Dogs can also help wake sleepy patients on public transport

Researchers in Belgium also show how dogs can help patients with severe sleep problems.

They describe a 35 year old patient with severe excessive daytime sleepiness. She suffered sleep attacks up to six times a day and sometimes slept up to 16 hours a day.

Until recently, this severe sleepiness considerably hampered her social life and limited her use of public transport, as she usually fell asleep within a few minutes of sitting down.

She'd then wake up at the end of the line and have to fight sleepiness on the way back. Sometimes she'd forget where she started from.

Medication had only a limited effect, so the patient was put in contact with a charity that provides trained dogs for people with visual or hearing impairment.

A dog was first trained to wake the patient in the morning at the sound of an alarm clock, even if this sometimes required 30 minutes of gentle biting. The dog then learnt to wake the patient at the sound of the mobile phone ringing. Eventually, he learnt to wake her up, if necessary, at every metro, tram, or bus station.

This animal companionship has allowed our patient to move around the city efficiently and carry on a social life, say the authors. "The intervention could benefit other patients with similarly extreme and treatment resistant daytime sleepiness," they conclude.