when dog bites us what mechanism is taking place? how we get injure?

Answer 1

The contraction of the muscles of the hinge joint that is his jaw causes his fangs to puncture your skin.

Answer 2

Take Rabies test.

Answer 3

It's called teeth!

Answer 4

Motives to bite
There are many types of aggression among dogs. Classes of aggression include the following (Borchelt, P.L. and Voith, V.L. 1982. "Classification of Animal Behavior Problems," Vet. Clin. North Am. Small Anim. Pract. 12:571-585):

Dominance aggression: aggressive behavior usually directed to family members who take something from the dog, pet it, hold it, pick it up, or disturb it while it is resting.
Defensive or fear aggression: directed to family or strangers who approach too quickly or too closely when the dog is afraid.
Protective/territorial aggression: directed to strangers to approach the owner or the home of the owner.
Predatory aggression: directed to small, quickly moving animals and children, especially where more than one dog is involved.
Pain-elicited aggression: directed to family or strangers who approach or touch when the dog is in pain or injured.
Punishment-elicited aggression: directed to family or strangers who hit, kick or verbally assault the dog.
Redirected aggression: directed to family, strangers and animals who approach or touch the dog when it is aggressive in another context
Factors that determine whether a dog will bite
It unfortunately is common for dogs to direct their aggression against people, by biting them. Two percent of the population of the USA is bitten by dogs every year. (See Statistics. )

There is much in the scientific literature of animal behavior that sheds light on the causes of dog attacks. As you review the literature, it is interesting to note that a dog owner is directly responsible for the presence or absence of most factors that determine whether a dog will bite.

A report by the American Veterinary Medical Association, Task Force on Canine Aggression and Human-Canine Interactions, entitled A Community Approach to Dog Bite Prevention, refers to five factors commonly associated with dog bites:

Breed and "parents" of the attacking dog: this refers to aggression as a type of behavior that has been bred into certain breeds of dogs, and characteristics of the "sire" and "*****" that produce an individual dog.
Socialization of the dog: how the dog has been desensitized to stimuli, especially stimuli produced by children. Poor socialization results in less inhibition to bite and engage in other undesirable behavior.
Training of the dog: the nature, degree and quality of training. A dog that has been trained to threaten people is an obvious danger, but so is a dog that has been poorly trained or not trained at all.
Health of the dog: whether the dog was sick or injured. When a dog is sick or injured, or in pain, biting can result for a number of reasons.
Behavior of the victim: this includes any behavior (i.e., a baby rolling over on a bed), not just provocation (i.e., hitting the dog).
Leaving aside the causes, one must also consider the most repeated scenarios associated with dog maulings. Being in a yard controlled by one or more dogs is a common feature of many of the most recent canine inflicted homicides. Where death is the result, the dog is most often a pit bull or a Rottweiler. It also appears well established that docile dogs often become uncharacteristically violent and vicious in the presence of a pack. The most frequent victims are children and senior citizens.


Examples from studies
Other factors associated with aggression include the following:

Male dogs are more aggressive than females, and most of the aggression is by intact males. Male dogs accounted for 70% - 87% of the attacks studied, and 60% were unneutered males.

Readings in Companion Animal Behavior. Victoria L. Voith & Peter Borchelt. (1996: Trenton: Veterinary Learning Systems) pp. 226, 235
Public Health Reports: The Ethology of the Dog Bite. A. M. Beck, H. Loring, & R. Lockwood. (1975)
A Study of Animal-to-Human Bites by Breed in Palm Beach County, Florida. D. L. Moore. 1987.
Journal of the American Veterinary Medical Association: Selecting Pet Dogs on the Basis of Cluster Analysis of Breed Behavior Profiles and Gender. B. L. Hart & L. A. Hart (1985, Volume 186, pages 1181-5).
Dogs from pet stores and "puppy mills" have a high incidence of dominance-type aggression and defensive or fear aggression.

Early Experience and the Development of Behavior by James Serpell and J. A. Jagoe, in The Domestic Dog, Its Evolution, Behavior, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press).
The Puppy Report. Larry Shook. (1992: Lyons & Burford, publishers).
Inadequate socialization prior to the age of 14 weeks results in a higher incidence of fear aggression.

Science: Critical Periods in the Social Development of Dogs. by D. G. Freedman, J. A. King, & O. Elliot. (1961, volume 122, pages 1016-1017).
Genetics & the Social Behavior of the Dog. J. P. Scott & J. L. Fuller. (1965: Chicago: University of Chicago Press).
Inadequate training and discipline result in dominance aggression.

Effects of Owner Personality and Attitudes on Behavior by Valerie O'Farrell, in The Domestic Dog, Its Evolution, Behavior, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press).
Poor health results in aggression.

