A pioneering study has revealed that specially trained dogs can detect bladder cancer in other dogs through the odour of urine, potentially paving the way for a fast, non-invasive diagnostic method.
Three remarkable dogs—Kizzy, a chocolate Working Cocker Spaniel (pictured above); Jobi, a black Cocker Spaniel; and Marlow, a black Labrador—were trained by the charity Medical Detection Dogs (MDD) to identify canine urothelial carcinoma (UC), the most common form of bladder cancer in dogs. These dogs had previously been trained to detect human bladder and prostate cancer.
Published in Veterinary and Comparative Oncology, the study demonstrated that bladder cancer in dogs emits a distinct odour that trained dogs can identify with up to 90% sensitivity (correct identification of positive samples) and 95% specificity (ignoring negative samples).
A Collaborative Effort
The research, funded by The Kennel Club Charitable Trust, was a collaborative project between Medical Detection Dogs, Davies Veterinary Specialists, the University of Bristol, and the Royal Veterinary College.
Claire Guest, CEO, Co-Founder, and Chief Scientific Officer at Medical Detection Dogs, said:
“We have proven many times that dogs can detect cancer in human samples, so we were confident they could smell it in canine samples too. We are delighted that they were so successful at finding the odour of bladder cancer. This disease is difficult to diagnose using traditional methods, which are often unpleasant and intrusive for dogs.”
“When diagnosed, bladder cancer is often at an advanced stage. This research highlights the potential for a new, early, inexpensive, and rapid diagnostic test that could allow earlier intervention. Dogs are way more than only man’s best friend.”
Why This Study Matters
Bladder cancer can be challenging to diagnose. Symptoms often mimic urinary tract infections or bladder stones, and the invasive methods needed for a definitive diagnosis—such as biopsies—can be costly and uncomfortable for canine patients. Traditional urine sample collection methods, such as cystocentesis, are discouraged due to the risk of spreading cancer cells.
Mark Goodfellow, Head of Oncology at Davies Veterinary Specialists, highlighted the value of this breakthrough:
“Showing that trained detection dogs can aid in the identification of this often-hidden disease adds an extra tool for diagnosing urothelial cancer in dogs.”
How the Dogs Were Trained
Kizzy, Jobi, and Marlow were trained to sniff urine samples placed on metal stands in a controlled environment. They indicated a positive (cancerous) sample by sitting, staring, or standing still, and were rewarded with food or play for both identifying positive samples and correctly ignoring negative ones.
The urine samples used were collected from canine clinical patients at Davies Veterinary Specialists and healthy dogs owned by Medical Detection Dogs’ staff and volunteers.
Isabelle Desmas-Bazelle, who led the study at Davies Veterinary Specialists and is now a lecturer and Co-Head of Oncology at the Royal Veterinary College, explained:
“The dogs demonstrated sensitivity superior to cytology of a free-catch urine sample and comparable to the BRAF test. This suggests cancer cells emit a unique odour pattern, possibly through the secretion of volatile organic compounds. This exciting research could lead to the development of an electronic nose as an additional diagnostic tool.”
A Future in Early Detection
Around one in four dogs will develop cancer during their lifetime, and UC accounts for nearly 2% of all canine cancers. Early detection is crucial in improving outcomes, and this research provides a promising new diagnostic avenue.
Jennifer Millard, Chair of The Kennel Club Charitable Trust, praised the study:
“We applaud the efforts of Medical Detection Dogs, Davies Veterinary Specialists, the University of Bristol, and the Royal Veterinary College for this valuable work, as well as Kizzy, Jobi, Marlow, and other detection dogs whose special noses make such an incredible difference.”
The Road Ahead
The findings open the door to further advancements in cancer detection, including the development of technology like an “electronic nose,” inspired by these canine heroes.
The full study is available online at Veterinary and Comparative Oncology. Read it here.