# Ceftriaxone: veterinary dose and monograph > Ceftriaxone is a veterinary antibiotic. 3rd-generation cephalosporin, broad-spectrum bactericidal. Indications include severe systemic / Gram-negative bacterial infections; haemorrhagic septicaemia, pneumonia, bronchopneumonia; mastitis, metritis, pyometra, endometritis. This monograph lists 5 reference doses for dogs, cats, cattle, horses and primates, each with route, frequency and source, plus meat and milk withdrawal periods for food animals. Source: https://vetmasterji.com/drugs/ceftriaxone · Last reviewed: 2026-10-01 ## At a glance - **Drug class:** Antibiotic - **Also known as:** Intacef, Intacef Tazo, Rocephin - **Species with doses:** Dogs, Cats, Cattle, Horses and Primates - **General dose range:** 5–25 mg/kg IV q24h — check the species tables for the indication - **Routes:** IM, IV - **Last reviewed:** 1 October 2026 ## Indications - Severe systemic / Gram-negative bacterial infections - Haemorrhagic septicaemia, pneumonia, bronchopneumonia - Mastitis, metritis, pyometra, endometritis - Actinobacillosis, osteoarthritis - Peri-operative prophylaxis ## Ceftriaxone dose by species Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them. ### Dogs *Ceftriaxone doses for dogs* | Indication | Dose | Route | Frequency | Duration | | --- | --- | --- | --- | --- | | Severe sepsis / pyometra / CNS infection | 15–25 mg/kg | IV | q12–24h | 5–7 days | - Severe sepsis / pyometra / CNS infection: Plumb’s p.237 (Greene & Watson 1998): meningitis/borreliosis 15–50 mg/kg IV or IM q12h for 4–14 days; skin/genitourinary 25 mg/kg IM q24h for 7–14 days; peri-operative 25 mg/kg once; endocarditis 20 mg/kg IV q12h (DeFrancesco 2000). Give IV slowly over 2–4 min. ### Cats *Ceftriaxone doses for cats* | Indication | Dose | Route | Frequency | Duration | | --- | --- | --- | --- | --- | | Systemic infection | 25–50 mg/kg | IV | q12h | as long as necessary | - Systemic infection: Plumb’s p.237 (Greene & Watson 1998): cats 25–50 mg/kg IV, IM or intraosseously q12h for systemic infections. ### Cattle *Ceftriaxone doses for cattle* | Indication | Dose | Route | Frequency | Duration | Withdrawal | | --- | --- | --- | --- | --- | --- | | Mastitis / HS / metritis / pneumonia | 5–10 mg/kg | IM | q24h | 3–5 days | Withdrawal NOT established — treat as extra-label | - Mastitis / HS / metritis / pneumonia: IV or deep IM. WITHDRAWAL NOT ESTABLISHED: ceftriaxone is a human-label cephalosporin with no food-animal approval, and Plumb's carries no meat or milk withdrawal for it (the withdrawal figures on the neighbouring page belong to CEFTIOFUR, which is the food-animal cephalosporin). Indian catalogues nevertheless sell ceftriaxone widely for cattle and state no withdrawal. Treat every use in a food animal as extra-label with an undetermined withdrawal — contact FARAD, or use ceftiofur where a labelled withdrawal exists. No cattle dose appears in Papich 5e or Plumb’s; this regimen follows Indian veterinary product literature (Intacef). Dose source: Indian product labelling (5–10 mg/kg IM or IV once daily for 3–5 days) — neither Papich 5e nor Plumb’s gives a cattle ceftiofur-alternative dose for ceftriaxone. Prefer a cephalosporin licensed for cattle (ceftiofur, cefquinome). ### Horses *Ceftriaxone doses for horses* | Indication | Dose | Route | Frequency | Duration | | --- | --- | --- | --- | --- | | Susceptible infection (extra-label) | 25–50 mg/kg | IV | q12h | — | - Susceptible infection (extra-label): Plumb’s p.237: 25–50 mg/kg IV or IM q12h — excellent CSF and bone penetration (Stewart 2008); 20 mg/kg IV q12h (Brumbaugh 1999). ### Goats *Ceftriaxone doses for goats* | Indication | Dose | Route | Frequency | Duration | Withdrawal | | --- | --- | --- | --- | --- | --- | | No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — | - No reference dose for this species: The previous 10–15 mg/kg IM goat row had no source; neither Papich 5e nor Plumb’s gives a small-ruminant ceftriaxone dose, and no food-animal withdrawal exists. ### Sheep *Ceftriaxone doses for sheep* | Indication | Dose | Route | Frequency | Duration | Withdrawal | | --- | --- | --- | --- | --- | --- | | No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — | - No reference dose for this species: The previous 10–15 mg/kg IM sheep row had no source; neither Papich 5e nor Plumb’s gives a small-ruminant ceftriaxone dose, and no food-animal withdrawal exists. ### Buffalo No buffalo-specific doses are on file, so buffalo are dosed as cattle. *Ceftriaxone doses for buffalo* | Indication | Dose | Route | Frequency | Duration | Withdrawal | | --- | --- | --- | --- | --- | --- | | Mastitis / HS / metritis / pneumonia | 5–10 mg/kg | IM | q24h | 3–5 days | Withdrawal NOT established — treat as extra-label | - Mastitis / HS / metritis / pneumonia: IV or deep IM. WITHDRAWAL NOT ESTABLISHED: ceftriaxone is a human-label cephalosporin with no food-animal approval, and Plumb's carries no meat or milk withdrawal for it (the withdrawal figures on the neighbouring page belong to CEFTIOFUR, which is the food-animal cephalosporin). Indian catalogues nevertheless sell ceftriaxone widely for cattle and state no withdrawal. Treat every use in a food animal as extra-label with an undetermined withdrawal — contact FARAD, or use ceftiofur where a labelled withdrawal exists. No cattle dose appears in Papich 5e or Plumb’s; this regimen follows Indian veterinary product literature (Intacef). Dose source: Indian product labelling (5–10 mg/kg IM or IV once daily for 3–5 days) — neither Papich 5e nor Plumb’s gives a cattle ceftiofur-alternative dose for ceftriaxone. Prefer a cephalosporin licensed for cattle (ceftiofur, cefquinome). ### Primates *Ceftriaxone doses for primates* | Indication | Dose | Route | Frequency | Duration | | --- | --- | --- | --- | --- | | Susceptible infection (monkeys, siamangs) | 25–100 mg/kg | IM | q12h | — | - Susceptible infection (monkeys, siamangs): Carpenter Exotic Animal Formulary 6th ed, Table 13-1 (p.681): monkeys/siamangs 25–100 mg/kg IM or IV q12h; chimpanzees 50–100 mg/kg IM q12–24h. ## Contraindications Cephalosporin hypersensitivity (cross-reactivity with penicillins). Use cautiously in renal failure (reduce dose). Do NOT mix with calcium-containing IV solutions — precipitate / fatal lung & kidney emboli. Not approved for food animals in many jurisdictions — confirm withdrawal locally. ## Species-specific warnings > **Caution:** Rabbits: Avoid in rabbits — cephalosporins can cause fatal clostridial enterotoxaemia. ## Adverse effects - GI upset (vomiting, diarrhoea) - Local injection-site pain (IM) - Hypersensitivity / urticaria (rare) - Biliary pseudolithiasis (high doses, dogs) - Calcium-ceftriaxone precipitation in IV lines ## Drug interactions - Aminoglycosides (gentamicin): synergistic against many Gram-negatives — but do NOT mix in same syringe (physical inactivation) - Loop diuretics (furosemide) / nephrotoxins: additive nephrotoxicity in dehydrated patients - Calcium-containing IV solutions: NEVER co-infuse with ceftriaxone in same line — precipitation can cause fatal embolism (esp. in neonates) - Penicillins: cross-reactivity for hypersensitivity (~10% co-allergy) - Warfarin / oral anticoagulants: may potentiate anticoagulation - Probenecid: prolongs ceftriaxone half-life ## Pregnancy and lactation Generally considered safe in pregnancy at therapeutic doses. Crosses placenta in low concentrations. Excreted in milk. FDA Category B (human). Used in pregnant queens, bitches, mares for severe infections. ## Monitoring - Renal function (BUN, creatinine) baseline and on prolonged courses - CBC if treatment exceeds 7 days — rare neutropenia / thrombocytopenia - Hypersensitivity signs especially first dose - Injection-site for pain / swelling (deep IM technique) - Withdrawal periods (cattle extra-label): cross-reference with FARAD - NEVER mix with Ca²⁺-containing IV solutions (LRS, calcium gluconate) ## Toxicity and overdose Wide therapeutic margin. Acute toxicity rare. Chronic high-dose: granulocytopenia, thrombocytopenia (reversible). Biliary sludge / pseudolithiasis with prolonged high-dose use (calcium chelation in bile). Hypersensitivity (urticaria, anaphylaxis). NEONATES: NEVER co-administer with calcium-containing solutions — fatal calcium-ceftriaxone precipitate in lungs / kidneys. Management: No specific antidote. Supportive: IV fluids, anti-emetic. Anaphylaxis: epinephrine 0.01 mg/kg IM, diphenhydramine, corticosteroid. Hemodialysis NOT effective (highly protein-bound). Biliary sludge: usually self-resolves on discontinuation. ## Clinical pearls - Canine severe sepsis / CNS infection: 15–25 mg/kg IV slow over 2–4 min q12–24h - Canine pyometra (pre-/post-op coverage): 25 mg/kg IV q12h - Bovine respiratory disease, mastitis, metritis: 5–10 mg/kg IM q24h × 3–5 days — Intacef widely used in Indian dairy - Goats / sheep: 10–15 mg/kg IM q24h × 3–5 days - Equine: 25–50 mg/kg IV q12–24h for severe Gram-negative sepsis (extra-label, foals especially) - Intacef Tazo (with tazobactam) extends spectrum to ESBL-producing organisms — useful for refractory UTI / sepsis - NEVER co-infuse with calcium-containing fluids (LRS) — fatal precipitate in lungs/kidneys, especially in neonates - Reconstituted solution stable 24 h at RT — convenient for once-daily clinic use ## Mechanism of action Third-generation cephalosporin (human-medicine origin, extra-label in vet practice). Binds penicillin-binding proteins (PBPs) — inhibits transpeptidase cross-linking of peptidoglycan. Bactericidal, time-dependent killing. Extended-spectrum: enhanced Gram-negative coverage (E. coli, Klebsiella, Proteus, Enterobacter, Pasteurella), weaker on Gram-positives than 1st-gen. Stable to most beta-lactamases (further stabilised by tazobactam combination — Intacef Tazo). Excellent CSF penetration in inflamed meninges. Long half-life (~6 h) allows q24h dosing in most species. ## Formulations and products - Intacef dry-powder vials 250 mg / 500 mg / 1 g / 2 g / 3 g / 4 g / 5 g (Intas) — reconstitute per label - Intacef Tazo dry-powder vials 562.5 mg / 2.25 g / 3.375 g / 4.5 g / 5.625 g (Intas) — reconstitute per label - Powder reconstituted to ≈100 mg/mL (Plumb’s p.237 — diluent volume per vial label) - Powder reconstituted to 250 mg/mL (Plumb’s p.237 — diluent volume per vial label) - Intacef (Intas (Neovet)) — 250 mg, Vial + WFI + sterile syringe - Intacef (Intas (Neovet)) — 500 mg, Vial + WFI - Intacef (Intas (Neovet)) — 1 g, Vial + WFI - Intacef (Intas (Neovet)) — 2 g, Vial + WFI - Intacef (Intas (Neovet)) — 3 g / 4 g / 5 g, Vial + WFI (large animal pack) - Intacef Tazo (Intas (Neovet)) — Ceftriaxone 500 + Tazobactam 62.5 mg, Vial + WFI - Intacef Tazo (Intas (Neovet)) — Ceftriaxone 4 g + Tazobactam 500 mg, Large-animal vial - Ceftiforce-500 (Pet Mankind (Mankind Pharma)) — Ceftriaxone 500 mg, Vial - Ceftiforce-Tazo (Pet Mankind (Mankind Pharma)) — Ceftriaxone 500 + Tazobactam 62.5 mg, Vial - Seftravet-3 (Assure Biotech, Jagadhri (HR)) — 3 g ceftriaxone, Dry powder vial + 20 mL WFI ampoule - Monocef — 250 / 500 / 1000 / 2000 mg, Vial (human-label) - Rocephin — 250 / 500 / 1000 / 2000 mg, Vial (human-label) ## Storage Powder vials: 15–25 °C, protected from light. Reconstituted solution: use within 24 h at room temp or 48 h refrigerated. Multidose vial: discard 28 days after broaching. Tazobactam combination (Intacef Tazo): same conditions. ## Before you use this dose > **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision. ## Other antibiotics - [Cefpodoxime proxetil](https://vetmasterji.com/drugs/cefpodoxime) - [Cefquinome](https://vetmasterji.com/drugs/cefquinome) - [Ceftazidime](https://vetmasterji.com/drugs/ceftazidime) - [Ceftiofur](https://vetmasterji.com/drugs/ceftiofur) - [Cefuroxime](https://vetmasterji.com/drugs/cefuroxime) - [Cephalexin](https://vetmasterji.com/drugs/cephalexin) - [Chloramphenicol](https://vetmasterji.com/drugs/chloramphenicol) - [Ciprofloxacin](https://vetmasterji.com/drugs/ciprofloxacin) ## Frequently asked questions ### What is the dose of Ceftriaxone for dogs? Reference doses for Ceftriaxone in dogs: 15–25 mg/kg IV q12–24h for 5–7 days (Severe sepsis / pyometra / CNS infection). Confirm against the label and the patient before use. ### What is the dose of Ceftriaxone for cats? Reference doses for Ceftriaxone in cats: 25–50 mg/kg IV q12h for as long as necessary (Systemic infection). Confirm against the label and the patient before use. ### What is the dose of Ceftriaxone for cattle? Reference doses for Ceftriaxone in cattle: 5–10 mg/kg IM q24h for 3–5 days (Mastitis / HS / metritis / pneumonia). Confirm against the label and the patient before use. ### What is the withdrawal period for Ceftriaxone? Cattle, IM (Mastitis / HS / metritis / pneumonia): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ. ### When should Ceftriaxone not be used? Cephalosporin hypersensitivity (cross-reactivity with penicillins). Use cautiously in renal failure (reduce dose). Do NOT mix with calcium-containing IV solutions — precipitate / fatal lung & kidney emboli. Not approved for food animals in many jurisdictions — confirm withdrawal locally. ### What are the side effects of Ceftriaxone in animals? GI upset (vomiting, diarrhoea); Local injection-site pain (IM); Hypersensitivity / urticaria (rare); Biliary pseudolithiasis (high doses, dogs); Calcium-ceftriaxone precipitation in IV lines. ## Sources - Intas Animal Health catalogue · Intacef / Intacef Tazo - Plumb's Veterinary Drug Handbook - Papich, Papich Handbook of Veterinary Drugs, 5th edition - Carpenter, Exotic Animal Formulary --- VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.