Carbenicillin for Russian Tortoises

Reptile · Testudo horsfieldii · typical adult weight 0.23–0.91 kg

Carbenicillin is dosed at 200–400 mg/kg IM q 24 h in russian tortoises, per Merck Veterinary Manual. Antimicrobial Drugs Used in Reptiles (dosing table). Rahway (NJ): Merck & Co.; accessed 2026. URL: https://www.merckvetmanual.com/multimedia/table/antimicrobial-drugs-used-in-reptiles. Carbenicillin (Antibiotic) has cited veterinary dosing for russian tortoises. Routes documented in russian tortoises: IM. A typical adult russian tortoise weighs 0.23–0.91 kg. ExoticRx lists 1 cited dose rule for Carbenicillin in russian tortoises, drawn from published veterinary references. Verify against current literature before clinical use.

US trade names: Geocillin, Pyopen

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	Indication	Evidence	Source
IM	200–400 mg/kg	q 24 h	—	Weak	Merck Veterinary Manual. Antimicrobial Drugs Used in Reptiles (dosing table). Rahway (NJ): Merck & Co.; accessed 2026. URL: https://www.merckvetmanual.com/multimedia/table/antimicrobial-drugs-used-in-reptiles

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
400	IM	Mader's Reptile and Amphibian Medicine and Surgery, 3rd edTable 127.1	400 mg/kg IM q48h180 Chelonians/PD (Testudo spp.)
100	SC	Mader's Reptile and Amphibian Medicine and Surgery, 3rd edTable 128.1	100 mg/kg SC, IM q72h52 200 mg/kg SC, IM, ICe q24h52
200	SC	Mader's Reptile and Amphibian Medicine and Surgery, 3rd edTable 128.1	100 mg/kg SC, IM q72h52 200 mg/kg SC, IM, ICe q24h52

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 PBPs. Extended-spectrum penicillin with Pseudomonas activity.

Side effects & warnings

High sodium content in parenteral form. May cause platelet dysfunction at high doses. GI upset with oral use.

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

Frequently asked questions

What is the dose of Carbenicillin for Russian Tortoises?

Carbenicillin dose range in russian tortoises, with cited source references: IM 200–400 mg/kg q 24 h. Reference ranges from cited sources — verify against current literature before clinical use.

How is Carbenicillin administered in Russian Tortoises?

Documented routes for Carbenicillin in russian tortoises: IM.

What are the side effects of Carbenicillin in Russian Tortoises?

These are general warnings for Carbenicillin across species; consult the russian tortoise dosing table above for species-specific guidance. High sodium content in parenteral form. May cause platelet dysfunction at high doses. GI upset with oral use.

Why a species-specific page? Carbenicillin pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in russian tortoises — 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.