Search Dogs can cover a lot of ground, very quickly. One search dog can search the same area as 10 or 15 people, and do it quicker. Also, a dog can search at night just as well as in the day, because they are using their noses to search, not their eyes. Most of the time people searching find the lost person because the lost person can call out or shine a torch. If the lost person is not able to do this because they are not well, then it's much harder for people searching to find them. It doesn't make any difference to a dog because the lost person is still giving off scent.
This might make it sound as though dogs could replace lots of searchers. That's not the case - they are just another very good way of looking for the lost person.
No one particular breed is or isn't suitable. There are however certain characteristics that are required. The physical size is a factor, and the smallest suitable would be a spaniel and the largest would be a large German Shepherd. Too small, and rough terrain becomes a problem, and too large and the stamina drops away. Popular breeds in New Zealand are Labradors and German Shepherds, but Border Collies and other retrievers also make good search dogs. In other countries, other breeds are favoured. Whatever the breed, the dog must have a working background and have a strong "play-drive"
Well all dogs are the personal property of the handler. The handler chooses a breed he or she likes and then chooses the dog from the litter. With some dogs, it's clear after a short time training that they are not suitable. This is normally obvious to the more experienced handlers, and the dog's handler is advised to get another dog or to be prepared for a long "learning experience" with no guarantee of success.
As mentioned, dogs are the private property of the handler. The handler makes the decision what breed of dog they want and select it themselves from a litter from another breeder. We do not have our own breeding program or specific breeders we use, though often a pup will be chosen because the parent has a good history in Search and Rescus.
Physically, the dog must be sound – that is without any defects or health problems.
Temprementally, they must be non-aggressive, have a high play drive, and have a desire
to go to humans. A dog that is timid will not be suitable. They must be quite
independent and out going. They will be expected to work for extended periods,
with little or no interaction with the handler, so a reasonable level of independence
and self motivation is required.
The dogs are all the private property of the handler.
The younger the better. Training should start as a young puppy at three months of age or so. Starting up to six months of age is feasible, but much older than that and the success rate starts to drop significantly. That is not to say it cannot be done, but the chances of success are much higher when training is started at an early age.
In New Zealand, all the dogs belong to the "handler", and training is the responsibility of the handler (in some European countries I believe it is possible to buy a trained search dog). The handler does all the training. Most of the training has to be done in the handler's own time. Search Dog teams such as SAR Dogs Otago organise regular sessions and at these training sessions, the more experienced handlers try to guide the others, both in what to do to train the dog to do something in particular, and how to sort out a training problem. This training is carried out at various locations - a different one every time. (Dogs have better memories than most people give them credit for, and will remember where people have hidden in the past, and check that spot out from memory, rather than using scent.) However most of the training is done by the handler alone.
This is a huge question, and there are whole books
attempting to answer that.
Essentially however, the dog is at
first rewarded for going to people a very short distance away.
Other required elements (such as barking
when they've found) are added in one at a time, having been taught as
separate tasks, and the dog is praised heavily for doing the right
thing, and only rarely chastised for doing the wrong thing (only
advanced dogs should ever be chastised). The difficulty of the task
is very slowly increased as the dog learns what is required, and the
handler must always be prepared to revert to something easier. If one
extra element is added into the search "sequence", then
everything else is reduced dramatically in difficulty. The dog needs
to want to do this job, so the training must be fun; the dog
eventually will be expected to work very independently for extended
periods of time, and if the dog isn't motivated to do the job, then
that will not happen.
It varies depending on the dog and how much time the handler can devote to training, but generally, three years is about what most take. This could be reduced by intensive training, but most dogs need to be at least 2½ years old to have the ability to concentrate on one task (searching) all day.
Air-scent dogs search off lead, and dogs which follow scent on the ground generally work on a long line
The most common reward is a game with the dog's favourite toy at the end of the search. A few dogs are rewarded with food.
Air-scent dogs alert, or indicate to the handler, a find in a number of ways.
Some will stay with the subject and bark until the handler arrives, some will
return to the handler and bark, and then lead the handler back to the subject,
and others will return to the handler and make a distinctive action (such as
taking a toy of the handler's belt) and then lead the handler back in.
Dogs trained to locate people under avalanches, indicate the find by digging at the site of the burial.
Nutrition is probably more important than most people, including ourselves realise. Certainly the dogs have to be very fit in order to be able to work all day - they need to be athletes of the canine world. Nutrition for athletes is important, so it follows that nutrition for search dogs would be important. Most handlers feed a commercial dried food designed for working dogs. This seems to have been OK for my (now nine year old) labrador. If this is of particular interest to you, I could pass your question onto another handler who has done some studying in this area.
The dogs are tested for suitability to be used on operations by New Zealand Land Search and Rescue Assessors, and a Police Dog Assessor. The civilian assessor (from NZLSAR) and the Police assessor jointly decide on the outcome of the test. The standard that they are tested to is set out in the NZ LSAR published standards. No dog that has not been assessed in this way is eligible to be used on a search. Assessments are held twice a year – once on each island of New Zealand.
All training is the responsibility of the handler. Dogs are reassessed annually, so it is the handler's responsibility to ensure that the skills of the dog improve rather than deteriorate, and thus ensure continued re-certification for operational use. A dog that fails a re-assessment is removed from the list of eligible dogs until it can be reassessed and passes.
The dogs that are fully trained to operational standard provide a good service. What is lacking is numbers. However, operational dogs are prepared to travel to a search anywhere in the country, and dogs from areas where there are a number of operational dogs are frequently called to assist in searches in areas where there are insufficient operational dogs.
Search and Rescue Dogs in New Zealand are responsible to the Police, as are all SAR volunteers.
Handlers are required to have extensive Search and Rescue training, as well as training their own dog, before being certified as operational. NZLSAR provide many training courses to improve the skills of volunteer searchers, and handlers are required to have attended many of these and participated in search exercises and real searches (without their dog) before they are certified as operational with their dog.
International cooperation is awkward in New Zealand in terms of using dogs from other countries or travelling to other countries to assist in searches, because of the strict quaranteen laws in place in New Zealand to prevent the import of unwanted animal diseases, such as rabies.
The dogs are used in any situation where the search controller thinks that they can be a useful resource in the search. This ranges from and urban search for a missing child, to a mountainous search in heavy bush for a missing hunter or hiker. Frequently the dogs are called as a first resource, due to the potential they have for reducing the number of resourrces required.