Diphenhydramine for Cat
Cat · Felis catus · typical adult weight 2.50–7.00 kg
Diphenhydramine is used in cat for Allergic reactions, sedation. Routes documented in cat: PO. A typical adult cat weighs 2.50–7.00 kg. ExoticRx lists 1 cited dose rule for Diphenhydramine in cat, drawn from published veterinary references. Verify against current literature before clinical use.
Trade names: Benadryl
Dose ranges
| Route | Dose | Frequency | Duration | Indication | Evidence | Source |
|---|---|---|---|---|---|---|
| PO | 1–2 mg/kg | q8-12h | As needed | Allergic reactions, sedation | Moderate | Plumb's Veterinary Drug Handbook, 9th Ed |
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These ranges are per kg. Enter your cat's weight to get the precise dose and draw-up volume — unit and concentration math done for you.
Mechanism of action
Competitive antagonist at histamine H1 receptors. Also has anticholinergic, anti-motion sickness, and mild sedative properties.
Side effects & warnings
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 cat may differ from canine / feline reference data — consult the primary citations listed with each rule.
Other Antihistamine drugs with cat dosing
Diphenhydramine dosing in other species
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 cat — 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.