Cancer remains a significant health concern for both humans and dogs, with studies indicating that between one-third and one-half of all dogs will develop cancer during their lifetime. Hemangiosarcoma, a malignant cancer originating from blood vessel cells, is particularly challenging because it often goes undetected until a dog suddenly collapses. There are currently no early diagnostic tools for this disease, and the prognosis after diagnosis is typically poor.
Researchers led by Cynthia M. Otto at the School of Veterinary Medicine have explored whether hemangiosarcoma emits a unique scent that trained dogs can detect. Their findings have been published in The Veterinary Journal.
Clara Wilson, a postdoctoral research fellow at Penn Vet's Working Dog Center, explained the science behind canine detection: "We're picking up on volatile organic compounds every time we smell something," she said. "The dogs have an ability to detect them at much lower levels than we can. These compounds are important because they seem to be the key to how dogs are able to smell things like cancer."
Five bio-detection dogs with prior training in identifying odors linked to diseases such as chronic wasting disease, post-traumatic stress disorder, human ovarian cancer, and human pancreatic cancer participated in double-blinded tests. The study involved blood serum samples from three groups: dogs with confirmed hemangiosarcoma, diseased controls (dogs with non-cancerous diseases other than hemangiosarcoma), and healthy controls. Each dog evaluated 12 matched sample sets across seven trials per set. Importantly, none of the test samples had been used during the initial training sessions.
The results showed that the dogs correctly identified hemangiosarcoma samples 70% of the time across all trials. Wilson noted that this accuracy rate is consistent with previous studies involving canine detection of human cancers: "This is very encouraging," she said. "Detecting cancer is incredibly hard—it's a very complex smell."
The study confirms that hemangiosarcoma has a detectable scent profile. According to Wilson, this proof-of-concept could pave the way for developing mechanical or laboratory tests based on these findings.
Wilson suggested that such a scent-based test could serve as an annual screening tool: "It could flag a potential issue so that the owner could get further testing, such as ultrasound or CT scans," she said. "It could really help catch it early for these dogs where we're just finding it far too late."
Otto added that early detection could prevent the spread of disease: "We could prevent the disease from spreading, because it's the spread that's really devastating." She explained that veterinarians might then consider removing the spleen before rupture or starting chemotherapy sooner to improve outcomes.
Wilson also highlighted potential benefits for clinical research: "Early detection of hemangiosarcoma would also allow researchers to test different therapies in clinical trials," she said. "This is an initial kernel of hope."
Both Wilson and Otto believe future research aimed at turning these findings into practical screening tools may help veterinarians treat affected dogs more effectively and provide opportunities for new treatment development.
