Every dog is a good dog. Some are just better helpers than others, and now animal behavior experts have designed a new test that can help spot them early. The researchers published their findings in the journal PLOS One.

Service dog organizations like Guide Dog UK breed lots and lots of puppies every year. But not all those puppies will become guide dogs. Not all puppies want to be, says lead researcher Naomi Harvey of Nottingham University.

"If you've ever owned dogs you will know that every dog is different," Harvey said in a statement. "They have their own characters and personality, which are heavily influenced by their life experiences."

The sooner service dog trainers can separate the service dog candidates from the plain old lay-on-the-couch-and-drool puppies, the better off everyone will be. Being a good service dog requires more than just an aptitude for training; the dogs also have to be calm, focused, and cool under pressure. But accurately determining each puppy's predisposition has been a challenge.

So Harvey and her colleagues created the Puppy Training Supervisor Questionnaire (PTSQ), a behavioral assessment that lets dog trainers get a firm yes or no for each puppy in their care. The questionnaire examines seven key areas of each dog's personality: adaptability, body sensitivity, distractibility, excitability, general anxiety, trainability, and stair anxiety.

The researchers worked with Guide Dogs UK to beta test the questionnaire on 1401 would-be guide dogs. They used the PTSQ when the dogs were five, eight, and 12 months old, then followed up later on to see how each dog had fared.

More than half (58 percent) of the dogs in the study grew up to qualify as guide dogs. About one-quarter (27 percent) were just not cut out for the work, personality-wise, and the others were disqualified for health reasons.

The test accurately spotted small subsets of those future service dogs (8.5 percent) and future dropouts (8.4 percent). While those results may not be overwhelmingly impressive, the questionnaire is cheap, quick, and easy to administer, and it is progress toward more precise screening tests.

Chris Muldoon, the research development manager for Guide Dogs UK, says: "This tool, and the wider research project, is increasing our understanding of dog behavior and temperament to make informed decisions that will shape and improve our training processes."