Dogs may be crucial in the early detection of lung infections after scientists discovered that dogs can detect ultra-low concentrations of Pseudomonas, the commonest cause of lung infection in the life-limiting inherited disease, cystic fibrosis (CF).
The world-first scientific study by Imperial College London and the Cystic Fibrosis Trust has found that Bio Detection dogs trained by the charity Medical Detection Dogs have a very high level of accuracy when asked to identify bacteria associated with serious lung infections.
A major cause of lung damage in CF is infection with bacterial pathogens, the most common being Pseudomonas aeruginosa (Pa), infecting around 60% of the 10,000 UK patients.
Pa can be eradicated but it frequently reoccurs and develops resistance to antibiotics. Chronic Pa is closely linked to faster lung function decline and earlier mortality. The resulting bacterial resistance, allergies and toxicities increase the detrimental impact of the infection and this a particular problem for children with CF, where it is harder to diagnose and treat.
The findings, published in the European Respiratory Journal, show that medical detection dogs can differentiate between Pa and other CF bacterial pathogens by sniffing bacteria grown in a nutrient liquid. The results could prove dogs are a more sensitive or more affordable way of screening for lower airway infection in CF.
Early detection will lead to patients receiving a targeted antibiotic, stopping the bacteria taking hold.
Four dogs were assessed on their ability to identify Pa from other CF bacteria. The bacteria were grown in a lab and then filtered out of the solution which was presented to the dogs. The dogs were trained and tested on customised sample presentation stands and correct identification of Pa samples was rewarded by an auditory click and food.
Once trained, the dogs were presented with Pa-positive cultured samples, other cultured bacterial controls or sterile liquid in random order and a positive indication was rewarded if correct. This was followed by four blind studies with the dogs.
Professor Jane Davies, from Imperial College London, says, “This is a really exciting development. Advanced technology to detect infections, for example in breath, has proved difficult so far. The successful training of the dogs on cultured samples will now be used as the foundation for testing patient samples directly.
“People with CF could ultimately monitor their lung infections from home by sending in samples for the dogs to check. We are very grateful to those with CF, cared for by Royal Brompton Hospital, for providing samples for this project and to the CF Trust for their funding support of the next stage of this project as part of the Strategic Research Centre for Pseudomonas infection.”
Dr Claire Guest, Chief Executive and co-founder of Medical Detection Dogs, said, “The findings of this world-first study into the ability of dogs to detect Pseudomonas are yet another indicator of their remarkable contribution to saving human lives.
“Pseudomonas is a condition that affects thousands of people each year in the UK alone. I can assure them that Medical Detection Dogs is working very hard to find effective, affordable and sustainable ways to manage their condition.
“These trial results are just one more reason why dogs never cease to amaze me. They have a highly sensitive sense of smell, unfailing loyalty to their owners, and the ability to restore hope to many.”
Dr Janet Allen, Director of Strategic Innovation at the Cystic Fibrosis Trust, said, “A quick and easy way of detecting Pseudomonas would make a massive difference to people with cystic fibrosis and their families. Once it takes hold, it requires strong antibiotics that can require hospital stays and often carry significant side effects. Some antibiotic-resistant strains can even cause permanent, life-shortening lung damage.
“We’re delighted to fund the next steps of this work as part of our ‘Personalised approach to Pseudomonas’ strategic research centre, so we can build on this work and help people with cystic fibrosis live longer, healthier lives.”
Medical Detection Dogs is the UK’s leading charity saving human lives by training bio-detection dogs. Just like sniffer dogs, bio-detection dogs have been used in other medical fields such as diabetes research and there is emerging recognition of their ability to detect other life-threatening diseases including some cancers.