Reviewed by Emma Sterling
“They might be cute but the mess some dogs leave behind is unpleasant and can also be dangerous. That’s why Barking and Dagenham council in East London are doing this: encouraging dog owners to register their pets’ DNA.”
It may sound like a joke, but this clip from BBC Breakfast (6 minutes) covers the story on the latest plans by the East London Borough of Barking & Dagenham to combat the problem of dog mess on the streets. Aside from being unsightly, dog faeces on the street pose a health risk, mainly to young children, who could contract toxocariasis by unintentionally ingesting roundworm parasites after touching mud laced with faeces. Barking and Dagenham spend approximately £2.3million a year cleaning up dog excrement and, in times of austerity, it is increasingly important that this sum is reduced by encouraging people to pick up after their pets.
The borough have partnered with PooPrints®, a company specialising in the genetic analysis of dog waste to give residents the opportunity to have their dog’s DNA stored on a database. This would be of potential benefit to registering owners to allow them to identify their dog if it is lost or stolen. Most importantly, in the context of the story, it will eliminate their pet in inquiries into the identity of any dog whose faeces have been left in the street. If the owner is found, they will be sent a warning letter. If there is a second offense, then they will be fined £80. At the moment, the service is voluntary which could be a problem as some may be unwilling to potentially incriminate themselves. However, the service is free for the first 1,000 dogs, which could provide an incentive, and the suggestion is made that it might be factored into future rent agreements in order to be granted permission to use the local parks.
In the clip we see swabs taken from the cheek of Toby the dog. The reporter says, a little simplistically, that “It takes just a few seconds and Toby’s DNA is now on a database”. The swab is taken from the cheek of the dog, sealed away in a sterile case, chilled/frozen to prevent DNA degradation and then sent to a PooPrints® lab for analysis. At the lab, genomic DNA is extracted from the buccal swab. The next step is using a medium-high throughput ABI 3730 DNA Analyser.
The ABI 3730 DNA analyser microsatellite fragment analysis used establishes the genotypes at 15 loci plus a gender marker giving a high probability of a unique genetic ‘fingerprint’ being produced for each dog which is then stored on the PooPrints® database. A dog’s ‘fingerprint’ from a faeces sample is compared against all the collected buccal ‘fingerprints’ on the database. For there to be a match with another ‘fingerprint’, the genotypes must match at every single allele without discrepancy so there is a slim chance of incurring false positives. The company reports 99.9% accuracy. According to their calculations, the probability that there is an additional dog that matches the dog on their database and the reported match is more than 1 in 4,000,000 (However, PooPrints® admit that there is some difficulty with breed identification as it lends itself to slight variation depending on the strength of the database that the sample is compared against).
In the future PooPrints® could consider using other next generation sequencing (NGS) platforms for DNA analysis. Not only do some of the newest systems allow much higher throughput, with massively parallel sequencing, but they can use nanograms as opposed to micrograms of DNA. This could be useful if there isn’t much DNA available, e.g. in cases where the faeces is particularly old. However, despite dropping prices, equipment and maintenance for NGS is still relatively expensive.
For further reading on the forensic applications of NGS see: Next generation sequencing and its applications in forensic genetics (Forensic Science International: Genetics, subscription required)
For more information on the science behind PooPrints® see: http://www.streetkleen.co.uk/science-behind-pooprints.html
For some, creating a dog DNA database is not the solution to reducing the 1000 tonnes of dog mess left on UK streets every day. It could be hard to police as the owners volunteer their dogs to be on it, and it is mentioned in the clip by chief executive of Keep Britain Tidy, Allison Ogden-Newton, “getting everyone to sign up would be tough”, in particular, those who want to continue dog fouling without being caught. There are perhaps more cost effective ways with dealing with the issue. Some councils around the country are reported to have seen substantial falls in dog fouling using prominent posters simply stating “we’re watching you”.
Leader of Barking and Dagenham council Darren Rodwell remains optimistic about the database. He states that the voluntary sign-up scheme is a pilot and that he hopes eventually being part of the dog DNA database will be a compulsory part of the tenancy agreement. But gathering from the clip, Barking and Dagenham residents need some convincing. A pedestrian asked about the scheme said “it’s not realistic, in all honesty, it’s not gonna work”.
This story was covered previously by The Guardian newspaper (April 2015). Finally, it is worth noting that this is not a new idea. DNA sequencing to identify the dogs responsible for faeces on pavements (and their owners) was advocated as long ago as 1996 (see this Newsweek summary).