Clinical Behavioral Medicine for Small Animals, by Karen Overall (1997: Mosby Year Book, Inc.), p. 2.
See the studies of the Chow, in which approximately 50 genetic diseases have been shown to result in aggression:
Control of Canine Genetic Diseases. George a. Padgett. (1998: Howell Book House) p. 199.
Genetics of the Dog. Malcolm Willis. (1989: Howell Book House).
Behavior Problems in Dogs. William E. Campbell. (1975: Goleta, CA: American Veterinary Publications, Inc.) p. 88.
Dog World: Thyroid Can Alter Behavior by Jean W. Dodd, D.V.M. (October 1992) pps. 40-42.
Pain and fear result in aggression.

Clinical Behavioral Medicine for Small Animals, by Karen Overall (1997: Mosby Year Book, Inc.)
Readings in Companion Animal Behavior. Victoria L. Voith & Peter Borchelt. (1996: Trenton: Veterinary Learning Systems)
Submitting to the first vaccination after the first 8 weeks of life results in greater aggression.

Early Experience and the Development of Behavior by James Serpell and J. A. Jagoe, in The Domestic Dog, Its Evolution, Behaviour, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press), pp. 97 et seq.
Chaining results in aggression (26-28% of dogs involved in fatal attacks were chained at the time).

Journal of the American Veterinary Medical Association: Dog Bite Related Fatalities from 1979 through 1988 by J. Sacks. R. W. Sattin, & S. E. Bonzo. Volume 262, pages 1489-1492.
Chaining or tethering has been declared illegal in many communities. See Current Legislation on Tethering Dogs from www.HelpingAnimals.com, and also Dogs Deserve Better, a website that advocates against chaining and penning dogs. California was the first state in the nation to prohibit chaining (click here to read the law).


Provocation: the myth
In dog bite cases, provocation is a defense. Generally, the provocation defense is often mentioned but rarely supported by the facts.

The provocation doctrine states that a dog bite is justified under certain circumstances, so that neither the dog nor the owner, harborer or keeper of the dog may be held responsible civilly or criminally. The facts that will be deemed to justify a dog bite are similar from jurisdiction to jurisdiction, but they are not always the same. Generally, actions of the person bitten which would have triggered the doctrine of self-defense if the dog were a person are usually considered to be provocation. For example, hitting a dog and causing it to feel pain usually constitutes provocation. The following actions were not considered to be provocation:

Walking toward a dog did not constitute provocation. Chandler v. Vaccaro (1959) 167 Cal.App.2d 786.
Holding packages, walking toward a dog and its owner, and addressing the owner did not constitute contributory negligence. Eigner v. Race (1942) 43 Cal.App.2d 506.
Where the plaintiff was seated in front of the dog, rising up and turning to face the dog did not constitute provocation. Westwater v. Southern Pacific Co. (1940) 38 Cal.App.2d 369.
Reaching toward a dog to pet him did not constitute contributory negligence. Ellsworth v. Elite Dry Cleaners, etc., Inc. (1954) 127 Cal.App.2d 479.
Playing with a dog and patting his head did not constitute assumption of the risk. Smythe v. Schacht (1949) 93 Cal.App.2d 315.
Feeding a dog did not constitute assumption of the risk. Burden v. Globerson (1967) 252 Cal.App.2d 468.
Helping to wrap and transport an injured dog did not constitute assumption of the risk. Davis v. Gaschler (1992) 11 Cal.App.4th 1392. However, in Ohio it will be left to a jury as to whether doing so was sufficiently tormenting as to constitute a defense under a dog bite statute which made "tormenting" an exception to strict liability. Pulley v. Malek, 25 Ohio St.3d 95 (Ohio 1986).
In Burden v. Globerson (1967) 252 Cal.App.2d 468 the court ruled that regardless of the dog's breed, one does not assume the risk of being bitten simply by choosing to initiate interaction with a dog .
In 19 out of 20 cases, the defense is unavailable, having resulted from guessing and speculation.

Under principles of Common Law there is the assumption that dogs are harmless unless they have previously demonstrated a vicious propensity. This often leads to the related assumption that victims of dog attack have provoked or otherwise precipitated the attack. However, those studies which have attempted to document the context in which an attack has occurred generally show that bite victims are rarely engaging in activity that could legally be considered provocation (i.e., causing physical injury to the animal). In the non-fatal bites surveyed by Beck et al. (1975), the victims had no interaction with the dog, or were walking or sitting in 75% of the cases. In 9.6% the victim was playing with the dog and in only 6.5% could the victim's behavior be classified as provocative. (Lockwood, The Ethology and Epidemiology of Canine Aggression, in James Serpell (ed.) The Domestic Dog: Its Evolution, Behavior & Interactions with People, (Cambridge, U.K.: Cambridge



The word "bite" is used in judicial decisions, statutes and local ordinances. Indeed a "bite" is a necessary element for statutory liability in 9 of the 31 jurisdictions that have dog bite statutes. (Footnote 1.) The characterization of the dog's action as a bite or a swipe of the teeth or claws is of paramount importance to dog bite cases which are based upon these dog bite statutes, a dangerous propensity, or ordinance violations that are based upon biting or bite wounds. The precise meaning of "bite," however, differs from one jurisdiction to the next.

