Sometimes you might notice your dog shake uncomfortably or uncontrollably, and sometimes your dog goes into “wiggle butt” mode, shaking their lower body in a way that indicates they are happy to see you. The latter is a sign that your dog is a happy and healthy goofball. The former, however, could mean your dog’s shaking could have to do with an underlying disease, severe anxiety, or illness from something like poisoning or distemper.
This basic behavioral movement can be very indicative of dog health. It is important to be able to identify when a dog shake is just a shake, or when the shake is a worrisome tremor.
When Dog Shaking Is a Happy Dog's Shimmy
Dogs will do a body shake as a natural reflex. This reflex is their happy dance.
Maybe you just got home and your pup meets you at the door like a wiggle worm with their tail happily wagging, or you see them do their post-bath dance to quickly dry themselves. The tail-wagging-induced shakes are a normal behavioral sign of emotion.
The post-bath dance of a wet dog is done to shake off the water. When a dog gets wet, they can lose 70% of the water on their fur by shaking their whole body. It's a pretty cool skill that dogs have. Shaking is an efficient way for them to dry themselves in about four seconds.
Why Do Dogs Shake When Scared?
Dogs will sometimes shake out of response to both negative and positive emotions. Your dog may try to hide and shake when scared. When they are in the middle of an anxiety-induced situation like a thunderstorm or fireworks display, for instance, they will literally tremble with fear.
When a dog shakes with fear, they are trying to "shake off" that pent-up, nervous energy they are feeling. The shaking is often accompanied by anxiously panting, pinning back the ears, and tucking the tail between the legs.
If you see your dog shake like this, it is a sign that they are very uncomfortable.
Avoid situations that cause a large amount of stress for your dog, or consider talking to your veterinarian about anti-anxiety medication. You may also want to consult a behavioral dog trainer about desensitizing your dog to their stress triggers.
When Dog Shaking Indicates Disease
Another common reason for dogs shaking is disease. There are a number of medical conditions that relate to a dog’s excessive shaking. These include Addison's disease, generalized tremor syndrome (GTS), epilepsy, and kidney disease. Some dog breeds are more susceptible to these conditions than others.
Generalized Tremor Syndrome
Generalized tremor syndrome (also known as white dog shaker syndrome and responsive tremor syndrome) was first discovered in small dogs like Malteses and West Highland white terriers. Any dog can get GTS, however, no matter what size or breed they are.
There is no known cause for GTS. The syndrome causes full body or localized tremors in young dogs, and it can be treated by corticosteroids like prednisone, which reduces the inflammatory response in the body and suppresses the dog's immune system.
In order to identify if your dog’s shaking is GTS-related, your veterinarian will perform blood or urinary tests to rule out another medical condition like kidney disease. Most dogs recover from GTS within a couple weeks of treatment with prednisone.
Just like human beings, dogs can get Addison's disease, a hormonal disorder that is caused by a deficient production of the adrenal gland hormones cortisol and aldosterone. Symptoms of Addison's disease include shaking, lethargy, weakness, poor appetite, and dehydration.
Addison's is not curable. If your dog has Addison's, your vet will prescribe a medication regimen that helps stabilize their hormone levels. It will take time to find the right dosage for your dog's Addison's disease. Annual blood work is required to make sure the replacement hormone medication is working properly.
Kidney Disease and Kidney Failure
Kidney disease is not entirely treatable, but it is manageable. In addition to shaking, kidney disease may cause your dog to urinate and drink water more frequently. It is most common in senior dogs, as this is a disease that develops over time and does not show until they have reached old age. It is estimated that more than one in 10 dogs will develop kidney disease over a lifetime.
Dogs who have kidney failure likely got it from decreased blood flow or from ingesting toxins like antifreeze, certain medications, or contaminated foods. Treatment includes medication, fluid therapy, dialysis, or diet change, depending on if your dog's kidney problems are acute or chronic.
Seizure Disorders and Epilepsy
Dogs can get epilepsy, a neurological disorder that causes episodes of seizures, which are temporary involuntary disturbances of normal brain function accompanied by uncontrollable muscle spasms.
Dr. Ernie Ward of VCA Hospitals assures pet parents that though the seizure looks serious and will confuse or panic your dog, it is luckily not dangerous or painful. "The important thing is to keep the dog from falling or hurting itself by knocking objects onto itself," he writes. "As long as it is on the floor or ground, there is little chance of harm occurring."
Epilepsy and seizure disorders are treated with anticonvulsant medication, so make sure to consult your dog’s vet if your dog appears to have a seizure.
Why Do Dogs Shake Their Heads?
Ear infection is one of the most common reasons why dogs shake their heads. Check the inside of your dog's ears for inflammation, odor, and ear wax build-up, as these are signs that your dog has an infection such as ear mites. The ear wax will look like coffee grounds.
Mites are treatable with over-the-counter medication that involves regularly pouring an ear solution into your dog's ear canals. Make an appointment with your veterinarian if the mites and head-shaking persist.
Dogs also shake their heads when getting up or wrapping up a stretch. The stretch-and-shake move is an instinctive dog behavior to ensure they are limber and ready to take on the day. Dogs will typically only shake their heads once or twice when stretching. In contrast, dogs who have an ear infection will shake their heads often throughout the day due to the irritation.
Why do dogs shiver? They might be too cold in the winter months, or the shivering could be a result of having ingested a poisonous substance. There are a number of toxins and poisons that cause shivering or muscle tremors in dogs.
Items that are toxic to dogs include poisonous plants, pesticides, onions, and xylitol, the sugar substitute found in many chewing gums and peanut butters. Remember to always read the ingredient list on any human food you are thinking of sharing with your dog.
If you think your dog has swallowed a potentially poisonous substance, call the Animal Poison Control Center as soon as possible at (888) 426-4435. They are available 24 hours a day, 365 days a year.