The Daggett family was on vacation when "Zeki" kept nudging grandma Karen's armpit area with his snout.
The Chicago Heights woman then noticed a lump.
She said doctors found three cancerous growths in her lymph nodes, and was diagnosed with melanoma.
She had surgery to remove 17 lymph nodes and then completed immunotherapy.
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Dagget is now cancer free! She joined ABC7 with Dr. Ari Seifter, a hematologist-oncologist at Advocate Health Care.
She explained that "Zeki" was not trained to detect cancer, but his unusual behavior alerted her to something she might not have noticed.
Dr. Seifter said it's important to know what is normal for your body and speak up when something changes.
Sadly, "Zeki" died after a battle with spleen cancer.