Meclizine For Dogs – THE Solution for Canine Car Sickness

Photo of author
Updated On

I Love Veterinary blog is reader-supported, and we may earn a commission from products purchased through links on this page, at no additional cost to you. Learn more About Us and our Product Review Process >

Is Your Dog Getting Car Sick? Why? 

If a car ride makes your pet sick to its stomach, then Meclizine for dogs might be your pet’s saving grace. During a car ride, the brain interprets sensory input from the vestibular apparatus in the ear as movement. Still, the body is stationary within the vehicle, so the mismatched signals cause nausea and possibly vomiting.

dog in a car

What is Meclizine for Dogs Used For?

The neural mismatch experienced by the brain can lead to the unnerving sensation of nausea. The conflicting signals release histamine neurotransmitters that signal the stomach to vomit.

Meclizine is an antihistamine medication that downregulates the stimulation of the brain’s vestibular system, inhibiting overstimulation and nausea.  

Meclizine is used off-label in animals because it was initially researched and intended for human use. Many human medications are used off-label in veterinary medicine because of the limited number of animal-specific pharmaceutical companies. The effectiveness and safety of Meclizine are essential to discuss with a veterinarian before you use it in your dogs. 

Signs and Symptoms of Car Sickness in Dogs

These are the common signs and symptoms to expect when your dog suffers from car sickness:

  • Hypersalivation 
  • Panting 
  • Restlessness or pacing
  • Increased swallowing and smacking or licking of lips 
  • Curled back or changes in normal posture 
  • TIght lips curled back or taught facial muscles
  • Stress or widened eyes
  • Whining
  • Vomiting
  • Lethargy or depression

Puppies are often too small or short to see out of a car, and because they also have underdeveloped vestibular systems, they are more likely to suffer from motion sickness. Most dogs grow out of this, but some do not and can even develop travel anxiety due to the negative association with traveling in cars.

dog on a car seat

How do I Give my Dog Meclizine?

Meclizine is available in the following strengths: 12.5 mg, 25 mg, 30 mg, and 50 mg tablets, as well as 25 mg capsules. Meclizine should be taken orally 30 – 60 minutes before travel.

Dosages can be calculated as follows:

0 – 5kg    6.25 mgPO q12-24h (orally/ per mouth 1-2 times daily)
6 – 20kg 12.5 mgPO q12-24h (orally/ per mouth 1-2 times daily)
20kg+ 25 mg PO q12-24h (orally/ per mouth 1-2 times daily)

Try not to feed your pet a big meal before traveling, but if you need to administer the tablet in a type of snack, try to use something that isn’t too rich, and they are used to having as a treat.

Most medications will last between three to six hours if the correct dosage is administered, so be sure not to administer more medication before that time has lapsed, or you risk an overdose.

What Happens if I Miss a Dosage for Meclizine?

This is only applicable if your pet is on chronic Meclizine for vestibular disease. Should you miss the general time, you would have given your pet their medication, give it as soon as possible and give the next tablet between eight and twelve hours later.

Associated Risk Factors and Side Effects on Meclizine for Dogs

Meclizine is an antihistamine that falls in the piperazine class. They have the potential to produce a few side effects associated with anticholinergic symptoms, such as:

  • Drowsiness
  • Xerostomia – dry mouth
  • Urinary retention 
  • Increased heart rate 
  • Elevated intraocular pressure that may exacerbate underlying glaucoma
  • May interfere with lactogenesis in lactating bitches 

Concerns and Cautions When Using Meclizine for Your Canine

Meclizine is a reasonably safe drug to use if discussed with a veterinarian to rule out potential adverse effects. Should your pet fall within the following risk categories, then avoid using Meclizine:

  • Not recommended for use in animals with a known allergy or hypersensitivity to the drug.
  • Not intended for use in animals with spinal problems, glaucoma, prostate gland enlargement, or specific gastric or urinary bladder abnormalities or at risk of urinary retention.
  • Not suitable for use in animals with hyperthyroidism, epilepsy, heart disease, or hypertension.
  • Meclizine is not recommended for use in lactating bitches that are not close to weaning.
  • Not intended for use in pregnant bitches as it can cause congenital disabilities as seen in experimental models.
  • Not suitable for use in animals undergoing allergy medical workups as it may interfere with the diagnosis. 
  • Meclizine is not recommended for use in animals with liver conditions as the activity is prolonged. 