Where the word "bite" is not defined by a statute or ordinance where the attack happened, courts throughout the USA hold that the dictionary definition of "bite" shall be used. A typical definition of the verb "bite" is "to seize with the teeth so that they enter, grip or wound." (Webster's Third New International Dictionary (1993) at p. 222.)

For example, in Johnson v. McMahan (1998) 68 Cal.App.4th 173, 176, a man named Johnson was on a ladder, repairing the roof of the McMahans. Suddenly, the McMahans' dog jumped at him. The dog's jaws closed on Johnson's pants. He claimed a part of his leg was also between the jaws, separated by the pants, but the skin was not broken. Johnson fell from the ladder and was injured. The appellate court held that this injury was a bite under the California dog bite statute, which refers to a "bite" but does not define it. The "bite" was the action of the dog in which it closed its mouth upon and gripped the pants of the victim.

In fact, some of the most painful dog bite injuries consist of crush wounds to the soft tissues beneath the skin. For example, a victim wearing denim jeans might have a painful crush injury but no broken skin. It seems only fair that the dog owner be responsible for the infliction of such an injury.

There are some jurisdictions, however, that have passed laws which define a "bite" more restrictively, at least for some purposes. In these jurisdictions, a bite requires a puncture or tear of the skin. For example, consider this city ordinance, which leaves out the concept of a "grip" as being a bite:

Las Vegas Municipal Code, section 7.04.100: Bite. "Bite" means a puncture or tear of the skin inflicted by teeth of an animal.
Note that a city ordinance would control only proceedings governed by city law, such as dangerous dog hearings, as opposed to tort actions brought under state law, such as dog bite claims.



Biting, swiping and clawing
In some cases, it is unclear whether the injury to the victim's skin resulted from biting, swiping with the teeth, or clawing with a paw. Tears and scratches can come from a dog's teeth or claws, and when the teeth are involved, the injury may or may not have occurred as the dog was attempting to close its jaws upon the victim. By swiping or moving its head in a quick manner, a tooth from the dog's open mouth can cause injury. Arguably, such an injury might not be a "bite." Clawing is entirely different than biting unless the manner of attack includes lunging with one or both forelegs raised during an attempted or actual bite.

Characterizing the dog's action as biting, swiping or clawing is often essential to determining whether a defendant is liable for the resulting losses and damages. A bite is an essential element in cases brought under dog bite statutes which specifically use the word "bite." 9 of the 31 jurisdictions that have dog bite statutes make reference to a "bite." (Footnote 1.) The manner in which a dog inflicted injury is also an essential element of the common law cause of action for scienter. In common law cases where the prior act was a bite, liability in the current claim must be based upon a bite or something very close to a bite. Similarly, where liability is based on a dangerous propensity, both the prior and current acts must be substantially similar. Swiping at people with the mouth while playing may or may not be substantially similar to biting. Clawing might be substantially similar to biting if the manner of attack includes lunging with one or both forelegs raised, in which event clawing might well be considered as part and parcel of a certain dog's dangerous propensity to attack.

Three legal issues therefore arise from such incidents. The first issue is which party has the burden of proof that the wound was inflicted by biting, swiping or clawing. "Burden of proof" refers to the obligation to prove that an allegation is true or false.

A party that has the burden of proof must produce sufficient evidence to convince the fact finder that the allegation is true or not. In a dog bite case that is based upon a dog bite statute or ordinance which refers to a bite, or on a dangerous propensity to bite, the victim is required to prove that a bite occured.

The second legal issue that arises is what type of proof is admissible to prove that the action was a bite. Admissible evidence consists of testimony, a document or another item of sufficient relevance and reliability to constitute a fair basis upon which to judge an allegation to be true or false.

There are several methods of proving that the action of a dog was a bite as opposed to something else. First, it is common knowledge that dogs normally close their jaws upon an object as opposed to waving their faces at it, brushing their whiskers against it, or striking it with their snouts. Being a matter of common knowledge, this does not require any evidence at all. The Restatement of Torts 2nd, section 290, establishes that all people are deemed to have knowledge of the "qualities and habits" of animals, including dogs. (Footnote 2.) Therefore the victim would not be required to produce evidence to prove this point, and nevertheless would be permitted to argue it to the fact finder.

