Pet Life Style

Friday, January 29, 2010

Dominance Behavior

It is believed by some that dogs establish a dominance hierarchy through aggressive play and roughhousing along a continuum of dominance and submission, although the concept of social hierarchies in dogs is unproven and controversial.

It is important for successful socialization that puppies participate with their littermates in learning to relate to other dogs. Dogs learn to successfully relate to other dogs by keeping the peace, rather than by constantly fighting to reestablish this hierarchy.

Although dogs are commonly characterized in terms of their dominance (e.g., "Fido is very alpha."), there is some controversy as to whether dominance is a stable personality trait.

In wild wolf packs, displays of dominance have been observed to include "licking up," which involves essentially begging for food; "pinning," in which the dominant dog appears to threaten another, which shows submission by rolling over; "standing over;" territorial marking; and more passive expressions of body language, including holding the tail and ears erect, looking directly at other dogs, circling and sniffing other dogs, growling if the other dog moves.

Submissive displays mirror dominant displays and include adopting a posture that is physically lower than other dogs, such as crouching, rolling over on the back and exposing the abdomen, lowering the tail (sometimes to the point of tucking it between the legs), flattening of the ears, averting the gaze, nervously licking or swallowing, dribbling of urine, and freezing or fleeing when other dogs are encountered.

In wolves, recent research has indicated that dominant behaviors have been misinterpreted as personality traits that determine the inidividual's place in a linear hierarchy in the pack. In contrast, Mech (see recent research, below) argues that packs are family units, and that the "alpha" of a pack does not change through struggles for dominance. Rather, he argues that the family unit serves to raise the young, which then disperse to pair up with other dispersed wolves to form a breeding pair, and a pack of their own. This model undermines the popular conception of dominance in wolf social behavior.

Research on canine familiaris has also questioned whether dominance is a personality trait. Svartberg and colleagues (2002) gathered behavioral data from 15,000 dogs of 164 breeds in attempt to identify major personality traits.

In an approach similar to those used in humans, the authors performed a factor analysis of their data, and identified five major traits: "Playfulness," "Curiosity/Fearlessness," "Chase-proneness," "Sociability," "Aggressiveness." A similar analysis by Goddard and Beilharz (1985) revealed two major factors in social behavior: "Confidence," and "Aggression-dominance."

These studies suggest that dominance, per se, may not be a personality trait. Rather, underlying personality traits such as aggressiveness, confidence and curiosity may affect the prevalence of dog behaviors that are viewed as dominant.

Tuesday, January 12, 2010

Dog Behavior

Dog behavior refers to the collection of behaviors by the domestic dog, Canis lupus familiaris, and is believed to be influenced by genetic, social, situational and environmental causes.

The domestic dog is a subspecies of the gray wolf, and shares many of its behavioral characteristics. Although there are important and distinct differences between dogs and wolves, contemporary views of dog behavior are heavily influenced by research on wild wolves.

The social unit for dogs is the pack. From research on wolf packs that are formed in captivity, the pack has traditionally been thought of as a tightly knit group composed of individuals that have earned a ranking in a linear hierarchy, and in which there is intense loyalty within the group.

It is believed that dogs were able to be domesticated by and succeed in contact with human society because of their social nature. According to this traditional belief, dogs generalize their social instincts to include humans, in essence "joining the pack" of their owner/handler.

However, much of this traditional view is based on findings from grey wolf packs that are formed of unrelated animals in captivity, and thus may not apply to natural wolf packs, natural dog packs, or dogs incorporated into a human household.

Research in packs formed in the wild indicates that wolves form a family group, including a breeding pair and their offspring. In these familial packs, the terms "dominance," and "submission" are less useful than "parent," and "offspring," and bring with them a number of misconceptions.

While the majority of research to date indicates that domestic dogs conform to a hierarchy around an Alpha-Beta-Omega structure, domestic dogs, like their wild wolf counterparts, also interact in complex hierarchical ways.

Dr. David Mech of the University of Minnesota, who has studied wolves in their natural habitat, claims that much of what is widely believed about wolf packs is mistaken. From observations of wolf packs on Ellesmere Island over more than a decade, he claims that natural wolf packs are not at all similar to those formed in captivity by unrelated wolves.

He attributes many of the misconceptions about wolf packs to generalizations from these unnatural packs in captivity, and equates this to erroneous inferences we might draw from generalizing human behavior from studying refugee camps.

Dr. Mech argues that the natural wolf pack is typically a family, with a breeding pair of adult wolves and their offspring. In such cases, the terms "alpha" and "dominant" are less appropriate than "parent." Of course, the parent wolves are both "alpha" and "dominant" (by definition), but he argues that these terms are misleading because they imply that a pack of wolves typically include multiple families and that the members assume a place in a linear hierarchy.

A wolf pack should not be seen as a tribe of individuals who have an established place in a hierarchy until a younger dog usurps the role. Rather, a wolf pack should be seen as a family unit, with young wolves of age dispersing into new territories of their own, to find other wolves and begin their own family units.

Mech also states that dominance is rare in wild wolves, and does not arise from sexual competition. Because young wolves usually disperse before age two, and almost always before age 3, there is little sexual tension within a pack.

Instead of "dominance" and "submission", he uses the terms "assertiveness" and "passiveness" to reflect the role of the wolf in the pack. Dominant breeding pairs led the pack most of the time (71%), and initiated most new behaviors (70%). Leadership behavior in subordinate pack members tended to be followed by dispersion.

