Pocket Pet · Cavia porcellus · typical adult weight 0.70–1.20 kg
Trimethoprim-Sulfamethoxazole is dosed at 15–30 mg/kg PO q12h in guinea pigs, per Meredith A. BSAVA Small Animal Formulary: Part B: Exotic Pets, British Small Animal Veterinary Association, Quedgeley, Gloucester, UK; 2015.; Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.774 (2026-08-01).. Trimethoprim-Sulfamethoxazole is used in guinea pigs for Bacterial infections, Respiratory infections, Bacterial infections when oral not feasible. Routes documented in guinea pigs: PO, SC. A typical adult guinea pig weighs 0.70–1.20 kg. ExoticRx lists 3 cited dose rules for Trimethoprim-Sulfamethoxazole in guinea pigs, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Bactrim, TMS
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| PO | 15–30 mg/kg | q12h | 7-14 days | Bacterial infections | Moderate |
| Meredith A. BSAVA Small Animal Formulary: Part B: Exotic Pets, British Small Animal Veterinary Association, Quedgeley, Gloucester, UK; 2015.; Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.774 (2026-08-01). |
| PO | 15–30 mg/kg | q12h | 10-14 days | Respiratory infections | Moderate | Meredith A. BSAVA Small Animal Formulary: Part B: Exotic Pets, British Small Animal Veterinary Association, Quedgeley, Gloucester, UK; 2015. / 130. Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.774 (2026-08-01). |
| SC | 15–30 mg/kg | q12h | 7-14 days | Bacterial infections when oral not feasible | Moderate | Meredith A. BSAVA Small Animal Formulary: Part B: Exotic Pets, British Small Animal Veterinary Association, Quedgeley, Gloucester, UK; 2015. / 130. Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.774 (2026-08-01). |
Need the exact dose for your patient?
These ranges are per kg. Enter your guinea pig's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Sequential blockade of folate synthesis: sulfamethoxazole inhibits dihydropteroate synthase; trimethoprim inhibits dihydrofolate reductase.
May cause keratoconjunctivitis sicca (KCS) in dogs with prolonged use. Can cause bone marrow suppression. Avoid in animals with hepatic disease. Adequate hydration required.
Species-specific contraindications and adverse-reaction reports for guinea pigs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Trimethoprim-Sulfamethoxazole dose ranges in guinea pigs, with cited source references: PO 15–30 mg/kg q12h; PO 15–30 mg/kg q12h; SC 15–30 mg/kg q12h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Trimethoprim-Sulfamethoxazole in guinea pigs: PO, SC.
Cited course lengths for Trimethoprim-Sulfamethoxazole in guinea pigs include: 7-14 days; 10-14 days. Duration depends on the indication — match it to the specific dose rule in the table above.
Trimethoprim-Sulfamethoxazole is indicated in guinea pigs for: Bacterial infections, Respiratory infections, Bacterial infections when oral not feasible.
These are general warnings for Trimethoprim-Sulfamethoxazole across species; consult the guinea pig dosing table above for species-specific guidance. May cause keratoconjunctivitis sicca (KCS) in dogs with prolonged use. Can cause bone marrow suppression. Avoid in animals with hepatic disease. Adequate hydration required.
Why a species-specific page? Trimethoprim-Sulfamethoxazole pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in guinea pigs — 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.