Info from Wikipedia.org

The Labrador Retriever (also Labrador, or Lab for short) is one of several kinds of retriever, a type of gun dog. A breed characteristic is webbed paws for swimming, useful for the breed's original purpose of retrieving fishing nets. The Labrador is the most popularbreed of dog by registered ownership in Canada, the United Kingdom, and the United States (since 1991). It is also one of the most popular assistance dog breeds in Australia, Canada, the United Kingdom and the United States and many other countries, as well as being widely used by police and other official bodies for their detection and working abilities. Typically, Labradors are athletic and love to swim, play catch and retrieve games, are good with young children, elderly, and for protection.

Appearance
Labradors are relatively large, with males typically weighing 29 to 41 kg (64 to 90 lb) and females 25 to 32 kg (55 to 71 lb).  Labradors weighing close to or over 100 lb (45 kg) are considered obese ( Paddy's notes: See green text below in SIZE section of Breed Standards, as the above AKC information does not hold true in the show ring) or having a major fault under American Kennel Club standards, although some Labradors weigh significantly more. The majority of the characteristics of this breed, with the exception of colour, are the result of breeding to produce a working retriever. 

As with some other breeds, the Conformation (typically "English", "show" or "bench") and the Field (typically "American" or "working") lines differ, although both lines are bred in both countries. In general, however, Conformation Labradors tend to be bred as medium-sized dogs, shorter and stockier with fuller faces and a slightly calmer nature than their Field counterparts, which are often bred as taller, lighter-framed dogs, with slightly less broad faces and a slightly longer nose; however Field Labradors should still be proportional and fit within AKC standards. With field Labradors, excessively long noses, thin heads, long legs and lanky frames are not considered standard. These two types are informal and not codified or standardized; no distinction is made by the AKC or other kennel clubs, but the two types come from different breeding lines. Australian stock also exists; though not seen in the west, they are common in Asia.

The breed tends to shed hair twice annually, or regularly throughout the year in temperate climates. Some Labradors shed considerably; however, individual Labradors vary. Labrador hair is usually fairly short and straight, and the tail quite broad and strong. The webbed toes of the Labrador Retriever make them excellent swimmers. The webbing between their toes can also serve as a "snowshoe" in colder climates and keep snow from balling up between their toes- a condition that can be painful to other breeds with hair between the toes. Their interwoven coat is also relatively waterproof, providing more assistance for swimming.

Official breed standards
There is a great deal of variety among Labradors. The following characteristics are typical of the conformation show bred (bench-bred) lines of this breed in the United States, and are based on the AKC standard. Significant differences between UK and US standards are noted.

• Size: Labradors are a relatively large breed. They should be as long from the withers to the base of the tail as they are from the floor to the withers. Males should stand 22.5 to 24.5 inches (57 to 62 cm) tall at the withers and weigh 65 to 80 lb (29 to 36 kg). Females should stand 21.5 to 23.5 inches (55 to 60 cm) and weigh 55 to 70 lb (25 to 32 kg). By comparison under UK Kennel Club standards, height should be 22 to 22.5 inches (56 to 57 cm) for males, and 21.5 to 22 inches (55 to 56 cm) for females.(Paddy's notes: after speaking with a few judges at AKC shows, these weight standards are outdated.  An 80 lb male or a 70 lb female {the largest size within the printed breed standards} would be puney competitors in the Lab category at an AKC show.....winners at the shows are more like 20 lbs heavier than this.)
• Coat: The Lab's coat should be short and dense, but not wiry. The coat is described as 'water-resistant' or more accurately 'water-repellent' so that the dog does not get cold when taking to water in the winter. That means that the dog naturally has a slightly dry, oily coat. Acceptable colours are black, yellow (ranging from ivory or creme to fox red), and chocolate.
• Head: The head should be broad with a pronounced stop and slightly pronounced brow. The eyes should be kind and expressive. Appropriate eye colours are brown and hazel. The lining around the eyes should be black. The ears should hang close to the head and are set slightly above the eyes.
• Jaws: The jaws should be strong and powerful. The muzzle should be of medium length, and should not be too tapered. The jaws should hang slightly and curve gracefully back.
• Body: The body should be strong and muscular with a level top line.
• The tail and coat are designated "distinctive [or distinguishing] features" of the Labrador by both the Kennel Club and AKC. The AKC adds that "true Labrador Retriever temperament is as much a hallmark of the breed as the 'otter' tail."
  
