Which species have cited Trimethoprim dosing data?

Trimethoprim dosing in the ExoticRx formulary covers 7 species: African Grey Parrot, Ball Python, Cat (Domestic), Dog (Domestic), Domestic Pigeon, Rabbit (Domestic), Zebra Finch.

Is Trimethoprim a controlled substance?

Trimethoprim is not federally scheduled in the US. Controlled-drug status differs by country — verify your local rules.

Trimethoprim

US brand names:Tribrissen(with sulfadiazine)

Calculate dosage

Sourced from published veterinary references. Awaiting credentialed clinical reviewer — our editorial process.

Trimethoprim is dosed at 15–25 mg/kg PO q24-48h in ball pythons, per Mader's Table 127.1, corpus p.1404 (printed 1194); Plumb's Sulfa-/Trimethoprim REPTILES, corpus p.1223, incl. 'may consider giving dose every other day after the second dose' — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207; Mader's Reptile and Amphibian Medicine and Surgery (Divers & Stahl) — ISBN 9780323482530, https://openlibrary.org/isbn/9780323482530. Verify against current literature before clinical use.

Drug Class

Antibiotic

Routes

POIV

Indications

Bacterial infectionsBacteriostatic gram-positive and gram-negative coverRespiratory/urinary infectionsSusceptible infections (TMP-sulfa)Susceptible infections (with sulfonamide)

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 with Trimethoprim dosing data (7 dose rules)

African Grey Parrot Ball Python Cat (Domestic)Dog (Domestic)Domestic Pigeon Rabbit (Domestic)Zebra Finch

Species references:All African Grey Parrot drugs All Ball Python drugs All Cat (Domestic) drugs All Dog (Domestic) drugs All Domestic Pigeon drugs All Rabbit (Domestic) drugs All Zebra Finch drugs

Evidence levels across 7 dose rules

Weak×1Moderate×4Strong×2

Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.

Backed by 7 published sources

· 236. Dorrestein GM. Studies on Pharmacokinetics of Some Antibacterial Agents in Homing Pigeons (Columba livia), Thesis: Utrecht University; 1986. | 240. Dorrestein GM. Antimicrobial drug use in companion birds. In: PrescottJF, Baggot JD, Walker RD, eds. Antimicrobial Therapy in Veterinary Medicine, 3rd ed., Iowa State University Press, Ames, IA; 2000:617-636. | 585. Marx KL, Roston MA. The Exotic Animal Drug Compendium: An International Formulary, Veterinary Learning Systems, Trenton, NJ; 1996. — Source: Carpenter's Exotic Animal Formulary, 6th Ed, p.422 [DOI REMOVED w3r2 2026-08-14 - resolved at Crossref on 2026-08-14 to Flammer K, Antimicrobial Drug Use in Companion Birds, Wiley, published 2013, pages 589-600, i.e. the same-titled chapter in the FIFTH edition by a DIFFERENT author. The citation names Dorrestein GM, 3rd ed, Iowa State University Press, 2000:617-636. Author, edition, publisher, year and page range all differ, so the link opened a document that is not the cited source. Whether the 5th ed chapter carries the same figure is UNCHECKED] — Carpenter's Exotic Animal Formulary 6th ed, Table 5.1 (Antimicrobial Agents Used in Birds.a). The copy held is an ebook conversion with no printed page numbers, so the table — not the page — is the citable location. — SOURCE EDITION: Carpenter's Exotic Animal Formulary — ISBN 9780323833929, https://openlibrary.org/isbn/9780323833929

Sample dosing (2 of 7 cited rules)

A dog/cat sample is shown here. Cited dosing for all 7 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.

Species	Route	Dose	Frequency	Evidence	Source
Dog (Domestic)	PO	15–30 mg/kg	q12h	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). — LOCATOR CONVENTION 2026-08-07: the bare 'p.1222' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.1195; verified by finding the drug named there. If you are holding the book, turn to p.1195. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207
Cat (Domestic)	PO	15–30 mg/kg	q12h	Strong

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Calculate Dosage for Trimethoprim

· 236. Dorrestein GM. Studies on Pharmacokinetics of Some Antibacterial Agents in Homing Pigeons (Columba livia), Thesis: Utrecht University; 1986. — Source: Carpenter's Exotic Animal Formulary, 6th Ed, p.422 — Carpenter's Exotic Animal Formulary 6th ed, Table 5.1 (Antimicrobial Agents Used in Birds.a). The copy held is an ebook conversion with no printed page numbers, so the table — not the page — is the citable location. — SOURCE EDITION: Carpenter's Exotic Animal Formulary — ISBN 9780323833929, https://openlibrary.org/isbn/9780323833929

· Flammer K. Treatment of bacterial and mycotic diseases of the avian gastrointestinal tract. Proc North Am Vet Conf; 2002:851-852. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.422 (2026-08-01). — Carpenter's Exotic Animal Formulary 6th ed, Table 5.1 (Antimicrobial Agents Used in Birds.a). The copy held is an ebook conversion with no printed page numbers, so the table — not the page — is the citable location. — SOURCE EDITION: Carpenter's Exotic Animal Formulary — ISBN 9780323833929, https://openlibrary.org/isbn/9780323833929

· 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). — LOCATOR CONVENTION 2026-08-07: the bare 'p.1222' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.1195; verified by finding the drug named there. If you are holding the book, turn to p.1195. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207

· Mader's Table 127.1, corpus p.1404 (printed 1194); Plumb's Sulfa-/Trimethoprim REPTILES, corpus p.1223, incl. 'may consider giving dose every other day after the second dose' — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207; Mader's Reptile and Amphibian Medicine and Surgery (Divers & Stahl) — ISBN 9780323482530, https://openlibrary.org/isbn/9780323482530

· Plumb DC. Plumb’s Veterinary Drug Handbook, 9th — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.845 (2026-08-01). — Carpenter's Exotic Animal Formulary 6th ed, Table 10.1 (Antimicrobial Agents Used in Rabbits.a). The copy held is an ebook conversion with no printed page numbers, so the table — not the page — is the citable location. — EDITION NOTE 2026-08-06: this rule's Plumb's reference names the 9th edition, which is not held and was never consulted. The held copy is the 10th ed (2023). The Plumb's line was never confirmed against the held edition, so rely on it only as background; any other source named in this citation is unaffected. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207; Carpenter's Exotic Animal Formulary — ISBN 9780323833929, https://openlibrary.org/isbn/9780323833929

· Weese JS, Blondeau J, Boothe D, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019;247:8-25. doi:10.1016/j.tvjl.2019.02.008 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1223 (2026-08-01). — LOCATOR CONVENTION 2026-08-07: the bare 'p.1223' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.1196; verified by finding the drug named there. If you are holding the book, turn to p.1196. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207

Weese JS, Blondeau J, Boothe D, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019;247:8-25. doi:10.1016/j.tvjl.2019.02.008 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1223 (2026-08-01). — LOCATOR CONVENTION 2026-08-07: the bare 'p.1223' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.1196; verified by finding the drug named there. If you are holding the book, turn to p.1196. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207