Can a dog really predict an epileptic seizure?

By: Alia Hoyt
Baby, who played the part of canine hero Lassie in the TV show and actor Jon Provost in a promotional photo from 1959. See more dog pictures.
Gabi Rona/CBS Photo Archive/Getty Images

Many fictional dogs, such as Lassie, Benji and Rin Tin Tin, have made their marks on the small and silver screens, sometimes inspired by heroic actions of dogs in real life. Most of the time, these canines completed physical acts of bravery. Service dogs like seeing-eye dogs, recovery dogs and other rescue animals are trained. But is it possible that some dogs are so intelligent and sensitive that they can predict health crises like epileptic seizures and warn their owners?

Epilepsy is a neurological condition with a wide array of possible causes. Involuntary seizures are the most well known characteristic of epilepsy, which is often caused by brain malformations or tumors, head trauma and a variety of other diseases that cause lesions on the brain, according to Nancy Meers, Pediatric Nurse Practitioner with the Children's Epilepsy Center at Children's Healthcare of Atlanta at Scottish Rite. For most epileptics, the truly terrifying thing about seizures is how unpredictable and dangerous they can be.


Many people believe seizure alert dogs (dogs that sense and warn their masters of upcoming seizures) or seizure response dogs (dogs that provide assistance to their masters during and after a seizure) can provide epilepsy patients with a greater sense of control over their disorder because they seem to be able to help them avoid catastrophe in public places, such as driving a car. While many medical professionals do not doubt that there are dogs with the ability to predict seizures, they are wary of relying on them 100 percent. After all, dogs are not infallible, much like their human masters.

Owners of seizure alert dogs report that their canine companions typically begin warning them of impending seizures anywhere from 30 seconds to 45 minutes prior to an episode. Each dog has its own style of alerting, including pawing, barking, circling and making close eye contact. Usually, the canine cues spur the patient to lie down in a safe place until the seizure has taken its course. Seizure response dogs have even been known to lie down next to or on top of the person having a seizure, providing their owners comfort and preventing unintentional injury.

It's impossible to know how many seizure dogs there are in the world, especially because they do not seem to be age-, gender- or breed-specific ­[source:]. In fact, many owners report that pooches they have had for years seem to develop the capability sometime after their owners have been diagnosed.

On the next page, we'll look at some theories of why dogs are capable of detecting seizures and why some experts take the dogs' predictions with a grain of salt.



Detection Dilemmas

Mitch Peterson and his seizure response dog London
Courtesy Canine Assistants

There are some good reasons why few medical professionals doubt that there are dogs that can predict epileptic seizures. After all, animals are very sensitive to subtle physical and biological cues that most humans don't notice. Unfortunately, little research has been done to prove how these dogs are able to predict seizures. One popular theory is that a dog's superior sense of smell helps to predict an imminent seizure. Others believe that dogs are more sensitive to body language than humans, so they can pick up on tiny changes in behavior and movement that occur prior to seizures.

Many medical experts cringe at the claim that dogs can be trained to detect and alert people before seizures occur. They assert that the behavior simply cannot be taught. Organizations such as Canine Assistants, for example, train seizure response dogs to summon help during a seizure, stay with the person and even fetch a telephone if needed. The group stops short of providing seizure alert dogs, however, saying that some dogs may develop the capability of predicting seizures after being placed with a patient.


Most service dog organizations do not guarantee that a dog will alert 100 percent of the time, thus echoing the medical community's hesitance to rely solely on a seizure dog for security. On the flip side, one small study reported in the European Journal of Epilepsy claimed that scientists were able to train dogs to sense seizures through "reward-based operant conditioning." In short, whenever an owner had a seizure, their dog got a treat. So the dogs began to associate the seizures with treats and started to identify the cues ahead of time. The jury is still out on the reliability of this training method, though.

Another kink in the seizure dog research chain happened in early 2007 when two small studies in the journal Neurology reported that four out of seven seizure alert dogs studied turned out to be warning their masters of psychological, rather than epileptic seizures. This may not seem like a big deal, but the two disorders are very different. A 2006 study revealed that up to 30 percent of patients who actually suffer from psychogenic nonepileptic seizures (PNES) are misdiagnosed with epilepsy [source: ScienceDaily]. PNES, which results from emotional difficulties and can often be successfully treated with counseling, rather than unnecessary and harsh epilepsy drugs. The 2007 study also revealed one instance of seizures being triggered by the patient's dog's warning behaviors, indicating another flaw in the reliability of canine seizure prediction.

So how do people acquire seizure response dogs? On the next page, we'll find out.


Obtaining a Seizure Response Dog

Rachel Walz and her seizure response dog Cappi
Courtesy Canine Assistants

Despite the inability to pinpoint why and how seizure alert dogs do what they do, many patients and parents of epileptics want one of their own, if for no other reason other than to have an added measure of security. Thanks in part to the controversy spurred by the misdiagnosed cases of PNES, however, many medical professionals believe that more stringent requirements should be put in place regarding to whom these dogs are given and sold.

Mainly, experts believe that a person who receives a seizure response dog should be a clearly diagnosed epileptic, with PNES ruled out ahead of time. After all, it takes about two years and between $10,000 and $25,000 to train seizure response dogs. Although many medical professionals do not believe PNES sufferers should have a dog to respond to seizures, doctors do recognize that a dog or pet can provide emotional support and improve patients' quality of life.


Epileptics who are fortunate enough to obtain one of these dogs (which insurance usually doesn't cover) are carefully screened to ensure that they can provide the canine with the appropriate care and attention. Owners also must be willing to make the financial commitment, including initial cost of the dog, veterinary bills and other miscellaneous costs. In addition, the dogs need continuous training to keep their skills sharp.

Once a patient acquires a seizure alert or response dog, medical professionals caution patients and their families to remember that even though their dogs are amazing, they're still fallible. Scientists hope that more studies will be done to determine conclusively how and why some dogs have this ability, so that more epileptics will benefit from their abilities in the future.

For more information on dogs and related topics, read on to the next page.


Lots More Information

Related HowStuffWorks Articles:
More Great Links:
  • Barrow, Karen. "Seizure Dogs Don't Respond to Epilepsy?" New York Daily News. 16 Aug 2007. article4847.htm
  • Canine Assistants
  • Professionals
  • Epilepsy Foundation
  • Martin, Jenna. "Seizure-Alert Dogs - Just the Facts, Hold the Media Hype." 11 May 2004.
  • Meers, Nancy, Pediatric Nurse Practitioner with the Children's Epilepsy Center at Children's Healthcare of Atlanta at Scottish Rite. Personal interview conducted by Alia Hoyt. Apr. 4, 2008.
  • Mott, Maryann. "Seizure-Alert Dogs Save Humans With Early Warnings." National Geographic News. 11 Feb 2004. 0416_030416_seizuredogs.html
  • O'Farrell, Peggy. "An Epilepsy Patient's Best Friend." 24 Sept 2004.
  • Schram, Tom. "Where to go to Find a Seizure Alert Dog." 15 Sept 2003.
  • Warner, Jennifer. "Dogs Respond to Non-Epileptic Seizures." CBS News. 22 Jan 2007. main2387333.shtml
  • Watson, Rita, MPH. "Can Dogs Predict Seizures?" 27 March 2007.
  • American Academy of Neurology. "Clues Help Identify Psychological Seizures." ScienceDaily 13 June 2006. 23 April 2008
  • American Academy of Neurology. "Dogs May Be Responding To Psychological Seizures, Not Epilepsy Seizures." ScienceDaily 23 January 2007. 23 April 2008