Trimethoprim for Cat
Cat · Felis catus · typical adult weight 2.50–7.00 kg
Trimethoprim is used in cat for Susceptible infections (with sulfonamide). Routes documented in cat: PO. A typical adult cat weighs 2.50–7.00 kg. ExoticRx lists 1 cited dose rule for Trimethoprim in cat, drawn from published veterinary references. Verify against current literature before clinical use.
Trade names: Tribrissen
Dose ranges
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| PO | 15–30 mg/kg | q12h | 7-14 days | Susceptible infections (with sulfonamide) | Strong | Plumb's Veterinary Drug Handbook, 9th Ed |
Need the exact dose for your patient?
These ranges are per kg. Enter your cat's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Mechanism of action
Inhibits dihydrofolate reductase (DHFR) in folate synthesis pathway. Synergistic bactericidal activity when combined with sulfonamides.
Side effects & warnings
Almost always used in combination with a sulfonamide. Folate supplementation recommended in cats and during pregnancy. KCS risk in dogs.
Species-specific contraindications and adverse-reaction reports for cat may differ from canine / feline reference data — consult the primary citations listed with each rule.
Other Antibiotic drugs with cat dosing
Trimethoprim dosing in other species
Why a species-specific page? Trimethoprim pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in cat — the rules above are the citations specific to this species, not generic recommendations.
Sourced from published veterinary references; awaiting credentialed clinical reviewer. See our editorial process. Reference only — not veterinary advice.