The 44-year-old Portuguese soccer boss was held late yesterday after an animal health official and two police officers went to his central London home to remove his dog, the Sun newspaper reported.
The paper said the official wanted to put the dog into quarantine, believing it had been taken out of Britain and then brought back without the necessary inoculations.
It said Mourinho refused to let the official take the dog and was arrested at around 10 pm local time after arguing with police.
The Sun said Mourinho had been at Chelsea's player of the year awards and rushed home when he was called by his wife Tami.
Mourinho made a reference to yesterday's events and issued a plea for British media to leave his family alone during a news conference to discuss Saturday's FA Cup final between Chelsea and champions Manchester United.
Asked if it hurt him to hear commentators saying United had played the better football this season, Mourinho said: ''Since what happened yesterday to my family nothing hurts me...It is impossible to compare my family with football.'' Speaking at the club's Cobham training ground, south of London, he added: ''What hurts me was what happened yesterday to my family.
''If I have to say something more about it, it's please contact your colleagues and tell them to leave my kids alone.
''Because to go to school followed by 10 (TV) cameras, 20 photographers and 20 more people behind, I don't think is a nice situation for the kids.'' Despite the visit on Tuesday, police left without recovering the dog, which the Sun said was now on the loose.
A Scotland Yard spokesman said: ''A 44-year-old man was arrested on suspicion of obstructing police. He subsequently received a caution for obstructing police.'' He said an officer from the Animal Health and Welfare Service had gone with police officers to seize the dog because of alleged offences under the 1981 Animal Health Act and the 1974 Rabies Order.
He confirmed the animal had not been recovered.
REUTERS DH KN2127