Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Trimethoprim is dosed at 15–30 mg/kg PO q12h in dogs, per Hillier A, Lloyd DH, Weese JS, et al. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (antimicrobial guidelines working group of the international society for companion animal infectious diseases). Vet Dermatol. 2014;25(3):163-e43. — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1222 (2026-08-01).. Trimethoprim is used in dogs for Susceptible infections (with sulfonamide). Routes documented in dogs: PO. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 1 cited dose rule for Trimethoprim in dogs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Tribrissen
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| PO | 15–30 mg/kg | q12h | 7-14 days | Susceptible infections (with sulfonamide) | Strong | Hillier A, Lloyd DH, Weese JS, et al. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (antimicrobial guidelines working group of the international society for companion animal infectious diseases). Vet Dermatol. 2014;25(3):163-e43. — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1222 (2026-08-01). |
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These ranges are per kg. Enter your dog's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Inhibits dihydrofolate reductase (DHFR) in folate synthesis pathway. Synergistic bactericidal activity when combined with sulfonamides.
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 dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Trimethoprim dose range in dogs, with cited source references: PO 15–30 mg/kg q12h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Trimethoprim in dogs: PO.
Cited course lengths for Trimethoprim in dogs include: 7-14 days. Duration depends on the indication — match it to the specific dose rule in the table above.
Trimethoprim is indicated in dogs for: Susceptible infections (with sulfonamide).
These are general warnings for Trimethoprim across species; consult the dog dosing table above for species-specific guidance. Almost always used in combination with a sulfonamide. Folate supplementation recommended in cats and during pregnancy. KCS risk in dogs.
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 dogs — 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.