It's rather easy for most humans to get dizzy.

Children playing in a grassy area on warm day will often twirl around and around until they get so dizzy they fall down laughing. If you watch a puppy chasing his tail, the movements are similar, yet the pup doesn't ever fall down. So dogs must not get dizzy, right? Wrong. Dogs don't get dizzy from that type of movement, but they can get dizzy. Some signs your dog is dizzy include losing his balance and falling over, tilting his head, nausea, vomiting, and eyes flicking from side to side. Walking in circles can be another sign your dog is dizzy. Dogs get dizzy from a variety of reasons, including:

Strokes

Though strokes in dogs are rare, they can happen from blood clots, a head injury, some types of illness, and even worms. They are more common in older dogs.

Vestibular Syndrome

The vestibular system gives dogs (and many other mammals) their sense of balance. If this system is out of whack, your dog can get dizzy. Often these symptoms come on suddenly and can be mistaken for a stroke. Ear infections are often an underlying cause of this affliction.

Ear Infections

Inner ear infections are a common cause of dizziness in dogs. Along with tilting their heads and walking in circles, a dog with an ear infection may shake his head a lot. He may also paw at or scratch his ears. The inside of one or both of his ears may be very red, there may be a discharge, and you may smell an odor coming from his ear or ears.

Injury

Your dog may have had an injury either to his head or inner ear that's causing the dizziness. Since your dog can't tell you in words that he hurts, you need to watch for symptoms. Some doggy pain signals include heavy panting, enlarged pupils, a change in appetite, not wanting to lie down, slower reflexes, and licking or biting the affected area. He may want more attention from you or may even wag his tail more than usual.

Tumors

Brain tumors can cause not only dizziness, but also seizures, changes in behavior, head tremors, any of the signs of pain discussed above, or a multitude of other symptoms. Most brain tumors occur in older dogs, but can also occur in younger dogs, especially in Boston Terriers and Boxers.

Other Causes

Although there are a number of reasons your dog may be dizzy, all of them are serious, and may be potentially fatal. Poisoning can cause dizziness in dogs. Encephalitis (swelling or inflammation of the brain) can cause dizziness. Your dog can get encephalitis from a number of causes including infections and tick-borne diseases. If you see any of these symptoms in your dog, take him to the vet. Having the underlying problem diagnosed and treated quickly is the best course of action for a good recovery. Sometimes a person who acts a little quirky is referred to as being "dizzy." If your dog is silly and acts like a clown, enjoy his fun personality for what it is. But if he truly begins to act dizzy, take him to a vet as soon as possible: that's your dog's way of asking for your help.