The average dog produces about 124kg of poo every year, but not all of that gets picked up and disposed of properly.
So people living in many residential blocks in the US have had their dogs’ DNA registered on a database, in an attempt to tackle problem poo. If they don’t pick up after their dog, a sample of what’s left behind is sent off to a lab so the perpetrator can be identified.
The company behind the tests says it works well in private, gated communities but what about public parks and pavements?
Could other solutions, such as offering rewards for picking up poo, or posting dog mess backs to the owners, work in the long term?
And we hear how Ontario in Canada is collecting dog poo to turn it into energy.
Presenter: Kat Hawkins
Reporters: Ros Tamblyn and Claire Bates
(Photo Credit: Getty Images)
The great mosquito swap
Every year, it’s estimated that nearly 400 million people around the world are infected with dengue fever, a potentially fatal illness that’s passed on by mosquitoes.
No vaccine is effective at preventing people catching the disease, but what if the mosquitoes themselves were treated to stop them spreading it?
In one city that is severely affected – Medellin in Colombia — an ambitious project is underway to swap wild mosquitoes for a variety that is identical in every way, but with one crucial difference. These mosquitoes have been bred from specimens injected with bacteria that make it impossible to transmit not just dengue, but also the Zika and chikungunya viruses, and Yellow Fever.
Buoyed by successful projects in Australia, the World Mosquito Program is releasing millions of newly-minted mosquitoes across Medellin, in the hope that they will replace the wild population.
And to reassure the public, schoolchildren are being taught to love mosquitoes, and even to breed them — a message that contradicts what they’ve been brought up to believe.
Presenter: Tom Colls
Reporter / Producer: William Kremer
(Photo Caption: The Aedes Aegyptii Mosquito / Photo Credit: Getty Images)
The mums saving each other from a taboo condition
"Get rid of the girl who smells" - this is the reaction thousands of traumatised new mothers face every year. A prolonged or obstructed childbirth can lead to a condition called obstetric fistula, where women are left incontinent, continually leaking urine and faeces. Without treatment they often become socially isolated.
But in Madagascar, some women who have successfully been treated for fistula become patient ambassadors. They travel on foot to remote villages to find and help others with the same condition. They personally accompany them to clinics to get life-changing surgery and support. Afterwards, those women return to their villages and begin campaigning for other women to seek care.
Many medical organisations around the world are waking up to the power of the patient's voice - patient ambassadors can resonate with vulnerable groups in a way that other kinds of outreach can't.
Reporter/ Producer: Amelia Martyn-Hemphill
(Photo Caption: Felicia - a patient ambassador in Madagascar / Photo Credit: BBC)
Can phages save us as antibiotics stop working?
Tens of thousands of people die every year because bacterial infections are becoming resistant to antibiotics. That number is expected to explode, as more antibiotics stop working, making antimicrobial resistance, or AMR, one of the gravest health threats facing humanity.
But could viruses come to the rescue? Bacteriophages, or phages for short, are viruses that infect and kill bacteria. They were discovered 100 years ago and have been used to treat infections for decades in Georgia. But despite their abundance in nature and proven ability to kill infections, their potential has not yet been realised outside the former Soviet Union and Eastern Europe.
Steffanie Strathdee, who stumbled across phages as she tried to save her husband’s life, is now leading a campaign to put phages on the map. But can their use be scaled up from individual and costly treatments to a fully-operational weapon in the war against AMR?
Reporter: Tom Colls
(Photo Caption: A phage under an electron microscope / Photo Credit: University of Leicester)
The digital detectives tackling child sexual abuse
Europol, the EU's law enforcement agency, is taking an innovative approach to solving disturbing crimes.
It holds more than 40 million images of child sexual abuse. In many cases the perpetrators remain at large, and their victims unidentified.
By posting parts of those photos online - with the abusers and their victims removed - they are hoping members of the public can help them find out where the crimes took place, and so trace the perpetrators.
Around the world, ordinary people are combing over the photos, using online tools and local knowledge to uncover fresh clues - and the results can be remarkable.
Sam Judah meets the digital detectives trying to geolocate the places where the photos were taken, and asks Europol how their work can lead to the prosecution of criminals.
Presenter: Kat Hawkins
Reporter: Sam Judah
(Photo Caption: Europol is asking for help identifying this location / Photo Credit: Via Europol)