Pocket Pet · Rattus norvegicus var. domestica · typical adult weight 0.25–0.70 kg
Diphenhydramine is dosed at 1–2 mg/kg PO, SC q12h in pet rats, per Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Mined from Carpenter's Exotic Animal Formulary, 6th Ed, p.796 (2026-08-01, PENDING REVIEW). Diphenhydramine is used in pet rats for Antihistamine; anaphylaxis. Routes documented in pet rats: PO, SC. A typical adult pet rat weighs 0.25–0.70 kg. ExoticRx lists 1 cited dose rule for Diphenhydramine in pet rats, drawn from published veterinary references. Verify against current literature before clinical use.
US trade names: Benadryl
| Route | Dose | Frequency | Indication | Evidence | Source |
|---|---|---|---|---|---|
| PO, SC | 1–2 mg/kg | q12h | Antihistamine; anaphylaxis | Moderate | Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Mined from Carpenter's Exotic Animal Formulary, 6th Ed, p.796 (2026-08-01, PENDING REVIEW) |
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These ranges are per kg. Enter your pet rat's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Competitive antagonist at histamine H1 receptors. Also has anticholinergic, anti-motion sickness, and mild sedative properties.
Sedation common (first-generation). Anticholinergic effects (dry mouth, urinary retention). Ensure product does not contain xylitol or pseudoephedrine. Dogs and cats. Less effective than second-gen antihistamines for pruritus.
Species-specific contraindications and adverse-reaction reports for pet rats may differ from canine / feline reference data — consult the primary citations listed with each rule.
Diphenhydramine dose range in pet rats, with cited source references: PO, SC 1–2 mg/kg q12h. Reference ranges from cited sources — verify against current literature before clinical use.
Documented routes for Diphenhydramine in pet rats: PO, SC.
Diphenhydramine is indicated in pet rats for: Antihistamine; anaphylaxis.
These are general warnings for Diphenhydramine across species; consult the pet rat dosing table above for species-specific guidance. Sedation common (first-generation). Anticholinergic effects (dry mouth, urinary retention). Ensure product does not contain xylitol or pseudoephedrine. Dogs and cats. Less effective than second-gen antihistamines for pruritus.
Why a species-specific page? Diphenhydramine pharmacokinetics differ across species: dose ranges, intervals, and route preferences are not interchangeable. Cross-extrapolation from canine doses is unsafe in pet rats — 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.