The hypo alert dogs are trained to alert diabetic owners in advance of low (hypoglycemia) or high (hyperglycemia) blood sugar events before they become dangerous, so their owners can take steps to return their blood sugar to normal, such as using glucose sweets or taking insulin.
The dogs are trained to accompany their owners wherever they travel in the manner as guide dogs and assistance dogs. In the UK the scheme is overseen by Cancer & Bio Detection Dogs. In 2009 a dog named Tinker from Durham City, now deceased, became the first British assistance dog to be officially registered for a type 2 diabetic owner. He was able to give his owner Paul Jackson up to half an hour warning before an attack occurred. (see Tinker and Paul on the right)
The training process is done much like that of a termite detection dog. The dog is rewarded for finding a high blood sugar (it is supposed to smell like tutty fruity gum) or the low blood sugar that is supposed to smell like rusty water or nail polish remover.
The dogs will alert on other diabetics beyond their handler.[more info]
Guiseley Lions raised £5,000 to train one of these dogs and hopefully be placed in the local area.