hi well i have a 3 year old kelpie who has bitten(not big chunks off has broken the skin slightly though) both my sister and my cousin these are the only times in 3 years and the incidents had over a years interval in between how bad is this and how do i teach it not to

Unless your dog is biting a robber or someone being violent to them or another person, biting is usually not a good thing - especially if they have broken skin. But dogs bite for different reasons. It could be because the dog is being agressive or defensive. It could be because he's resource guarding. It could be because he wants to play and doesn't realize that he's hurt someone. It could be because he's simply trying to get your attention and doesn't mean to hurt anyone. There are many reasons.

It doesn't seem like your dog has a chronic issue, but it is very possible that he may bite again. In order to get your dog not to bite, you have to figure out the reason why he's biting first. Then, depending on what is causing the situation, you can prevent it from happening again.

Dogs are biters - it's a natural thing for them to do whether it's to hunt, protect or play. Therefore, there is no "cure" for a dog not to bite, but there are ways for us to work with our dogs to keep them in check and control the urge.

Just like Grace said biting is a dog natural instinct....
Just like barking...
Maybe train your dog better to have a proper behavior...
Find out the reason why your dog tend to bite like that...
So that you can prevent it...("

If you suspect that your dog is biting because it is uncomfortable when people are near him please visit this site

Working with a fearful, scared or shy dog

You need to work with this dog as the behavior is not likely to improve otherwise. A scared dog that has moved to biting to keep people away has found a very effective behavior to get what it wants (to be left alone). The dog should not be punished for this behavior (remember if it's afraid punishing the dog is not going to do anything to stop the fear). Punishment for this kind of biting rarely has long term success and is not reliable. You need to change how the dog feels about having people come near it. This takes time, training, patience and commitment. The dog should be monitored and not allowed near people, do not let people lure the dog near them with food as this could also result in a bite. You should find a trainer to help you out, especially if you're not sure why the dog is biting. The website above has a link to certified trainers around the country.