Meclizine Side Effects in Dogs

Meclizine, sold under the brand name Bonine, is a human antihistamine that helps control canine motion sickness symptoms. Although it is not officially registered for veterinary use, it can be prescribed legally by your veterinarian as an extra-label drug for your dog. This means that veterinarians can give this medication to their non-human patients since animals on not listed on the label as U.S. Food and Drug Administration-approved users of the medication.

For more dogs, meclizine is considered safe, but the medication may cause a few side effects. It can also interact with some drugs and may complicate some pre-existing conditions your dog has. Let’s look at the side effects meclizine could cause in your dog, possible drug interactions and conditions that may not benefit from meclizine use, as well as examining other options to control the symptoms of canine motion sickness.

Meclizine Side Effects in Dogs

As a member of the antihistamine drug class, meclizine may present a certain set of side effects for your dog, most of which are minor. Common side effects can include

  • appetite loss
  • diarrhea
  • dry mouth
  • increased heart rate 
  • lethargy

Drug Interactions and Other Concerns

Meclizine may interact with certain other medications your dog takes, and the interaction could be harmful to your pet’s health. Among the drugs that interact with meclizine are heparin, sedatives and tranquilizers.

Meclizine use may not be recommended if your dog has the following medical conditions:

  • bladder abnormalities
  • enlarged prostate
  • glaucoma
  • heart disease
  • high blood pressure
  • hyperthyroidism
  • liver disease
  • seizures
  • stomach abnormalities

Pregnant and nursing females should avoid taking meclizine because the medication has been shown to cause birth defects and to decrease milk production in lactating animals.

Finally, meclizine can affect the results of allergy skin tests. If your dog needs to undergo skin tests, you will need to work with your veterinarian to determine a medication schedule that takes your pet off meclizine in advance of the test and puts him back on the medication after the test is concluded.

Other Motion Sickness Options to Try

If meclizine has too many side effects for your dog, you may be able to try behavioral options or a natural solution to motion sickness: ginger.

Behavioral options can help retrain a dog with motion sickness to enjoy car travel and have less need for medication. You will need to take him on short rides in your neighborhood, using praise and other rewards when he behaves well, to build his comfort level with car travel. Here are some other tips to help your dog enjoy car rides:

  • Make sure your dog faces forward in the vehicle, rather than looking out the side windows.
  • Open the windows slightly to equalize the air pressure inside the vehicle with the air pressure outside.
  • Keep your vehicle cool and well-ventilated when your dog is in it.
  • Limit the amount of food your dog eats before he gets in the vehicle.

If retraining doesn’t do the trick, consider giving your dog some ginger prior to a car trip. Ginger has long been recognized for its stomach-soothing properties, and you can give your dog ginger capsules, ginger tea or even a gingersnap or two.