Amoxicillin for Cattle

Livestock · Bos taurus · typical adult weight 250.00–900.00 kg

Amoxicillin is dosed at 6.6–11 mg/kg IM q24h in cattle, per 21 CFR 522.88(d)(2) (Amoxicillin), approved conditions of use for Cattle: 3 to 5 mg per pound of body weight daily for up to 5 days by intramuscular or subcutaneous injection (= 6.614-11.023 mg/kg; converted at 2.2046226 lb/kg). Indications as approved: respiratory tract infections (shipping fever, pneumonia) and acute necrotic pododermatitis (foot rot). Related tolerances: 21 CFR 556.38. Retrieved from the eCFR renderer API 2026-08-12. https://www.ecfr.gov/current/title-21/section-522.88. Amoxicillin is used in cattle for Respiratory infections, foot rot, Respiratory and GI infections. Routes documented in cattle: IM, PO. A typical adult cattle weighs 250.00–900.00 kg. ExoticRx lists 2 cited dose rules for Amoxicillin in cattle, drawn from published veterinary references. Verify against current literature before clinical use.

US trade names: Amoxi-Tabs, Amoxil

Contraindicated in Rabbit, Guinea Pig, Chinchilla, Hamster, Degu

Rabbit: Oral beta-lactams cause fatal dysbiosis in rabbitsOral amoxicillin (and other oral beta-lactams) selectively destroy gram-positive hindgut flora in rabbits, allowing Clostridium spiroforme overgrowth and fatal enterotoxemia. Never administer oral beta-lactams to rabbits. Parenteral administration carries a lower risk than the oral route, but is not established as safe in rabbits.
Guinea Pig: Oral beta-lactams cause fatal dysbiosis in guinea pigsOral amoxicillin reliably causes Clostridium difficile-mediated fatal enterotoxemia in guinea pigs. Same mechanism as in rabbits. Parenteral administration carries a lower risk than the oral route; parenteral ceftiofur specifically has been given to guinea pigs and chinchillas without adverse effect.
Chinchilla: Oral beta-lactams cause fatal dysbiosis in chinchillasChinchillas are hindgut fermenters with the same flora dependence as rabbits and guinea pigs. Oral penicillins and oral cephalosporins trigger Clostridium overgrowth and fatal enterotoxemia. Never give oral beta-lactams; parenteral routes and trimethoprim-sulfa, fluoroquinolones, or chloramphenicol are the safer choices.
Hamster: Oral beta-lactams cause fatal enterocolitis in hamstersHamsters are exquisitely susceptible to antibiotic-associated Clostridium difficile enterocolitis — the hamster is the classic laboratory model for it. Oral penicillins and cephalosporins are reliably fatal. Never administer oral beta-lactams.
Degu: Oral beta-lactams risk fatal dysbiosis in degusDegus are caviomorph hindgut fermenters closely related to chinchillas and guinea pigs. Degu-specific data is limited, so this warning is extrapolated from those related hystricomorphs — but the shared physiology makes oral beta-lactam enterotoxemia the expected outcome. Treat as contraindicated; use the safer alternatives.

Dose ranges

Route	Dose	Frequency	Duration	Indication	Evidence	Source
IM	6.6–11 mg/kg	q24h	3-5 days	Respiratory infections, foot rot	Moderate	21 CFR 522.88(d)(2) (Amoxicillin), approved conditions of use for Cattle: 3 to 5 mg per pound of body weight daily for up to 5 days by intramuscular or subcutaneous injection (= 6.614-11.023 mg/kg; converted at 2.2046226 lb/kg). Indications as approved: respiratory tract infections (shipping fever, pneumonia) and acute necrotic pododermatitis (foot rot). Related tolerances: 21 CFR 556.38. Retrieved from the eCFR renderer API 2026-08-12. https://www.ecfr.gov/current/title-21/section-522.88
PO	6.6–11 mg/kg	q12-24h	3-5 days	Respiratory and GI infections	Moderate	Verified against Papich/Saunders Handbook of Veterinary Drugs, 4th Ed, p.67 (2026-08-01). — 21 CFR § 522.88 (Amoxicillin), conditions of use for Cattle: 6.6139-11.0231 mg/kg (the regulation prints this per pound; converted at 2.2046226 lb/kg). Related tolerances: 21 CFR § 556.38. Retrieved from the eCFR API, snapshot 2026-01-01. — LOCATOR CONVENTION 2026-08-07: the bare 'p.67' in this citation is the PDF index of the held scan, not the printed page. The PRINTED page is p.39; verified by finding the drug named there. If you are holding the book, turn to p.39. — SOURCE EDITION: Saunders Handbook of Veterinary Drugs — ISBN 9780323244855,

What each reference text prints

Every held source for this drug and species, as printed. Where they differ, both are shown — the choice is yours, not ours.

Printed doses in mg/kg for this drug and species, by source
Dose (mg/kg)	Route	Source	As printed
10–22	PO	Papich Saunders Handbook of Veterinary Drugs, 4th edp.67	• Nonruminating: 10-22 mg/kg q8-12h PO.
6.6–22	PO	Papich Saunders Handbook of Veterinary Drugs, 4th edp.67	• 6.6-22 mg/kg q8-12h PO (suspension). Note: Oral doses in large animals are not

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.

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Mechanism of action

Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs).

Side effects & warnings

CONTRAINDICATED in rabbits, guinea pigs, and hamsters (fatal dysbiosis). May cause GI upset. Cross-reactivity with other beta-lactams.

Species-specific contraindications and adverse-reaction reports for cattle may differ from canine / feline reference data — consult the primary citations listed with each rule.

Frequently asked questions

What is the dose of Amoxicillin for Cattle?

Amoxicillin dose ranges in cattle, with cited source references: IM 6.6–11 mg/kg q24h; PO 6.6–11 mg/kg q12-24h. Reference ranges from cited sources — verify against current literature before clinical use.

How is Amoxicillin administered in Cattle?

Documented routes for Amoxicillin in cattle: IM, PO.

How long is Amoxicillin given in Cattle?

Cited course lengths for Amoxicillin in cattle include: 3-5 days. Duration depends on the indication — match it to the specific dose rule in the table above.

What conditions does Amoxicillin treat in Cattle?

Amoxicillin is indicated in cattle for: Respiratory infections, foot rot, Respiratory and GI infections.

What are the side effects of Amoxicillin in Cattle?

These are general warnings for Amoxicillin 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.

Other Antibiotic drugs with cattle dosing

Ampicillin Bacitracin (Livestock Feed)Bambermycin Cefquinome (Livestock)Ceftiofur Ceftiofur Crystalline Free Acid (Long-Acting)Cephapirin (Intramammary Dry Cow)Danofloxacin (Livestock)Doxycycline Erythromycin Florfenicol Gamithromycin

Amoxicillin dosing in other species

Chickens Swine Turkeys African Grey Parrots African Pygmy Hedgehogs Ball Pythons Bearded Dragons Bettas

See all species for Amoxicillin See all drugs for Cattle

Why a species-specific page? Amoxicillin 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.