Dogs have a natural ability to track things down using their amazing sense of smell – that’s a fact. Did you know that our canine companions have a staggering 300 million olfactory receptors in their noses and that their brains are 40 times more devoted to analyzing smells, compared to us humans? It’s no wonder they can detect smells we can’t even dream of!
It’s the combination of their ultra-keen noses and their desire to serve that makes man’s best friend perfect for training pretty much any scent you can think of. If they can be taught to sniff out bombs or drugs or find people buried under rubble or snow, what else can they be trained to do?
Meet the ‘Rot Hounds’
Labradors Sam, Wilson, and Yan are professional sniffer dogs, one of a very select group of working dogs that have been trained specifically to search for rot fungus. Adopted from the Blue Cross animal charity by renowned building pathologists and listed building surveyors Hutton + Rostron, these ‘rot hounds’ are now regularly deployed to sniff out dry rot in old and historic properties around the country. Their excellent noses have already been instrumental in saving many listed buildings – including Windsor Castle and some important National Trust properties – from falling into disrepair.
Sam (left) and Wilson (right) with their handlers
What is Dry Rot?
Dry rot – Serpula lacrymans – is a type of fungal timber decay that attacks buildings. It flourishes where there’s damp and moisture and has a distinct ‘mushroomy’ odor. If left undealt with, dry rot will cause timber deterioration, decay and, ultimately, structural failure.
Unfortunately, by the time the smell of dry rot is detected by humans, the fungus is already well into its life cycle, producing masses of mycelium and fungal fruiting bodies. When dry rot has reached this stage, significant damage to the affected timbers is likely to have occurred.
How can sniffer dogs help?
The dogs are brought in at the early stages of fungal detection. Their ability to smell the rot can alert building professionals to locate the exact source of the problem before it is visible to the human eye, meaning it can be treated before it spreads and causes major damage to the building.
Rothounds literally sniff the air for signs of the living fungus before tracking down outbreaks in inaccessible places such as behind panels, in roof spaces and building voids, under floorboards and in cellars. Without any intrusive or expensive work to investigate and expose the scale of the building problem, the dogs provide a simple and effective, non-destructive technique.
What’s more, because the hounds can detect outbreaks of dry rot long before they are found by conventional methods, it is often possible to retain the structural integrity of the original timbers, with considerable savings in terms of building works.
How to Train a Dry Rot Sniffer Dog
While it may take 2 to 3 weeks to train any dog to locate a specific scent, dry rot training takes much longer – at least 6 months. Interestingly, training a rothound does not revolve around food rewards; instead, it focuses on the search being part of the game, while the reward is extra playtime and praise from the dog handler.
Sam’s handler, Peter Monaghan, reported that it took around 2 years to train his dog, using similar techniques to those used by police dog handlers. “You build up a dog’s hunting ability by making it look for a toy. Then you introduce the scent of dry rot to the toy, then you take away the toy and work with actual dry rot in an affected area. The final stage is a blind run where someone else puts the scent down, just to make sure the trainer is not giving off any signals that might help.”
In Sam’s case, he becomes motionless when he detects the scent of dry rot in the air, then drops to the floor with his nose and heads off in the direction of the scent, able to locate rot behind masonry or concealed timber if necessary.
Potential sniffer dogs should have the characteristics of a natural hunting or working dog including a good scenting ability, a tendency to be single-minded and a willingness to work. Crucially, rothounds must be able to operate safely in specialist buildings including historic homes filled with expensive furniture and delicate antiques, hospitals full of people or busy industrial areas with noisy machinery. “It’s very important not to cause any damage to a building […] and Sam is calm, focused and will go about his work carefully and quietly,” adds Peter Monaghan.
The ideal age for training a rothound is 2 to 3 years when they are fully mature yet still young enough to bond with their trainer.