AFB Detection Dogs

American Foulbrood (AFB) is a highly infectious disease caused by a primitive, spore producing bacteria. The spores are able to survive for decades in soil. The spore has a tough outer sheath that is particularly difficult to kill – beekeeping equipment has to be autoclaved at 160º C for 12 minutes to kill the spores.

The disease has been in New Zealand since 1877 and under legislative management since 1906. The disease was widespread until after WWI when the government identified the beekeeping industry as a job growth opportunity. A ‘burn on diagnosis’ rule was put in place and the disease has been reasonably well controlled in New Zealand ever since. Current control of the disease depends on self-detection and reporting, which is legally required for all beehive owners, and there is about 0.32% reported infection rate in New Zealand.

Detection primarily relies on visual assessment which means early infections and spores can be overlooked. The management agency audits hives where hotspots of disease are reported, however, as an inspection takes hours and involves taking a hive apart to look at all the frames and components, less than 0.5% of total hives are audited annually. A reliable detection dog could easily inspect every apiary in an area like the Wairarapa within a week. AFB spores are also found in honey boxes which are randomly put out in the field every year and may have come off an infected colony spreading the disease. It is hoped the dogs will also be able to detect spores in these boxes before they are deployed.

But the dog detection method has to be reliable and show rigorous, repeatable results before beekeepers can front levy money for dog training and implementation.  To date, dog detection has been done but it has proved unreliable with a lot of false positives. It’s assumed the present detector dogs were trained to detect stress pheromones or decomposing larvae. Honey-bees emit stress hormones for many different stressors including varroa, and decaying larvae could be attributed to a number of issues.

Pete Gifford is a dog trainer from K9 Search Medical Detection with over 30 years of experience in procuring, breeding and training detection dogs. He has worked with search and rescue organisations, corrections services and the military and trained dogs to detect everything from tobacco, drugs, humans, early stage cancers and other diseases. Pete also trains therapy and assistance dogs and has just launched a trust to pair people with dogs trained specifically for their needs. The trust will allow working dogs unable to be pets to continue a useful and rewarding life.

One day when picking up a foster dog, he was asked if he could train a dog to detect AFB. Pete was soon introduced to Jason Prior at DownUnder Honey. As Pete puts it, it all started with a conversation between a man who knew nothing about bees and beekeeping and a man who knew nothing about training detector dogs.

The men have worked together to achieve funding from MPI’s Sustainable Food & Fibre Futures fund, and APINZ via the Honey Industry Trust and the Southern North Island Beekeeping Group. The funding is to trial better methods for AFB detection with dogs. 

They’ve teamed up with Massey University Veterinary Science researcher Dr Neroli Thomson, and Plant and Food Research apicultural scientist Michelle Taylor. Neroli is developing the scientific methodology, will run the trials, and will be the lead author on the end research report. Michelle is culturing AFB spores for the odour samples as at the core of the project is the use of a sterile pure AFB ‘target odour’ to train and test the dogs. This pure odour is the important point of difference, it means the dogs will only detect the actual bacteria.

During Phase One of the project, Pete identified 4 dogs with the drive and disposition for the work at hand — “It’s all about their play and prey drive” Pete says.  Alongside his standard training room in Kimbolton, Pete has set up a ‘clean room’ with a carousel for the ‘volatile organic compounds’ i.e the odour samples. The room enables testing without contamination odour issues and will be used for the trials in the final phase.

Pete will start training the dogs to systematically check for scents in a series of boxes in his standard training room. From here he will desensitise the dogs to odours associated with the AFB compound delivery, for example the flask and saline solution. Pete explains that pure odours present interesting challenges, “When we smell a roast cooking, we smell Sunday dinner, whereas a dog breaks everything down and can smell the meat, the fat, the carrots, the potatoes, the roasting pan”.

The next phase will be the final selection of two of the four dogs, to train them with the AFB samples. This will be followed by the final testing. Testing will be conducted so that both Pete and the dog will not know where the sample is within the multi bucket. Dog trainers can unconsciously signal to their dogs where a sample is so this blind testing is vital. All trials will be recorded with a CCTV set up.

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Showdown Productions Ltd.   Rural Delivery Series 16 2021