  Colour
   The three primary color varieties of the Labrador Retriever Labrador Retrievers are registered in three colours: black (a solid black colour), yellow (anything from light cream to "fox-red"), and chocolate (medium to dark brown). Some Labrador retrievers can have markings such as white patches on their chest and other areas, but most commonly they are one solid color.
  
  Puppies of all colours can potentially occur in the same litter. Colour is determined primarily by three genes. The first gene (the B locus) determines the density of the coat's eumelanin pigment granules, if that pigment is allowed: dense granules result in a black coat, sparse ones give a chocolate coat. The second (E) locus determines whether the eumelanin is produced at all. A dog with the recessive e allele will produce only phaeomelanin pigment and will be yellow regardless of its genotype at the B locus. The genes known about previously have had their number increased by the introduction of the K locus, where the dominant "black" allele KB is now known to reside. Black or chocolate Labradors therefore must have the KB allele. Yellow Labradors are determined at the E locus, so the K locus is irrelevant in determining their colour. Variations in numerous other genes control the subtler details of the coat's colouration, which in yellow Labradors varies from white to light gold to a fox red. Chocolate and black Labradors' noses will match the coat colour.
  
  Temperament
  The AKC describes the Labrador's temperament as a kind, outgoing and tractable nature. Labradors' sense of smell allows them to hone in on almost any scent and follow the path of its origin. They generally stay on the scent until they find it. Labradors instinctively enjoy holding objects and even hands or arms in their mouths, which they can do with great gentleness (a Labrador can carry an egg in its mouth without breaking it). They are also known to have a very soft feel to the mouth, as a result of being bred to retrieve game such as waterfowl. They are prone to chewing objects (though they can be trained out of this behavior). The Labrador Retriever's coat repels water to some extent, thus facilitating the extensive use of the dog in waterfowl hunting.
  Labradors have a reputation as a very even-tempered breed and an excellent family dog. This includes a good reputation with children of all ages and other animals. Some lines, particularly those that have continued to be bred specifically for their skills at working in the field (rather than for their appearance), are particularly fast and athletic. Their fun-loving boisterousness and lack of fear may require training and firm handling at times to ensure it does not get out of hand—an uncontrolled adult can be quite problematic. Females may be slightly more independent than males. Labradors mature at around three years of age; before this time they can have a significant degree of puppy-like energy, often mislabelled as being hyperactive.  Because of their enthusiasm, leash-training early on is suggested to prevent pulling when full-grown. Labradors often enjoy retrieving a ball endlessly and other forms of activity (such as agility, frisbee, or flyball).
  
  Although they will sometimes bark at noise, especially noise from an unseen source ("alarm barking"), Labradors are usually not noisy or territorial. They are often very easygoing and trusting with strangers, and therefore are not usually suitable as guard dogs.
  Labradors have a well-known reputation for appetite, and some individuals may be highly indiscriminate, eating digestible and non-food objects alike. They are persistent and persuasive in requesting food. For this reason, the Labrador owner must carefully control his/her dog's food intake to avoid obesity and its associated health problems (see below).
  The steady temperament of Labradors and their ability to learn make them an ideal breed for search and rescue, detection, and therapy work. They are a very intelligent breed. They are ranked # 7 in Stanley Coren's The Intelligence of Dogs. The AKC describes the breed as an ideal family and sporting dog. Their primary working role in the field continues to be that of a hunting retriever.
  
