Animals have long been used to help sniff out explosives and drugs, track criminals, and find missing children. Service animals can lower our blood pressure, act as our eyes and ears, and protect us. Over the years animals, and even some insects, have proven that they can also help detect certain medical conditions and cancers, as well as provide important insights and advancements into human conditions.
A dog’s sense of smell can be up to a million times more acute than that of a human. Research studies have found that dogs can use their sense of smell to recognize the differences between normal tissue and cancerous tissue in humans. Evidence suggests that melanoma cells release significant enough levels of chemicals in blood and urine to allow for early diagnosis in patients. When using the same methods as canine scent detection for drugs and explosives, dogs demonstrated impressive accuracy in localizing the melanoma tissue.
Dogs have also shown the ability to detect early stages of colon cancer. A study on a Labrador Retriever who was trained in cancer scent detection correctly identified 91% of breath samples and 97% of stool samples from patients with colon cancer. These types of studies could eventually lead to less invasive colorectal cancer screening alternatives to the colonoscopy.
While not your typical “pet”, pigeons have recently gotten the spotlight for their uncanny contributions to medicine. Pigeons, which share many visual properties with humans, could help scientists make advances in breast cancer research according to the research article "Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images.” These pigeons do more than just eat bread crumbs. Through food reinforcement training, the pigeons had a remarkable ability to distinguish malignant and benign tissue and were able to apply their knowledge to images they'd never seen before. While pigeons will thankfully not be replacing radiologists or pathologists, the findings suggest that pigeons may help to supplement human subjects in certain medical studies.
As it turns out, those pesky flies that are always going after your bananas do have some benefits. In a recent study, researchers used genetically engineered fruit flies to detect breast cancer. The flies’ neurons would fluoresce under a microscope when activated by odor molecules from breast cancer cells. When air samples were released across the antennae of fruit flies, each individual strain of breast cells activated a unique pattern among the flies’ neurons. The study may contribute to the development of a fast, inexpensive, and highly-efficient pre-screening method that can detect cancer cells in humans.
These types of animal-based studies, while certainly impressive, aren’t being used as the basis of diagnoses but rather to supplement and improve current screening systems. And until dogs develop opposable thumbs, they won’t be using our mobile charge capture or HIPAA compliant text messaging anytime soon. While we don’t advise replacing your health insurance plan with a trip to the local pet store, it’s remarkable how our closest animals can help in the most unlikely of places.