Livestock · Bos taurus · typical adult weight 250.00–900.00 kg
Ampicillin is dosed at 4.4–11 mg/kg IM q24h; do not treat for more than 7 days in cattle, per Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted) — Ampicillin, Dosages, CATTLE, Polyflex label dosage, printed p. 80 (corpus PDF p. 107); corroborated by Papich Handbook of Veterinary Drugs, 5th Ed, 'Cattle and Calves — Ampicillin Trihydrate: 4.4 to 11 mg/kg q24h IM', printed p. 45 (corpus PDF p. 73) — 21 CFR § 522.90b (Ampicillin trihydrate powder for injection), conditions of use for Cattle: 4.4092-11.0231 mg/kg (the regulation prints this per pound; converted at 2.2046226 lb/kg). Related tolerances: 21 CFR § 556.40. Retrieved from the eCFR API, snapshot 2026-01-01. https://www.ecfr.gov/current/title-21/section-522.90b — EDITION UNVERIFIABLE 2026-08-07: this citation names Papich 5th ed, which is NOT held. Its page locator does not resolve to a page naming this drug in the held 4th ed (2016), so the reference cannot be confirmed against any copy available here. Treat the page number as unchecked and consult the 5th edition directly. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207; Saunders Handbook of Veterinary Drugs — ISBN 9780323244855, https://openlibrary.org/isbn/9780323244855. Ampicillin is used in cattle for Respiratory tract infections (bacterial pneumonia: shipping fever, calf pneumonia, bovine pneumonia). Routes documented in cattle: IM. A typical adult cattle weighs 250.00–900.00 kg. ExoticRx lists 1 cited dose rule for Ampicillin in cattle, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Polyflex
Contraindicated in Rabbit, Guinea Pig, Chinchilla, Hamster, Degu
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| IM | 4.4–11 mg/kg | q24h; do not treat for more than 7 days | 3-5 days | Respiratory tract infections (bacterial pneumonia: shipping fever, calf pneumonia, bovine pneumonia) | Moderate | Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted) — Ampicillin, Dosages, CATTLE, Polyflex label dosage, printed p. 80 (corpus PDF p. 107); corroborated by Papich Handbook of Veterinary Drugs, 5th Ed, 'Cattle and Calves — Ampicillin Trihydrate: 4.4 to 11 mg/kg q24h IM', printed p. 45 (corpus PDF p. 73) — 21 CFR § 522.90b (Ampicillin trihydrate powder for injection), conditions of use for Cattle: 4.4092-11.0231 mg/kg (the regulation prints this per pound; converted at 2.2046226 lb/kg). Related tolerances: 21 CFR § 556.40. Retrieved from the eCFR API, snapshot 2026-01-01. https://www.ecfr.gov/current/title-21/section-522.90b — EDITION UNVERIFIABLE 2026-08-07: this citation names Papich 5th ed, which is NOT held. Its page locator does not resolve to a page naming this drug in the held 4th ed (2016), so the reference cannot be confirmed against any copy available here. Treat the page number as unchecked and consult the 5th edition directly. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207; Saunders Handbook of Veterinary Drugs — ISBN 9780323244855, https://openlibrary.org/isbn/9780323244855 |
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Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins. Broader spectrum than penicillin G with gram-negative coverage.
CONTRAINDICATED in rabbits, guinea pigs, and hamsters (fatal dysbiosis). May cause GI upset. Cross-reactivity with other beta-lactams. IM injection may be painful.
Species-specific contraindications and adverse-reaction reports for cattle may differ from canine / feline reference data — consult the primary citations listed with each rule.
Ampicillin dose range in cattle, with cited source references: IM 4.4–11 mg/kg q24h; do not treat for more than 7 days. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Ampicillin in cattle: IM.
Cited course lengths for Ampicillin in cattle include: 3-5 days. Duration depends on the indication — match it to the specific dose rule in the table above.
Ampicillin is indicated in cattle for: Respiratory tract infections (bacterial pneumonia: shipping fever, calf pneumonia, bovine pneumonia).
These are general warnings for Ampicillin across species; consult the cattle dosing table above for species-specific guidance. CONTRAINDICATED in rabbits, guinea pigs, and hamsters (fatal dysbiosis). May cause GI upset. Cross-reactivity with other beta-lactams. IM injection may be painful.
Why a species-specific page? Ampicillin pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in cattle — 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.