I'm a new dog trainner here in Brazil,I haven't experience but I'm studding a lot and I have some courses like a basic obdience,KNPV.. . I would like to obtain informations and helps because I've some doubts,example:
How to approch of agressive dog first time ,first contact?
thanks everybody that help me,and sorry about my poor english!

Luciano.

Hi Luciano,

I've been specializing in training over-aggressive dogs for about 10 years.
The first thing you will need to know is why the dog is acting aggressively. All situations are different. Is the dog fearful, dominant, or combination of both? Is the dog protective of its owner, territorial, etc. What will trigger the aggression?
Second, understand dog body language and your own. For example, don't take your eyes off a fearful/dominant dog when it is loose because it may sneak bite you. But, too much eye contact may trigger a bite from a dominant dog without much fear. A very fearful dog who is growling but has a tucked tail will do best with a very non-threatening posture and no eye contact with soft voice.
Despite all this it is always best to take safety considerations first. Almost any dog if muzzled first by the owner can be safely handed over to a trainer. Spend a day with the dog in a basket muzzle and leash. Take the dog for a walk to a new place or sit at the computer with the dog tied to you while you're on the computer. Don't try to pet a dog until it is obvious it feels comfortable with you. Give treats through the muzzle and show your confidence and dominance by simple leadership excercises by taking the lead on the walks.
No matter what type of aggression you encounter always be HAPPY and CONFIDENT even when taking a non threatening posture.
Another trick for certain situations where a muzzle isn't available is for the owner to attach two leads. Then, hand one over to you. Walk the dog together until the dog feels comfortable with you then the owner detaches his/her leash. If the dog comes at you before the leash is detached the owner can restrain with his/her leash. You can even test how the dog will respond to your commands while two leashes are attached. This is called double handling.
If an aggressive dog is in your possession with no owner it is best to start with no corrective training until you gain the dogs trust and dominance passively. For example, the dog will recieve 100% of its food from your hands. When the dog trusts you it will have to do a command before it gets the food. There is much more to passive dominance training but that's just an example.
I hope this is enough random information to give you at least a couple of tips for your tool belt.
Good luck with your new career.