An Idiographic Investigation of Diabetic Alert Dogs' Ability to Learn From a Small Sample of Breath Samples From People With Type 1 Diabetes

Objective: There is a growing market for diabetes-alert dogs but little has been published regarding their ability to reliably detect hypoglycemia. We aimed to determine whether 2 dogs could detect hypoglycemic breath samples from people with type 1 diabetes (T1D) and then transfer detection to novel hypoglycemic breath samples. Methods: Breath samples were collected from individuals with T1D during times of normo-, hypo- and hyperglycemia. Two dogs, previously trained (3 alternative forced choice) with breath samples from 3 different individuals with T1D, were presented with 3 breath samples from the same individual: 1 hypoglycemic, 1 normoglycemic and 1 hyperglycemic, and trained to identify the hypoglycemic sample using a “yes/no” procedure. The dogs' ability to transfer detection was then tested by presenting them with a novel sample set from the same individual. Then we tested whether 1 dog could transfer detection of the odour of hypoglycemia by presenting new samples from a different individual. Results: One dog was able to transfer detection of the odour of hypoglycemia to samples from the same individual (specificity 89%, sensitivity 62%), but a second dog was not. Results were inconclusive regarding the ability of 1 dog to transfer detection of the odour of hypoglycemia across 2 individuals. Conclusions: The results suggest that some dogs can be trained to detect hypoglycemic breath of an individual with T1D, but detection may not transfer to novel samples from other individuals. Results should be interpreted with caution, as the dogs were trained with only a small number of breath samples before testing.