Dog · Canis lupus familiaris · typical adult weight 2.00–80.00 kg
Ampicillin is dosed at 20–40 mg/kg IV q6-8h in dogs, per MacDonald K. Infective endocarditis in dogs: diagnosis and therapy. Vet Clin North Am Small Anim Pract. 2010;40:665-684. doi:10.1016/j.cvsm.2010.03.010 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.107 (2026-08-01). — Plumb's 10th ed (held) printed p.78, Ampicillin monograph spanning p.78-81; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Ampicillin is used in dogs for Surgical prophylaxis, bacteremia, Susceptible bacterial infections. Routes documented in dogs: IV, PO. A typical adult dog weighs 2.00–80.00 kg. ExoticRx lists 2 cited dose rules for Ampicillin in dogs, 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 |
|---|---|---|---|---|---|---|
| IV | 20–40 mg/kg | q6-8h | Peri-operative or 7-14 days | Surgical prophylaxis, bacteremia | Strong | MacDonald K. Infective endocarditis in dogs: diagnosis and therapy. Vet Clin North Am Small Anim Pract. 2010;40:665-684. doi:10.1016/j.cvsm.2010.03.010 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.107 (2026-08-01). — Plumb's 10th ed (held) printed p.78, Ampicillin monograph spanning p.78-81; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |
| PO | 10–20 mg/kg | q6-8h | 7-14 days | Susceptible bacterial infections | Strong | Plumb's Veterinary Drug Handbook, 10th ed (2023, held copy; the original seed cited the 9th, which was never consulted) — Plumb's 10th ed (held) printed p.78, Ampicillin monograph spanning p.78-81; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — figure located 2026-08-05 at Plumb's 10th ed printed p.79, Ampicillin monograph; the page cited previously does not carry it. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, |
Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.
The sources disagree for this combination. The ranges below do not overlap on a comparable route. This is not an error in one of them — published veterinary references differ, and reconciling them for a particular patient is a clinical judgement.
| Dose (mg/kg) | Route | Source | As printed |
|---|---|---|---|
| 10–20 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.44 | 10-20 mg/kg i.v., i.m., s.c., p.o. q6-8h. |
| 40 | IV | BSAVA Small Animal Formulary, 10th ed — Part A (Canine and Feline)p.44 | up to 40 mg/kg i.v. q6h has been recommended |
| 10–20 | IV | Papich Saunders Handbook of Veterinary Drugs, 4th edp.73 | • 10-20 mg/kg q6-8h IV, IM, or SQ or 20-40 mg/kg q8h PO. Doses as high as |
| 20–40 |
Need the exact dose for your patient?
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 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 dogs may differ from canine / feline reference data — consult the primary citations listed with each rule.
Ampicillin dose ranges in dogs, with cited source references: IV 20–40 mg/kg q6-8h; PO 10–20 mg/kg q6-8h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Ampicillin in dogs: IV, PO.
Cited course lengths for Ampicillin in dogs include: Peri-operative or 7-14 days; 7-14 days. Duration depends on the indication — match it to the specific dose rule in the table above.
Ampicillin is indicated in dogs for: Surgical prophylaxis, bacteremia, Susceptible bacterial infections.
These are general warnings for Ampicillin across species; consult the dog 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 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.
| IV |
| Papich Saunders Handbook of Veterinary Drugs, 4th edp.73 |
| • 10-20 mg/kg q6-8h IV, IM, or SQ or 20-40 mg/kg q8h PO. Doses as high as |
| 100 | — | Papich Saunders Handbook of Veterinary Drugs, 4th edp.73 | 100 mg/kg have been used for some resistant infections such as those caused by |
| 10–50 | IM | Papich Saunders Handbook of Veterinary Drugs, 4th edp.73 | • 10-50 mg/kg q12-24h IM or SQ. |
Figures are transcribed from the cited page or table of each held edition and are shown for reference only. They are not dose recommendations, they do not feed the calculator, and none has been reviewed by a veterinarian.