A German businessman who trained his dog to perform a Nazi salute was today sentenced to 13 months' probation for violating laws banning neo-Nazi activities.

Judge Wilhelm Brand told Roland Thein, 54, a rightwing fanatic: "You are very close to going to jail for a very long time. I don't want to hear of you again, not another provocative word."

Thein, who runs a prosperous truck dealership and a wine import business, responded by taking out a comb and brushing his hair to resemble Hitler's distinctive fringe. He was already sporting a toothbrush moustache.

"You are trying my patience," said the judge.

The judge had earlier ordered Thein to remove a T-shirt depicting a baby with Hitler's head superimposed. Officials also confiscated a picture of the German flag with his dog at its centre.

The charges against Thein included the wearing of a shirt with banned Nazi symbols, including the swastika; the taunting of foreign schoolchildren; the shouting of Nazi slogans in the middle of a Turkish market in Berlin and insulting a policeman.

These incidents were only the tip of the iceberg, according to witnesses.

Thein, accompanied by his dog, Adolf, criss-crossed Berlin looking for people to provoke, the court was told.

The dog, which lives in a fortified kennel marked with his name, was an essential prop. For years, it has allowed Thein to shout out Nazi slogans while pretending to bark orders.

When he spotted a foreigner coming in his direction, Herr Thein shouts: "Sieg Heil! Adolf - sit! Give the salute!" The dog - an Alsatian vaguely resembling Hitler's favourite dog, Blondie - obeys.

German lawyers have been unsure as to whether yelling Nazi catch phrases at a dog constitutes an offence. As a result, Thein has escaped serious punishment, getting away with a £100 fine and probation.

Thein could have been imprisoned for three years. German authorities started to take a tougher line with him when he and his dog started to become minor celebrities featured in the tabloid press.

Japanese tourists have come to visit the dog and police have become used to frog marching Thein and his faithful companion out of public meetings after loud homophobic tirades against Klaus Wowereit, the mayor of Berlin.

Thein was unrepentant, telling the court that the only good judge there had ever been in Germany was Roland Friesler, Hitler's hanging judge.

The leniency shown to the businessman is largely because he is not linked to any recognised neo-Nazi group. "He is simply a very offensive eccentric loner," said a court official.

Thein said: "I am a German. I was born in Bavaria, the son of a cavalry officer, and I grew up this way – I don't know any other way."

"Adolf is a very sweet dog," said Nicole Bumann-Zarske, the man's lawyer. "He loves biscuits, just like his owner!"

A friend of the man, who declined to give his name, said that the dog had been hit by a car, damaging his right paw. "It's all bent, he can't stick it out anymore.”