A British schoolgirl with a unique type of epilepsy could trigger a life-threatening fit just by laughing.
Millie Webb, nine, has refractory epilepsy, which means heightened emotions - including happiness - can trigger a seizure, which is dangerous if she's alone.
Playing with friends and attending children's birthday parties and even splashing about in the family paddling pool have all triggered fits in the past.
Millie, from Great Sankey, Cheshire, suffers up to 50 seizures a day, any of which could put her life at risk if she were alone and to suffer a serious head injury, choke on saliva produced during fits or drown.
She has now forged a potentially life-saving bond with one-year-old pet pooch Elmo who has appeared to predict the onset of a fit before it happens.
Dad-of-five Stuart Webb, 45, said: "Having lots of fun, such as having a fantastic time playing with her friends at a party, and laughing can trigger a seizure.
"When she was younger it was easier as she didn't want to be out and about but now she wants to play out in the streets with her friends and live life to the full.
"Sometimes we just want her to sit and watch TV but she loves the outdoors and wants to be outside with her friends on her bike and her roller skates.
"This summer she was in the paddling pool with her brother Ellis and she had a fit.
"She went under water and he grabbed her and lifted her out.
She was out of it for 15 minutes.
"We keep an eye on her while she's out and want her to be happy. If she's laughing and smiling it means she's having fun."
Millie's parents Linda and Stuart are now desperate to harness Elmo's talents by finding a dog trainer who can transform the bichon frise into a fully-fledged seizure assistance dog.
Engineer Stuart said: "We've had Elmo since she was a puppy - our other bichon Cookie is her mum.
"When Millie goes into a convulsive seizure she makes strained wailing noises which draws Elmo's attention.
"She constantly licks her face to stimulate her and try and bring her round. It also helps to remove excess saliva produced during the fit and prevents her from choking.
"Back in June Millie was having a bad day and was wiped out on the sofa asleep - Elmo was curled up at her feet and never left her side.
"She suddenly climbed up and licked at her face. Linda tried to shoo her off so as not to disturb Millie, but the next thing we knew she went into a fit.
"It was the first time we'd seen Elmo alert us to it before the seizure."
Millie's mum, teaching assistant Linda, was inspired by UK Channel 4's Rescue Dog to Super Dog, which saw six rescue dogs trained to help people with disabilities, to develop Elmo's skills.
Linda, 36, said: "I got in touch with the show who put me in touch with some dog charities.
"I've been advised to contact my local training centre but I'm not getting anywhere at the moment.
"Elmo doesn't need to be trained in how to pick up on seizures, she already has that, she just needs the proper training to alert us."
Doctors have been left baffled by Millie's "unique" form of epilepsy as medication doesn't seem to help control the seizures which present themselves in a variety of forms.
Stuart said: "Millie is under a specialist team at Alder Hey and also has support from a local epilepsy nurse - they're absolutely fantastic.
"The doctors are completely amazed at the various seizures she has.
"She can have anything from a few seconds of absence right through to tonic-clonic convulsive fits."
Millie has tried 12 different types of medication over the last five years since symptoms first appeared but none of them had any impact on the number or type of seizures she has.
Linda said that the family were incredibly proud of how Millie copes with the condition.
Linda said: "Millie is amazing, she doesn't stop. She has this amazing strength and doesn't let the epilepsy get her down.
"As soon as she's able to get up after a seizure she does - she just wants to be normal - and as much as we can we try not to stop her.
"If Elmo was trained she could go anywhere with her and be even more of a reassuring presence.
"We think Elmo's got the gift to help Millie - we just need someone with the experience to teach her."
To support Elmo's training visit gofundme.com.