Friday, January 1, 2010

Intelligence

The domestic dog has a predisposition to exhibit a social intelligence that is uncommon in the animal world. Dogs are capable of learning in a number of ways, such as through simple reinforcement (e.g. classical or operant conditioning) and by observation.

Dogs go through a series of stages of cognitive development. They are not born with the understanding that objects which are not being actively perceived still remain in existence, called object permanence. This occurs as the infant learns to interact intentionally with objects around it. For dogs, this occurs at roughly 8 weeks of age.

Puppies learn behaviors quickly by following examples set by experienced dogs. This form of intelligence is not peculiar to those tasks dogs have been bred to perform, but can be generalized to myriad abstract problems. For example, Dachshund puppies who watched an experienced dog pull a cart by tugging on an attached piece of ribbon in order to get a reward from inside the cart learned the task fifteen times faster than those who were left to solve the problem on their own.

Dogs can also learn by mimicking human behaviors. In one study, puppies were presented with a box, and shown that when a handler pressed a lever, a ball would roll out of the box. The handler then allowed the puppy to play with the ball, making it an intrinsic reward. The pups were then allowed to interact with the box.

Roughly three-quarters of the puppies subsequently touched the lever, and over half successfully released the ball, compared to only 6 percent in a control group that did not watch the human manipulate the lever. Another study found that handing an object between experimenters who then used the object's name in a sentence successfully taught an observing dog each object's name, allowing the dog to subsequently retrieve the item.

Dogs also demonstrate sophisticated social cognition by associating behavioral cues with abstract meanings. One such class of social cognition involves the understanding that others are conscious agents. Research has shown that dogs are capable of interpreting subtle social cues, and appear to recognize when a human or dog's attention is focused on them.

To test this, researchers devised a task in which a reward was hidden underneath one of two buckets. The experimenter then attempted to communicate with the dog to indicate the location of the reward by using a wide range of signals: tapping the bucket, pointing to the bucket, nodding to the bucket, or simply looking at the bucket.

The results showed that domestic dogs were better than chimpanzees, wolves, and human infants at this task, and even young puppies with limited exposure to humans performed well. Dr. Stanley Coren, an expert on dog psychology, states that these results demonstrated the social cognition of dogs can exceed that of even our closest genetic relatives, and that this capacity is a recent genetic acquisition which distinguishes the dog from its ancestor, the wolf.

Studies have also investigated whether dogs engaged in partnered play change their behavior depending on the attention-state of their partner. Those studies showed that play signals were only sent when the dog was holding the attention of its partner. If the partner was distracted, the dog instead engaged in attention-getting behavior before sending a play signal.

Dr. Coren has also argued that dogs demonstrate a sophisticated theory of mind by engaging in deception, which he supports with a number of anecdotes, including one example where a dog hid a stolen treat by sitting on it until the rightful owner of the treat left the room.

Although this could have been accidental, Coren suggests that the thief understood that the treat's owner would be unable to find the treat if it were out of view. Together, the empirical data and anecdotal evidence points to dogs possessing at least a limited form of theory of mind.

Friday, December 11, 2009

Life Style

The coats of domestic dogs are either "double", made up of a coarse guard hair and a soft down hair, like a wolf, or "single", with the topcoat only. Dogs with double coats tend to originate in colder climates.

Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. A countershaded animal will have dark coloring on its upper surfaces and light coloring below, which reduces its general visibility. Thus many breeds will have an occasional "blaze", stripe, or "star" of white fur on their chest or underside.

There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. In some breeds, the tail is traditionally docked to avoid injuries (especially for hunting dogs). In some breeds, puppies can be born with a short tail or no tail at all. This occurs more frequently in those breeds that are frequently docked and thus have no breed standard regarding the tail.

While all dogs are genetically very similar, natural selection and selective breeding have reinforced certain characteristics in certain populations of dogs, giving rise to dog types and dog breeds.

Dog types are broad categories based on function, genetics, or characteristics Dog breeds are groups of animals that possess a set of inherited characteristics that distinguishes them from other animals within the same species.

Modern dog breeds are non-scientific classifications of dogs kept by modern kennel clubs. Purebred dogs of one breed are genetically distinguishable from purebred dogs of other breeds, but the means by which kennel clubs classify dogs is unsystematic.

Systematic analyses of the dog genome has revealed only four major types of dogs that can be said to be statistically distinct. These include the "old world dogs" (e.g., Malamute and Shar Pei), "Mastiff"-type (e.g., Labrador Retriever), "herding"-type (e.g., St. Bernard), and "all others" (also called "modern"- or "hunting"-type).

Dogs are susceptible to various diseases, ailments, and poisons, some of which can affect humans. To defend against many common diseases, dogs are often vaccinated.
Some breeds of dogs are prone to certain genetic ailments such as elbow or hip dysplasia, blindness, deafness, pulmonic stenosis, cleft palate, and trick knees.

Two serious medical conditions particularly affecting dogs are pyometra, affecting unspayed females of all types and ages, and bloat, which affects the larger breeds or deep-chested dogs. Both of these are acute conditions, and can kill rapidly. Dogs are also susceptible to parasites such as fleas, ticks, and mites, as well as hookworms, tapeworms, roundworms, and heartworms.

Dogs are highly susceptible to theobromine poisoning, typically from ingestion of chocolate. Theobromine is toxic to dogs because although the dog's metabolism is capable of breaking down the chemical, the process is so slow that even small amounts of chocolate can be fatal, especially dark chocolate. Dogs are also vulnerable to some of the same health conditions as humans, including diabetes, dental and heart disease, epilepsy, cancer, hypothyroidism, and arthritis.