  Exploration
  Labradors do not typically jump high fences or dig. But because of their personalities, some Labradors climb and/or jump for their own amusement. As a breed they are highly intelligent and capable of intense single-mindedness and focus if motivated or their interest is caught. Therefore, with the right conditions and stimuli, a bored Labrador could "turn into an escape artist par excellence".
  Labradors as a breed are curious, exploratory and love company, following both people and interesting scents for food, attention and novelty value. In this way, they can often "vanish" or otherwise become separated from their owners with little fanfare. Sadly, many dogs are also stolen. Because of their curious nature and ability to "vanish," along with the risk of being stolen, a number of dog clubs and rescue organizations (including the UK's Kennel Club) consider it good practice that Labradors be microchipped, with the owner's name and address also on their collar and tags
  
  Use as working dogs 
  Labradors are an intelligent breed with a good work ethic and generally good temperaments (breed statistics show that 92.3% of Labradors who were tested passed the American Temperament Test.) Common working roles for Labradors include: hunting, tracking and detection (they have a great sense of smell which helps when working in these areas), disabled-assistance, carting, and therapy work. Approximately 60–70% of all guide dogs in Canada are Labradors; other common breeds are Golden Retrievers and German Shepherd Dogs.
  Labradors are powerful and indefatigable swimmers noted for their ability to tolerate the coldest of water for extended periods of time. Their ability to work quietly alongside hunters while watching for birds to fall from the sky, marking where they land, and then using their outstanding nose to find and retrieve dead or wounded birds has made them the king of waterfowl retrievers.
  The high intelligence, initiative and self-direction of Labradors in working roles is exemplified by dogs such as Endal, who during a 2001 emergency placed an unconscious human being in the recovery position, retrieved his mobile phone from beneath the car, fetched a blanket and covered him, barked at nearby dwellings for assistance, and then ran to a nearby hotel to obtain help. A number of Labradors have also been taught to assist their owner in removing money and credit cards from ATMs with prior training.
  
  The breed is used in water rescue/lifesaving. It continues in that role today, along with the Leonberger, Newfoundland and Golden Retriever dogs; they are used at the Italian School of Canine Lifeguard.
  
  Health
  Labrador pups generally are not brought to the home before they are 8 weeks old. Their life expectancy is generally 10 to 12 years, and it is a healthy breed with relatively few major problems. Notable issues related to health and well-being include:
  
  Inherited disorders
  • Labradors are somewhat prone to hip and elbow dysplasia, especially the larger dogs, though not as much as some other breeds. Hip scores are recommended before breeding and often joint supplements are recommended.
  • Labradors also suffer from the risk of knee problems. A luxating patella is a common occurrence in the knee where the knee dislocates and goes back into place.
  • Eye problems are also possible in some Labradors, particularly progressive retinal atrophy, cataracts, corneal dystrophy and retinal dysplasia. Dogs which are intended to be bred should be examined by a veterinary ophthalmologist for an eye score.
  • Hereditary myopathy, a rare inherited disorder that causes a deficiency in type II muscle fibre. Symptoms include a short stilted gait or "bunny hopping," and in rare cases ventroflexion of the neck accompanied by a kyphotic posture.
  • There is a small incidence of other conditions, such as autoimmune diseases and deafness in Labradors, either congenitally or later in life.
  • Labradors often suffer from exercise induced collapse, a syndrome that causes hyperthermia, weakness, collapse, and disorientation after short bouts of exercise.
• Obesity
   Labradors that like to eat and without adequate exercise, can become obese. Laziness also contributes to this. Obesity is a serious condition and can be considered the number one nutritional problem with dogs. A study shows that at least 25% of dogs in the United States are overweight. Therefore Labradors must be properly exercised and stimulated. A healthy Labrador can do swimming wind sprints for two hours, and should keep a very slight hourglass waist and be fit and light, rather than fat or heavy-set. Obesity can exacerbate conditions such as hip dysplasia and joint problems, and can lead to secondary diseases, including diabetes. Osteoarthritis is common in older, especially overweight, Labradors. A 14 year study covering 48 dogs by food manufacturer Purina showed that Labradors fed to maintain a lean body shape outlived those fed freely, by around two years, emphasizing the importance of not over-feeding.[ Labradors should be walked twice a day for at least half an hour.
  
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