Marbofloxacin

Marbofloxacin is a veterinary fluoroquinolone antibacterial used for susceptible infections in companion animals and, with corresponding products, livestock. Its spectrum emphasizes aerobic gram-negative organisms and selected staphylococci. Clinical applications include skin, urinary and respiratory infections, with additional use against some intracellular organisms and species-specific livestock diseases.

Group

Veterinary fluoroquinolone antibacterial

Mechanism of Action

Marbofloxacin inhibits bacterial DNA gyrase and topoisomerase IV, disrupting DNA replication, chromosome organization and separation of daughter chromosomes. Stabilization of enzyme–DNA cleavage complexes causes lethal DNA damage in susceptible organisms. Its effect is concentration dependent and can persist after concentrations decline. Organism-specific susceptibility determines the useful clinical spectrum.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Susceptible bacterial infection	2.75–5.5 mg/kg	PO	Every 24 h
Pyoderma	2 mg/kg	PO	Every 24 h	Separate lower-dose clinical regimen described in the reported guidance.
Pseudomonas otitis with deep involvement	5.5 mg/kg	PO	Every 24 h	Up to 30 days; For susceptible infection with otitis media, ulceration or deep inflammatory disease; reevaluate if no improvement in 5 days.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Susceptible bacterial infection	2.75–5.5 mg/kg	PO	Every 24 h
Mycoplasma haemofelis infection	2.75 mg/kg	PO	Every 24 h	Up to 14 days
Selected localized mycobacterial infection	2 mg/kg	PO	Every 24 h	Not effective against Mycobacterium avium complex; organism identification and zoonotic assessment are required.

Horses

Use / stage	Dose	Route	Schedule	Instructions
Susceptible gram-negative infection	2 mg/kg	IV, PO	Every 24 h	Oral absorption is lower than in small animals; this regimen may not cover less susceptible gram-positive organisms.

Cattle

Use / stage	Dose	Route	Schedule	Instructions
Calf respiratory disease	2 mg/kg	IV, SC, IM	Every 24 h	Up to 5 days; Calves; 3-5-day course. Use neck injection sites where applicable.
Calf respiratory disease	8–10 mg/kg	IM	Once	Separate single-injection calf regimen.

Pigs

Use / stage	Dose	Route	Schedule	Instructions
Susceptible bacterial infection	2 mg/kg	IM	Every 24 h	Up to 5 days; Inject in the neck for 3-5 days.

Reptiles

Use / stage	Dose	Route	Schedule	Instructions
Ball-python susceptible bacterial infection	10 mg/kg	PO	Every 48 h	Ball pythons only; pharmacokinetic study with limited clinical safety/efficacy evidence.

Indications

Treatment of susceptible bacterial skin and soft-tissue infections in dogs and cats.
Treatment of selected susceptible urinary tract or respiratory infections in companion animals.
Treatment of selected feline hemoplasma infections caused by susceptible organisms, with variable clearance of infection.
Treatment of bovine respiratory disease with a corresponding veterinary product.
Treatment of selected swine respiratory infections or mastitis–metritis–agalactia syndrome with an indicated formulation.
Treatment of selected susceptible bacterial bone or other deep-tissue infections within an appropriate antimicrobial plan.

Contraindications

Growing animals with cartilage-injury risk
Use cautiously with seizure disorders.

Interactions

Oral metal cations reduce absorption.
Some fluoroquinolones can increase theophylline concentrations; veterinary interaction evidence is limited.

Adverse effects

Vomiting, diarrhoea and central nervous system effects
Juvenile articular cartilage injury

Toxicity

Stop treatment for serious neurologic or gastrointestinal reactions and provide supportive care.

Preparations

Preparation	Form	Strength	Route
Marbofloxacin 25 mg tablet	Tablet	25 mg / tablet	PO
Marbofloxacin 50 mg tablet	Tablet	50 mg / tablet	PO
Marbofloxacin 100 mg tablet	Tablet	100 mg / tablet	PO
Marbofloxacin 200 mg tablet	Tablet	200 mg / tablet	PO
Marbofloxacin 100 mg/mL injection	Injection	100 mg / mL	IV, SC, IM
Forcyl marbofloxacin 160 mg/mL injection	Injection	160 mg / mL	IV, IM
Marbomet 50 mg tablet	Tablet	50 mg / tablet	PO

Monitoring and Administration

Select treatment using susceptibility results when available.

Avoid mineral-containing admixtures. Give livestock injections in the neck when specified.

Guidance prohibits extralabel fluoroquinolone use in food animals in the United States; do not apply foreign withdrawal periods as universal local instructions.

Pig single-dose alternative: 8 mg/kg once. The route is not restated in that reported instruction; it is not assigned automatically.

For the described dog/cat oral label regimen, continue skin/soft-tissue treatment 2-3 days beyond clinical resolution and urinary infection treatment for at least 10 days, with maximum 30 days. Reevaluate diagnosis if no improvement after 5 days. These durations do not apply automatically to every infection.