THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE Volume 14, Number 10, 2008, pp. 1235–1241 © Mary Ann Liebert, Inc. DOI: 10.1089/acm.2008.0288 Canine Responses to Hypoglycemia in Patients with Type 1 Diabetes Deborah L. Wells, Ph.D., 1 Shaun W. Lawson, Ph.D., 2 and A. Niroshan Siriwardena, Ph.D. 3 Abstract Objective: Anecdotal evidence suggests that domestic dogs may be able to detect hypoglycemia in their hu- man caregivers; scientific investigation of this phenomenon, however, is sorely lacking. This study thus aimed to investigate how pet dogs respond to the hypoglycemic episodes of their owners with type 1 diabetes. Methods: Two hundred and twelve dog owners (64.2% female) with medically diagnosed type 1 diabetes par- ticipated in the study. All participants owned at least 1 dog. Each person completed a purpose-designed ques- tionnaire developed to collect information on their dogs’ responses (if any) to their hypoglycemic episodes. Results: One hundred and thirty-eight (65.1%) respondents indicated that their dog had shown a behavioral reaction to at least one of their hypoglycemic episodes, with 31.9% of animals reacting to 11 or more events. Canine sex, age, breed status, and length of pet ownership were unrelated to hypoglycemia-response likeli- hood. Thirty-six percent of the sample believed that their dogs reacted most of the times they went “low”; 33.6% indicated that their pets reacted before they themselves were aware they were hypoglycemic. Dogs’ behavioral responses to their owners’ hypoglycemic episodes varied. Most animals behaved in a manner suggestive of at- tracting their owners’ attention, for example, vocalizing (61.5%), licking them (49.2%), nuzzling them (40.6%), jumping on top of them (30.4%), and/or staring intently at their faces (41.3%). A smaller proportion showed behavioral responses suggestive of fear, including trembling (7.2%), running away from the owner (5.1%), and/or hyperventilating (2.2%). Conclusions: The findings suggest that behavioral reactions to hypoglycemic episodes in pet owners with type 1 diabetes commonly occur in untrained dogs. Further research is now needed to elucidate the mechanism(s) that dogs use to perform this feat. 1235 Introduction P et-keeping is a widespread and well-accepted phenome- non in today’s society. As a nation of self-confessed “ani- mal lovers,” the British public now share their homes with over 9 million cats and 6 million dogs. 1 These animals can play an enormous role in their owners’ lives. As well as providing a source of companionship, emotional support, and enter- tainment, there is now substantial evidence to suggest that do- mestic pets may be able to promote their owners’ health. 2–6 Lately, some attention has been directed toward the abil- ity of companion animals, particularly dogs, to serve as an “early warning system” for certain types of underlying phys- ical ailments in humans. For example, dogs have been shown to be capable of using olfaction to detect the presence of can- cer. In 1989, Williams and Pembroke 7 reported a case of a Border Collie/Doberman Pinscher crossbreed sniffing re- peatedly at a mole on its owner’s leg that later was found to be malignant. Similar anecdotal reports have since appeared in newspapers and scientific journals. 8–10 More recently, Willis and colleagues 11 successfully trained 6 dogs of mixed breed to identify people with bladder cancer using a dis- crimination task. As a group, the dogs correctly identified urine samples from patients with bladder cancer on 22 of 54 occasions; a mean success rate of 41%. Although this proof of principle study has been criticized for methodological weakness and erroneous conclusions, 12 other work, using different methods, has yielded similar results. 13,14 In addition to detecting cancer, there is now mounting ev- idence to suggest that some dogs can reliably predict the on- 1 School of Psychology, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom. 2 Department of Computing and Informatics, University of Lincoln, Brayford Pool, Lincoln, United Kingdom. 3 School of Health and Social Care, University of Lincoln, Lincoln, United Kingdom.