🫁 Antitussive

Dextromethorphan Dosage Calculator for Dogs

Veterinary-guided dextromethorphan (DXM) dosing for dogs with chronic nonproductive cough — including xylitol product warnings and combination drug safety checks.

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XYLITOL WARNING: Many OTC cough syrups (e.g., Robitussin) contain xylitol, which is severely toxic to dogs. ONLY use pure dextromethorphan products with NO xylitol, alcohol, guaifenesin + other decongestants. Read every ingredient label before use.

What Is Dextromethorphan in Dogs?

Dextromethorphan (DXM) is a non-opioid antitussive that acts on sigma-1 receptors and NMDA glutamate receptors in the medullary cough centre. In veterinary medicine it is occasionally used for chronic nonproductive cough in dogs (e.g., kennel cough, collapsing trachea), though its efficacy in dogs is considered modest compared to butorphanol or hydrocodone.

DXM is extensively metabolised via CYP2D6 to dextrorphan, which has greater NMDA receptor activity. Dogs metabolise DXM more rapidly than humans, resulting in shorter duration of action. It is available as 15 mg and 30 mg tablets, and syrups of variable concentration (verify label carefully).

Important Limitations

  • Evidence for efficacy in dogs is limited; butorphanol is more effective for cough suppression
  • NOT appropriate for productive cough (may trap secretions)
  • Avoid in dogs on MAO inhibitors or serotonergic drugs (serotonin syndrome risk)
  • Many combination OTC products contain harmful ingredients — never use multi-symptom products

How to Use This Calculator

  1. Confirm your product contains ONLY dextromethorphan (no xylitol, alcohol, pseudoephedrine, or phenylephrine)
  2. Enter your dog’s weight
  3. Enter the DXM concentration of your product
  4. Click Calculate to see dose range
  5. Always confirm with your vet before administering

🧮 Dextromethorphan Dose Calculator

Dextromethorphan Dosing

References

  1. Plumb DC. Plumb’s Veterinary Drug Handbook, 9th ed. Wiley-Blackwell; 2018.
  2. Papich MG. Saunders Handbook of Veterinary Drugs, 4th ed. Elsevier; 2016.
  3. ASPCA Animal Poison Control Center. Xylitol toxicity in dogs. 2023.