Causes of Motion Sickness
Motion sickness is caused by irregular and unfamiliar motion that disturbs the dog’s organs and sensory pathways of balance. Receptors located in a part of the inner ear called the “vestibular apparatus” normally help an animal process its body position, balance and movements. When stimulated, those receptors relay signals via the 8th cranial nerve to particular areas of the brain - in particular, to an area called the “chemoreceptor trigger zone,” or CRTZ. The CRTZ is one of the areas that control the vomiting reflex. When a dog is riding in a car or other vehicle and is not familiar or comfortable with the sensation of traveling, this pathway is triggered and over-stimulated, causing the dog to develop what we know as motion sickness, or “car sickness.” Some dogs develop motion sickness simply upon the sight of a vehicle, or when they are inside a vehicle even though it is still stationary. This form of motion sickness is probably triggered by fear, based either upon unfamiliarity with vehicles or more likely upon prior unpleasant travel experiences.
Preventing Motion Sickness
Frequently, motion sickness can be prevented by conditioning the dog to travel. Dogs affected by motion sickness may benefit by some or all of the following conditioning concepts and techniques:
- Don’t feed a large meal just before traveling, as that meal may reappear inside of the transportation vehicle shortly after the trip begins. However, it can be helpful to feed the dog a small, bland meal before traveling so that his stomach has something in it to absorb gastric juices.
- Take very short trips when first conditioning a dog to travel. Start with just sitting in the car with the dog. The next time, take a short trip around the block, then maybe to the local convenience store or gas station. Very gradually, increase the length of the car ride, as the dog builds up tolerance and seems more comfortable.
- Allow the dog to see outside the vehicle during travel; in other words, let it look out the window. This has been shown to help alleviate the discomfort of motion sickness in both dogs and people. A dog confined in a plastic crate inside a car cannot really see the outside world. Under those conditions, the dog’s internal sensory balance pathways cannot adjust to the motion of the car and tend to become over-stimulated.
- Provide enough room for the dog to lie down, sit, stand up and turn around. This makes it easier for the dog to maintain its balance and to stabilize stimulation of the vestibular apparatus.
- Keep the vehicle cool and well ventilated.
- Provide short "walkie" breaks every so often during a long trip, so that the dog has an opportunity to get away from the motion of the vehicle fairly regularly. In people, we call this “getting your land legs back.”
A number of other desensitization and conditioning techniques may help dogs with motion sickness – either as aids to prevention or as “treatments” after the fact. Some techniques that may be appropriate, in addition to medical treatment and managed behavior modification, might include massage therapy to reduce anxiety and stress; possible application of acupressure techniques; use of herbal or other non-regulated supplements or “remedies”; or other forms of supportive care which might help to promote relaxation, calmness, confidence and comfort. Some of these adjunct approaches lack controlled studies of their effectiveness and may not have established quality control methods or ways to assess their benefit to dogs prone to motion sickness. However, when a dog is gently, kindly and consistently desensitized to travel, and when it learns to associate travel with positive feelings and outcomes, that dog can quickly become a calm and enthusiastic travel companion. While the details of conditioning approaches are beyond the scope of this article, veterinarians and referral behavioral professionals can discuss them with owners in much more detail. What owners of dogs with motion sickness should know is that help is available.
If necessary, certain medications can also be useful to prevent motion sickness in dogs. Currently, these include a class of anti-nausea drugs referred to as phenothiazine antiemetics. These prescription medications have anti-nausea and sedative effects, both of which can be helpful to prevent the effects of motion sickness. Antihistamines are another class of drugs that can be used with good results to prevent motion sickness in dogs. They provide mild sedation and also help reduce drooling. The attending veterinarian probably will want to assess the dog’s general health before prescribing phenothiazine derivatives or prescription anthihistamines, and before recommending an appropriate dosage for over-the-counter antihistamine medications.
Most young dogs that initially develop motion sickness during car rides eventually grow out of it. Many if not most well-socialized companion dogs enjoy going out and about with their owners, especially if it routinely is a thoroughly positive experience. If a dog associates care rides with unpleasant experiences (going to the veterinarian, getting an injection, being restrained by unfamiliar people, having its owner “abandon” it), it is highly likely that the dog will resent car travel and will try to avoid it at all costs, whether or not motion sickness is involved.