Meclizine for Dogs and Possible Drug Interactions

Meclizine should not be administered concurrently with other tranquilizers as it may lead to an increased level of sedation. Using more than one type of antihistamine at the same time as Meclizine is also not recommended as it could increase the number and severity of the aforementioned side effects

What is Vestibular Disease in Dogs?

Vestibular disease in dogs is a condition that encompasses disorders of the vestibular system. 

The vestibular system is located within the inner ear. It consists of sensors that detect motion and communicate it to a specialized center located in the back of the brain that interprets it. 

Mismatched signals or overstimulation of the vestibular system can cause significant and severe side effects like dizziness, ataxia, and nausea. Animals who suffer from vestibular disease have a markedly altered quality of life depending on the severity of their condition. 

The cause of the vestibular symptoms needs to be thoroughly investigated to ensure that the correct diagnosis is attained. An in-depth clinical history, physical examination, and several diagnostics tests may be required to achieve an accurate diagnosis. 

A clinician will need to determine first if it is genuinely a vestibular dysfunction. If so, the localization of the lesion needs to be determined as either peripheral or central.

Vestibular disease in dogs and cats has several symptoms classified as follows:

Generic vestibular signs

  • Ataxia
  • Head tilt
  • Pathologic nystagmus
  • Strabismus
  • Tachycardia
  • Ptyalism
  • Vomiting
  • Inappropriate urination/defecation

Peripheral vestibular signs when only one side is affected

  • Head tilt toward lesion – the head will lean towards the lesion in the brain. 
  • Pathologic jerk nystagmus – the pupils will move involuntarily from side to side. 
  • Asymmetric ataxia – only one side of the body will not be coordinated on movement efforts.
  • Ipsilateral facial weakness – the side of the face on which the lesion occurs will have weak reflexes or muscle tone. 
  • Overall strength not affected.
  • Normal proprioception – patients know where their feet are and can place them down again if flipped over.

Peripheral vestibular signs when both sides are affected

  • A snake charmer head movement is often observed. 
  • Head tilt may be absent.
  • Nystagmus may or may not be present. 
  • Crouchedor hunched over posture.
  • Bilateral facial weakness.
  • Over strength is not affected. 
  • Normal proprioception – patients know where their feet are and can place them down again if flipped over.

Central vestibular disorders involve vestibular structures found in the caudal fossa of the brain and will have very different neurological deficits.


  • Delayed/absent postural reactions.
  • Other cranial nerve deficits.
  • Weakness.
  • Not to be confused with imbalance.

Paradoxical vestibular disease

  • A unique central disorder.
  • Head tilt and loss of balance opposite side of the lesion.
  • Nystagmus toward the lesion.
  • The side of the lesion is determined by the side of postural deficits, other CN deficits, and/or hemiparesis.

The diagnosis of vestibular disease will require a few tests, which may include

  • Otoscopic examination – if possible.
  • Oral examination – especially in cats.
  • CBC.
  • Biochemistry panel.
  • T4/fT4
  • Clotting times.
  • Urinalysis.
  • Thoracic radiographs.
  • Abdominal radiographs.

Treatment of Vestibular Disease 

Depending on the symptoms, the following medication could be used:

Diazepam0.25-0.5 mg/kg(q30 min x 2 doses, then CRI at 0.25 mg/kg/min)
Acepromazine0.01-0.2 mg/kg (q4-6H prn (3 mg total dose)
Maropitant1 mg/kg
2 mg/kg
SQ q24h 
PO q24h

Supportive care

If a patient is seizing severely or is not drinking or eating, it is advisable to admit them to the hospital to prevent dehydration or severe seizure events. Patients may need to be placed into padded cages with IV fluids, a quiet environment as well as ICU observation.

