Dogs may not always look like humans, but we share a lot of the same environmental and genetic factors that cause cancer. And, just as in people, cancer often develops in one part of the body and then spreads to others. The National Cancer Institute (NCI) has long used information from studies of human and pet dogs to improve our understanding of cancer biology and help guide its treatment.
In a series of videos posted on Facebook and TikTok, an unlicensed veterinarian named Andrew Jones promoted fenbendazole—an ingredient in several popular dog dewormers—as a cure for cancer. He claims that his own small-cell lung cancer was cured when he took the medicine. However, his story is not backed by the medical community and has been widely debunked.
NCI experts say there’s no evidence that dog dewormer fenbendazole is an effective cancer treatment in humans. But they say that, in mice, the drug has been shown to disrupt microtubules, which give cells their structure. Targeting microtubules is a common approach to approved cancer treatments.
Dogs can develop many of the same types of cancer that people do, including mammary (breast) tumors and lymphoma. Malignant histiocytosis is a common form of lymph node cancer that can occur in any age or breed of dog, but most often affects larger sport breeds such as German Shepherds, Golden Retrievers, and Australian Shepherds. Lymphoma usually appears as swollen glands (lymph nodes) under the neck, in front of the shoulders, or behind the knee.dog dewormer cancer