Dextromethorphan (Benylin, Robitussin)
Veterinary & Aquatic Services Department, Drs. Foster & Smith


Dextromethorphan is used to treat chronic, dry cough in dogs and cats, under the direction of a veterinarian. Do NOT use for productive coughs. Do NOT use products which also contain acetaminophen, caffeine, or other additives. Contact your veterinarian if your pet experiences excitement, nausea, dizziness, drowsiness, or decreased rate of breathing while taking dextromethorphan.

Generic Name

Brand Names
Benylin, Robitussin, St. Joseph Cough Suppressant for Children, Vicks Formula 44 Soothing Cough Relief

NOTE: Read all ingredients thoroughly, as some formulations of the product may not contain dextromethorphan and some forms may contain other ingredients which may be deadly to animals.

Type of Drug
Cough suppressant

Form and Storage
Tablet or liquid
Unless otherwise specified by the manufacturer, store at room temperature.

Indications for Use
Treatment of dry, nonproductive cough and chronic bronchitis.

General Information
Not FDA approved for use in animals, but it is an accepted practice to use dextromethorphan in specific cases. Available over the counter. Dextromethorphan works by suppressing the cough center in the brain. It does not cause profound sedation like the narcotic cough suppressants can. Do NOT use cough suppressants in animals that have a productive, moist cough, as the body needs to be able to rid itself of the phlegm and other secretions in the lungs. Cough suppressants are most useful in dogs with a dry, hacking cough like kennel cough or a cough secondary to a collapsing trachea. Cats with chronic bronchitis may benefit from a cough suppressant. Chronic coughing irritates the respiratory tract causing more coughing. The goal of the treatment would be to stop the coughing enough to allow the inflammation and irritation to decrease and stop the cycle.

Usual Dose and Administration
Dogs and Cats: 0.25-1 mg/pound by mouth every 8 hours.
Duration of treatment depends on reason for treatment and response to treatment.
Do NOT use products containing acetaminophen, caffeine, or alcohol, as these may be deadly to pets. Consult your veterinarian before using over the counter medications to make sure you have the right formulation.

Side Effects
May see nausea, vomiting, dizziness, or drowsiness.

Do not use in animals hypersensitive (allergic) to it.

Do not use a cough suppressant without first contacting a veterinarian.

Do not use products containing acetaminophen, caffeine, alcohol, or other medications, as they may be deadly to pets.

Use cautiously in animals with allergies because in humans dextromethorphan has been associated with histamine release.

Do not use in pregnant or nursing animals.

Drug or Food Interactions
Do not use within 14 days of using monoamine oxidase inhibitors (MAOIs).

Do not use with other sedatives, narcotics, antihistamines, or central nervous system depressants as effects of the drugs would be increased.

No known food interactions.

May see excitement, confusion, or decreased rate of breathing.

   Click here for the web viewable version of this article.

Click here to email this article to a friend.

Keep this and all other medications out of the reach of children and pets.

If you think your pet has been poisoned...

Contact your veterinarian or one of the Animal Poison Hotlines (listed below) if you think your pet may have accidentally received or been given an overdose of the medication.

**ASPCA National Animal Poison Control Center

1-888-4ANI-HELP (1-888-426-4435). $65.00 per case, billed to caller's credit card.

Follow-up calls can be made for no additional charge by dialing 888-299-2973.

There is no charge when the call involves a product covered by the Animal Product Safety Service.

**Pet Poison Helpline - 24-hour service available throughout North America for pet owners and veterinary professionals who require assistance with treating a potentially poisoned pet.

1-800-213-6680 ($35.00 per incident). Staffed 24-hours a day.

Copyright © 1997-2016, Foster & Smith, Inc. All Rights Reserved.
Reprinted from