow the local label.

## Contraindications

Known hypersensitivity. Gastric ulceration (caution — may increase gastric secretion). Otherwise minimal. Address the underlying infection (it is an adjunct, not a primary antimicrobial).

## Adverse effects

- Generally very well tolerated
- Occasional GI upset (nausea/vomiting)
- Rare hypersensitivity

## Drug interactions

- Antibiotics (oxytetracycline, amoxicillin, erythromycin): bromhexine increases their bronchial-secretion levels (a beneficial adjunct effect)
- Antitussives: avoid combining strong cough suppressants with a mucolytic (you want to clear, not retain, mucus)
- No major adverse pharmacokinetic interactions

## Pregnancy and lactation

Considered low-risk; long use record. Use if needed.

## Monitoring

- Respiratory response (easier, more productive cough; resolution of signs)
- GI tolerance
- Ensure the primary cause (infection/inflammation) is being treated

## Toxicity and overdose

Very wide safety margin — overdose typically causes only mild GI upset. No significant organ toxicity at therapeutic or modestly supratherapeutic doses.

Management: Supportive only; no specific antidote needed. Manage GI upset symptomatically.

## Clinical pearls

- A safe, cheap mucolytic adjunct (very common in India) — thins viscid mucus and aids clearance in bronchitis/pneumonia
- Bonus: it boosts the concentration of some antibiotics (e.g. oxytetracycline) in bronchial secretions — a rational pairing
- Don't combine with strong cough SUPPRESSANTS — the goal is to clear mucus, not retain it
- It is an adjunct: treat the underlying infection/inflammation as well (its metabolite is ambroxol)

## Mechanism of action

A secretolytic that depolymerises the acid mucopolysaccharide (mucoprotein) fibres of bronchial mucus, reducing its viscosity, and stimulates serous secretion and ciliary activity — together improving mucociliary clearance and expectoration. It also increases the concentration of certain antibiotics in bronchial secretions/sputum. Its active metabolite is ambroxol (itself a mucolytic).

## Formulations and products

- Syrup 0.8 mg/mL (4 mg/5 mL)
- 8 mg tablet
- Injection / soluble powder (veterinary)
- Bisolvon Vet (Boehringer Ingelheim) — Bromhexine (powder/injection/syrup), Powder / injection / syrup
- Bromhexine (various) — 8 mg tablet; 4 mg/5 mL syrup, Tablet / syrup (human-label)

## Storage

Syrup/tablets/injection: 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.

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## Frequently asked questions

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

Reference doses for Bromhexine in dogs: 0.5–2 mg/kg PO q12h (Mucolytic (respiratory)). Confirm against the label and the patient before use.

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

Reference doses for Bromhexine in cats: 0.5–1 mg/kg PO q12–24h (Mucolytic (respiratory)). Confirm against the label and the patient before use.

### What is the dose of Bromhexine for cattle?

Reference doses for Bromhexine in cattle: 0.5–1 mg/kg IM q24h (Respiratory disease (adjunct, enhances antibiotic penetration)). Confirm against the label and the patient before use.

### What is the withdrawal period for Bromhexine?

Cattle, IM (Respiratory disease (adjunct, enhances antibiotic penetration)): no slaughter withdrawal; Pigs, IM (Respiratory disease (mucolytic adjunct)): no slaughter withdrawal. Follow the product label and national regulations where they differ.

### When should Bromhexine not be used?

Known hypersensitivity. Gastric ulceration (caution — may increase gastric secretion). Otherwise minimal. Address the underlying infection (it is an adjunct, not a primary antimicrobial).

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

Generally very well tolerated; Occasional GI upset (nausea/vomiting); Rare hypersensitivity.

## 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.