Cloxacillin for Cats

Cat · Felis catus · typical adult weight 2.50–7.00 kg

Cloxacillin is dosed at 20–40 mg/kg PO q8h in cats, per Verified against Papich/Saunders Handbook of Veterinary Drugs, 4th Ed, p.210 (2026-08-01).. Cloxacillin is used in cats for Staphylococcal infections. Routes documented in cats: PO. A typical adult cat weighs 2.50–7.00 kg. ExoticRx lists 1 cited dose rule for Cloxacillin in cats, drawn from published veterinary references. Verify against current literature before clinical use.

US trade names: Orbenin, Dry-Clox

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
PO	20–40 mg/kg	q8h	7-14 days	Staphylococcal infections	Extrapolated	Verified against Papich/Saunders Handbook of Veterinary Drugs, 4th Ed, p.210 (2026-08-01).

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Mechanism of action

Inhibits bacterial cell wall synthesis by binding to PBPs. Resistant to staphylococcal penicillinase, providing targeted activity against penicillinase-producing Staphylococcus spp.

Side effects & warnings

Cross-allergenicity with other beta-lactams. GI upset common with oral administration. Primarily used for staphylococcal mastitis in cattle.

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

Frequently asked questions

What is the dose of Cloxacillin for Cats?

Cloxacillin dose range in cats, with cited source references: PO 20–40 mg/kg q8h. Reference ranges from cited sources — verify against current literature before clinical use.

How is Cloxacillin administered in Cats?

Documented routes for Cloxacillin in cats: PO.

How long is Cloxacillin given in Cats?

Cited course lengths for Cloxacillin in cats include: 7-14 days. Duration depends on the indication — match it to the specific dose rule in the table above.

What conditions does Cloxacillin treat in Cats?

Cloxacillin is indicated in cats for: Staphylococcal infections.

What are the side effects of Cloxacillin in Cats?

These are general warnings for Cloxacillin across species; consult the cat dosing table above for species-specific guidance. Cross-allergenicity with other beta-lactams. GI upset common with oral administration. Primarily used for staphylococcal mastitis in cattle.

Other Antibiotic drugs with cat dosing

Amikacin Amoxicillin Amoxicillin Injectable Amoxicillin-Clavulanate Ampicillin Azithromycin Aztreonam Bacitracin Carbenicillin Cefaclor Cefadroxil Cefazolin

Cloxacillin dosing in other species

Dogs

See all species for Cloxacillin See all drugs for Cats

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