Cephalexin for Syrian Hamsters

Pocket Pet · Mesocricetus auratus · typical adult weight 0.09–0.14 kg

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.

Contraindicated in syrian hamsters: Oral beta-lactams cause fatal enterocolitis in hamsters. Cephalexin is dosed at 25 mg/kg SC q24h in syrian hamsters, per Carpenter's Exotic Animal Formulary, 6th ed, Table 9.1 (Antimicrobial and Antifungal Agents Used in Rodents): 'Cephalexin 25 mg/kg SC q24h130 | Hamsters, gerbils'. NOTE: the previously named primary (Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents, 4th ed., 2021:620-630) prints q12h, NOT q24h, for this species and route, and does not support the served frequency. The two held books disagree on the interval and the frequency field is deliberately NOT changed. Cephalexin is used in syrian hamsters for Antimicrobial (general). Routes documented in syrian hamsters: SC. A typical adult syrian hamster weighs 0.09–0.14 kg. ExoticRx lists 1 cited dose rule for Cephalexin in syrian hamsters, drawn from published veterinary references. Verify against current literature before clinical use.

Dose ranges

Route	Dose	Frequency	Indication	Evidence	Source
SC	25 mg/kg	q24h	Antimicrobial (general)	Weak	Carpenter's Exotic Animal Formulary, 6th ed, Table 9.1 (Antimicrobial and Antifungal Agents Used in Rodents): 'Cephalexin 25 mg/kg SC q24h130 \| Hamsters, gerbils'. NOTE: the previously named primary (Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents, 4th ed., 2021:620-630) prints q12h, NOT q24h, for this species and route, and does not support the served frequency. The two held books disagree on the interval and the frequency field is deliberately NOT changed.Compilation only — we have not located an independent source that prints this figure.

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
25	SC	Carpenter's Exotic Animal Formulary, 6th edTable 9.1	25 mg/kg SC q24h

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.

Calculate the dose for your syrian hamster

3 a day (1 exotic) · no account needed

Drug

Cephalexin (Keflex)

Weight

Typical range: 85–140 g

Route

Concentration (optional, mg/ml)

If provided, volume will be calculated alongside dose.

Reference only. Verify against current literature before clinical use.

Side effects & warnings

May cause GI upset. Use with caution in penicillin-allergic animals (cross-reactivity). Not effective against Pseudomonas.

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

Frequently asked questions

What is the dose of Cephalexin for Syrian Hamsters?

Contraindicated in syrian hamsters: Oral beta-lactams cause fatal enterocolitis in hamsters. Cephalexin dose range in syrian hamsters, with cited source references: SC 25 mg/kg q24h. Reference ranges from cited sources — verify against current literature before clinical use.

How is Cephalexin administered in Syrian Hamsters?

Contraindicated in syrian hamsters: Oral beta-lactams cause fatal enterocolitis in hamsters. Documented routes for Cephalexin in syrian hamsters: SC.

What conditions does Cephalexin treat in Syrian Hamsters?

Contraindicated in syrian hamsters: Oral beta-lactams cause fatal enterocolitis in hamsters. Cephalexin is indicated in syrian hamsters for: Antimicrobial (general).

What are the side effects of Cephalexin in Syrian Hamsters?

Contraindicated in syrian hamsters: Oral beta-lactams cause fatal enterocolitis in hamsters. These are general warnings for Cephalexin across species; consult the syrian hamster dosing table above for species-specific guidance. May cause GI upset. Use with caution in penicillin-allergic animals (cross-reactivity). Not effective against Pseudomonas.

Why a species-specific page? Cephalexin pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in syrian hamsters — the rules above are the citations specific to this species, not generic recommendations.