should i worry about my argentino ?

I am sorry, but why would you have your friend come over and beat the
dog and tease him? It's your responsibility as dog owner to protect your dog
from others and protect others from your dog. People like you shouldn't
have a dog, period!

No i wasn't there when he was beating him !!! he is a stupid guys he thinks he knows about dog training ... i didn't know that he did that !!! i love my dog more than any thing

If your dog is otherwise friendly and well behaved, then your friend hat it coming - the dog was probably just defending himself from being beaten.

Nonetheless, if you love your dog, go to a professional dog trainer and have
your dog trained properly. Big dogs like these need extra effort towards
obedience and command training.

Good luck and enjoy your dog!

please arrange for the dog and yourself to get involved in some training as soon as possible

Of those who are aware of the specifics personality and attributes of this breed, it is the majority opinion that a Dogo Argentino type of breed should not be owned by an inexperienced owner.

You seem to have been aware something wrong was going on before - that the dog hated this guy before this recent attack. This behavior seems pretty irresponsible.

PLEASE read the following info about Dogo Argentino:
http://en.wikipedia.org/wiki/Dogo_Argentino

"Dogos are big-game hunters and are sometimes trained for search and rescue, police assistance, and military work. Due to their physical capabilities, they are not common family pets, though they are sometimes kept by experienced dog handlers."

"... Dogos Argentinos are protective of what they perceive as their territory and will guard it against any intruder. They get along with other dogs as long as they have been properly socialised, but will usually not tolerate another dog trying to assert dominance over them and might not coexist peacefully with another dominant breed of dog."

"The Dogo Argentino was bred primarily from the extinct Cordoba Fighting Dog. It was bred to reduce certain aggressive traits inherent in the Cordoban Fighting Dog, specifically its lack of ability to hunt cooperatively in a pack, as the breed was intended to function as a cooperative pack hunter. In particular areas of the world where dog fighting as a bloodsport remains culturally acceptable, Dogos Argentinos have been used for fighting. Dogos of these lines are extremely aggressive and not suited for big game hunting, unlike the original Dogo Argentino breed .

In the United Kingdom it is illegal to own Dogos Argentinos without specific exemption from a court per the Dangerous Dogs Act 1991, and dogs of the breed may be seized by the police. The maximum fine for illegal possession of a Dogo Argentino is £5,000 and/or up to six months' imprisonment. Breed-specific legislation varies in the United States, with bans on the breed enacted in Aurora, Colorado and New York City. The Australian government has banned the importation of this dog. The dog is also illegal in New Zealand, Norway, Iceland, Portugal, Romania, Singapore, and Ukraine. The ban in the UK has received criticism with a spokesperson from the Royal Society for the Prevention of Cruelty to Animals stating that the law must "focus back on the real problem... the owner."

Clearly you are unaware of how badly you need to have yourself and the dog trained for EVERYONE'S sake who lives near you. DO NOT WAIT.
Depending on what type of activity is going on at the time, this type of dog can be like having a loaded gun. You, the person who was bothering the dog and the dog are all lucky the dog did not permanently maim or kill the person.

so are Tosa Innus and Shiba Innus
and Filia de Brasilianos and Preso Canarios. These are dogs, along with pit bulls that are outlawed in several towns in Washington County Maine as well. All of these dogs need to be handled by someone who understands what ALPHA DOG is all about, and if anybody is even uncomfortqable with that, many opf these breeds will take over and the way dogs dominate is with teeth.

Because of presence of the well-documented other thread about Pit Bulls and the debate over that, I saw no need to bring up the other potential 'problem' big dogs. Of course, there are several big dog breeds which consistantly and disproportionatley show up on police blotters for attacks. Many times, at the root of the problem is often due to some mishandling or poorly trained and/or untrained owners. Sometimes, it's bad luck (e.g. the wrong things happening at the wrong time).

Proper training is a must...as a starting point. That means understanding of what the role of alpha is about and how to make sure it's clearly and consistantly understood by both handler and the pet.

1.) He probably doesn't respect you as an owner, because of the fact that you failed to train him and set boundaries for him. I don't think he would ever attack you, but he'll definitely become more and more disobedient towards you because he doesn't have much respect for you.
2.) when your dog is attacking someone or another animal, don't just yell cut it out. You calmly approach your dog and firmly saying "NO" but try not to yell and be frantic, because that will only further excite the dog.