The second method of proving that the action was a bite would consist of the absence of witness testimony that the dog's face was going from one side to another or that its claws were raised at the time of the injury. Without such movements, it would appear clear that the intention was to bite and the action in fact was a bite.

Another approach to proving that the action was a bite would be to rule that the existence of a wound, incurred in the immediate presence of a dog, should be presumed as a matter of law to have been inflicted by a bite. This ruling would be based upon the common knowledge that dogs normally close their jaws upon an object, rather than do the things mentioned above. The presumption could be considered rebuttable by evidence that the dog indeed only scratched or clawed the victim.

The third legal issue that arises from incidents in which it is unclear how the injury resulted could be regarded as a political or legislative issue, namely whether the dog bite statutes should eliminate any reference to a bite and focus instead upon the infliction of injury to the victim. The dog bite statutes of most states do not, in fact, require an actual bite. (Footnote 1.) If the policy of the law is to protect people from injuries inflicted by dogs, encourage dog owners and keepers to be vigilant for the safety of others, and spread the burden of canine-inflicted injuries between the victims and the dog owners, there is no reason to limit the statutes to bite wounds.



Statutory liability without physical contact
An interesting issue arises in states where the dog bite statute does not refer to a "bite" and the dog does not even come into contact with the victim. For example, New Hampshire Rev. Stat. Ann. § 466:19 makes dog owners strictly liable for damages caused by a dog's "vicious or mischievous acts." The question is whether this requires that the dog actually come into physical contact at all with the injured person.

The Supreme Court of New Hampshire held N.H. Rev. Stat. Ann. § 466:19 has answered in the negative, ruling that no physical contact is necessary where the dog' actions are mischievous. In the case of Bohan v. Ritzo (1995), a man was riding his bicycle when he saw a small dog running toward him. He stuck his leg out to ward off the dog, lost his balance, and fell, suffering severe injuries. He sued the dog's owners, alleging violation of the statute. A jury awarded plaintiff damages. Affirming, the state high court rejected defendants' argument that a simple encounter with a dog is insufficient to support a claim under the statute. Plaintiff's allegations were sufficient to establish that the dog's actions had been "mischievous," the court said. Moreover, the court noted plaintiff had not relied on the mere presence of the dog, but had alleged specific mischievous actions that caused his injuries.

The court also rejected defendants' argument that the statute requires an actual bite or other direct contact, noting that nothing in the statute's plain language limits its application to those situations. If the legislature had intended to limit strict liability to cases where a dog's vicious or mischievous acts include an actual bite or other physical contact, it could easily have worded the statute to that effect, the court reasoned.



Footnotes
Footnote 1. The states that impose strict liability only where the dog's action is a bite include Arizona, California, Colorado, Indiana, Michigan, Montana, Nebraska, New Jersey and Washington.
The jurisdictions that impose strict liability regardless of whether the action of the dog was a bite or something else include Alabama, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Kentucky, Louisiana, Massachusetts, Minnesota, New Hampshire, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Utah, West Virginia and Wisconsin.
Footnote 2. Restatement of the Law, Second, Torts, § 290 What Actor Is Required to Know: "For the purpose of determining whether the actor should recognize that his conduct involves a risk, he is required to know (a) the qualities and habits of human beings and animals .... "
Illustration (g): "A reasonable man is required to have such knowledge of the habits of animals as is customary in his community. Thus, he should know that certain objects are likely to frighten horses and that frightened horses are likely to run away. He should know that cattle, sheep, and horses are likely to get into all kinds of danger unless guarded by a human being, that bulls and stallions are prone to attack human beings and that even a gentle *****, nursing her pups, is likely to bite if disturbed by strangers."


The first things to do after being bitten
It is important to identify the animal that bit you, because if it is a stray and you cannot identify it, you're facing the possibility of having to submit to treatment for rabies, which can be painful. Also, if you were attacked by a dog or any wild animal being kept by a person, you probably are entitled to receive compensation from the animal's owner, and you might really need that compensation to pay your medical bills, reimburse you for lost income, pay for cosmetic surgery in the future, and help you overcome the pain and suffering from your injuries. (See Legal rights of a dog bite victim.)

After that, get medical attention. You will be in good company, because 1,000 Americans arrive in emergency rooms every day of the year because of dog bites alone! If you are wounded on the face, insist on treatment by a plastic surgeon because emergency room doctors are great at keeping people alive but not necessarily the best at making stitches and wounds look good. After that, be sure to follow the directions of the physician and take all the medications that are prescribed (except for the painkillers, which usually are at your discretion). You might also be ordered to stay out of the sun, use sun block, use scar reduction lotion, change bandages, report for follow up treatment, report for removal of stitches, massage the healing areas, etc. If so, do it!