Ebi, a ten year old female Collie/Labrador cross who gave a remarkable demonstration of the ability of dogs to warn humans of danger.
Podcast Podcast: How the companionship of animals can help humans, plus new controls on the sale of dogs in pet shops | Spirit Radio
Please note that I am unable to answer veterinary questions in comments. If you have questions or concerns about your pet's health it is always better to contact your vet.