Vetdrugs 2.0Gatifloxacin is a fluoroquinolone antibacterial used extra-label in veterinary ophthalmology. Ophthalmic solutions provide local treatment of susceptible bacterial ocular-surface infections, including selected corneal infections. Its activity spans selected gram-positive and gram-negative organisms, with clinical suitability determined by the organism and ocular disease involved.
Group
Fluoroquinolone antibacterial
Mechanism of Action
Gatifloxacin inhibits bacterial DNA gyrase and topoisomerase IV, enzymes that control DNA supercoiling and separation of replicated chromosomes. Stabilization of disrupted enzyme–DNA complexes impairs replication, transcription and repair and produces bactericidal activity. Ophthalmic delivery provides local drug exposure, while organism-specific target changes or other resistance mechanisms can reduce susceptibility.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bacterial ocular infection | Reference only | TOPICAL | Sterile gatifloxacin eye drops; instillation quantity and frequency depend on the ocular diagnosis. No complete veterinary schedule was verified for this entry. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bacterial ocular infection | Reference only | TOPICAL | Sterile gatifloxacin eye drops; instillation quantity and frequency depend on the ocular diagnosis. No complete veterinary schedule was verified for this entry. |
Indications
- Local treatment of susceptible bacterial conjunctivitis in dogs, cats or other veterinary patients.
- Treatment of selected susceptible bacterial keratitis or infected corneal ulcers with an ophthalmic preparation, supported by organism-specific susceptibility and ocular assessment.
Contraindications
- Quinolone hypersensitivity
Adverse effects
- Local irritation
- Hypersensitivity
- Possible epithelial toxicity with intensive topical exposure
Toxicity
Discontinue if significant irritation or hypersensitivity develops. Ophthalmic drops must not be injected.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Gatifloxacin ophthalmic solution 0.5% Sterile ophthalmic solution, 5 mg/mL. Not for injection. | Other | 5 mg / mL | TOPICAL |
| Zymar gatifloxacin ophthalmic drops 0.3% Sterile ophthalmic solution, separate from the existing 0.5% formulation. | Other | 3 mg / mL | TOPICAL |
Monitoring and Administration
Use a sterile eye preparation. Obtain cytology and culture for severe, progressive or melting ulcers.
Select application frequency from lesion severity and ophthalmic reassessment; do not transfer a human conjunctivitis schedule automatically to a veterinary corneal ulcer.
Use for established susceptible ocular bacterial infection rather than routine prophylaxis. Resistance patterns vary; a fluoroquinolone does not guarantee activity against Pseudomonas. Reassess clinical response and culture serious lesions.
Topical ophthalmic administration is distinct from systemic enrofloxacin exposure; feline retinal-toxicity thresholds for the latter are not adopted as eye-drop limits.