THE best greyhound ever to grace the Macau Canidrome is being given a final chance for glory in the one race that has eluded him - the prized Carlsberg Derby. The dog is Mr Boo who is the darling of the regulars who flock to Asia's only dog track and he created a new record recently when chalking up his 41st career win. That took Mr Boo's earnings to well over $200,000 which is a handy return on a dog that cost $15,000 after he came to Macau in January, 1991. Now nearly five-years-old, Mr Boo has captured in his time the STDM Cup, the Directors' Cup, the Carlsberg Green Trophy and the Ballantines Trophy. And to show that, although he is getting a bit long in the tooth, he is still very much a top dog, he haswon eight of his last 14 starts. His 41 career wins is a Canidrome record unlikely to be equalled as racing gets more and more competitive. Track manager Brian Murphy, who handled Mr Boo in his early Canidrome days, said yesterday: ''He is a superb dog, all heart and totally competitive. ''I was speaking to his owners recently and Mr Boo will definitely get his final chance at the Derby. ''It won't be easy for him but really the way he has been racing recently suggests he still has a hope. But this would be his last chance as he would then be rising six and that is just too old.'' Apart from 41 wins, Mr Boo has also placed 18 times and broken three track records. He still holds the Canidrome's 595-yard record. Meanwhile, there is another of the track's popular auctions tonight where nine lightly raced and well performed dogs go up on the block. The auctions have developed a following of their own and very rarely do dogs not meet the reserve price. Four of the better performed dogs tonight have an upset price of $15,000. And in case you are wondering what fish and chips have to do with greyhound racing, the man to query is Bob Teasdale, supremo of the vastly popular Harry Ramsden's fish restaurant in Wan Chai. The restaurant is the latest sponsor for a special race on Scottish night at the Canidrome in mid-June.