I still don't understand the fascination people have with the dogs, they are tools to find forensic evidence for processing. Yes the dogs alerted, they did their job in that capacity but didn't identify areas of forensic value. So essentially, what they were brought in for in this case didn't advance the investigation.
The dogs might have had more chance of success had less time elapsed between Madeleine's disappearance and their deployment.
Unfortunately by the time the British dogs were called in there was little chance of finding Madeleine if that was even
a priority as by that time I think the focus of the police investigation was firmly fixed on finding aevidence against a suspect.
Help refused for sniffer dogs
Thu, 24 May 2007
Recently, the police in Portugal declined the offer of help from a British sniffer dog team to find missing 4 year old Madeleine McCann.
Senior British Police officers have encouraged Portuguese teams to use the skills of sniffer dogs that are trained in the UK, as they are believed to be the best.
British dogs, including a Spaniel associated with the National Police Improvement Agency, undergo advanced tracking techniques that can track human scent from several miles. It is known that these dogs can track scents that are as old as 28 days.
A senior UK police officer said, "It is an absolute scandal — time is fast running out for this little girl."
"These dogs have immense capability. Their tracking skills are among the finest in the world."
"The dogs were put on standby to go to the Algarve within days of Madeleine’s disappearance."
"You would expect the Portuguese to make use of the best resources available to them, but they repeatedly ignore the offers of assistance."
He added that these dogs are exception at what they do and they can identify blood on a weapon which has been wiped off.
http://www.dogs.co.uk/news/2007/May/Help-refused-for-sniffer-dogs.html