The prognosis for vestibular disease 

The overall prognosis for the disease is not always related to how severe the symptoms are. Many patients show marked improvement after 24 hours of treatment depending on the initial cause, but they can relapse.

Most patients respond well to medication, and the causes can be treated if it is not related to a neoplastic or inoperable tumor. Unfortunately, tumors tend to have a poor prognosis, and life expectancy is estimated to be one year with an average quality of life. Unfortunately, the potential for recurrence is high.

Where to Buy Meclizine for Dogs 

Meclizine is an over-the-counter medication that can be easily purchased from an online pharmacy or a regular drug store. Remember that the dosages for humans are different from that of dogs – so be sure to consult with a veterinarian if you are unsure of the dosage. 

Also, be sure to check that there are no other additives that are not intended for dogs because the medication is used off-label. For example, additives like xylitol can be very toxic to dogs.

You can also visit your local veterinarian, and they should have meclizine or an alternative to help your dog with their travel sickness or anxiety.

dog in a car seat

Preventing Dog Travel Sickness in Cars

Besides using medication, there are a few easy you can try to reduce motion sickness in dogs:

  • Dogs are less likely to vomit if they aren’t traveling on a full stomach – try not to feed them just before departure or possibly just offer them a small snack and some water to help keep them hydrated and comfortable. 
  • Booster seats are also a helpful way to allow small breed dogs or puppies to be elevated and restrained so that they can see the vehicle’s motion and avoid triggering conflicting signals.
  • Fresh, flowing air – opening a window slightly or the sunroof can create airflow, which can distract your dog and provide airflow to avoid them feeling claustrophobic.
  • Take the time for time-outs – a little bit of a break from the car is beneficial as your pet gets the opportunity to smell and experience new surroundings, relieve themselves, or alleviate the symptoms they are experiencing by giving their conflicted vestibular system a bit of a break.

What to do In Case of Meclizine Overdose

Antihistamines can have severe effects if they are overdosed, so it is essential to contact your closest emergency practice as soon as possible. 

If your pet has accidentally just ingested a whole pack of medication, contact your vet immediately, and if you are far from a practice, ask about ways to try and get your pet to vomit to try and decrease the amount of medication absorbed through the gastrointestinal tract.

Your pet may need to be hospitalized depending on the exact overdose and the extent of the symptoms.  

Can I Give My Dog Human Motion Sickness Medication?

If it works for humans, surely it works for dogs too? Unfortunately, no, this is most certainly not the case. Canine and human physiology may share certain similarities in metabolizing medications, but they also have significant differences. Therefore, the dosages and severity of adverse effects are most important when considering what type of motion sickness medication to give to your dog.

Pharmaceutical companies spend millions researching pharmacokinetics and pharmacodynamics of medications intended for animals, so it is always advisable to try and use medications specifically designed for animals. Maropitant, for example, is the drug of choice for motion sickness in animals, but it will require a veterinary visit to get a prescription. 

Human medications are often used off-label for veterinary patients, but only if a veterinarian has seen them and meets the criteria for using an off-label medication. Antihistamines are readily available at convenience stores, supermarkets as well as pharmacies, and some fuel stations. 

Be sure to read the label of the medication you intend to use and make sure it does not contain any harmful chemicals such as Xylitol which is very toxic to dogs. If your pet has adverse reactions to the medication, discontinue its use immediately and consult your veterinarian.

Sharing is caring!

Photo of author


Dr. Kaylee Ferreira, a South African vet from Johannesburg, excels in diverse veterinary roles. Founder of Kubuntu Veterinary Services, she's a dedicated animal lover and adventurer.