sniff out

犬が手術に参加しました。
Lifesaving Service Dog Sniffs Out Girl's Disease, Even in Operating Room

Since she was two months old, Kaelyn "KK" Krawczyk has had a severe form of mastocytosis, which can cause a life-threatening allergic reaction to simple, everyday things – heat, exercise, even exposure to medicines.
Mastocytosis is a rare disease that causes an abnormal accumulation of mast cells in one or more organ systems. When mast cells are activated, they can induce immediate allergic inflammation. The disease is exceedingly rare and has a broad range of symptoms and severity, according to the Mastocytosis Society.
Penn Vet dogs learn to sniff out cancer.
KK needs to be monitored all night long so her parents worry that anything, even hot blankets, might lead to a reaction that causes a fall down the stairs, unconsciousness or worse.
But for the last 18 months, they have a much better medical watchdog: a terrier named JJ who can smell the cell changes before she has a serious reaction and warn her parents that she needs her medical kit.

http://abcnews.go.com/Health/service-dog-sniffs-girls-disease-operating-room/story?id=21279329

『Wisdom英和辞典（第三版）』（三省堂）で調べると「かぎつける，見つけ出す」という意味でした。出樹に加わった犬はガンに変化した細胞を嗅ぎ分けて場所を教えてくれるとのことです。犬は人間に対して様々なサービスを行っていることが改めて分かりました。（Ume）