It was Yuet the otter's turn for an ultrasound scan. At the call of the trainer, it swiftly climbed onto the examination table without a fuss, stationed itself in the right position - head through the trap, paws on the knobs, nose touching the target in front (see picture right) - and allowed the trainer to scan its belly. The creature's co-operation is down to the training these animals at Ocean Park receive to make them more receptive to a range of procedures designed to keep them in good health, from daily grooming to medical check-ups. 'We won't force animals to do tasks, we co-operate with them,' said the park's Terrestrial Life Sciences senior curator Howard Chuk Hau-ching. 'Training can replace anaesthesia in some medical procedures.' Chuk said imposing care routines on animals can have a negative impact on their health, both physically and mentally, and make it harder for trainers to understand them. He cited the example of a parrot having a blood test. A trained parrot will lie still and spread its wings for the trainer to draw blood. Performing the test on birds who are untrained requires an anaesthetic, and there is a risk the parrot will not wake up afterwards. Only two out of the 80 or so parrots in the park are trained to deal with blood tests, Chuk said. Trained animals have body check-ups on a monthly or even weekly basis, as opposed to those requiring an anaesthetic, which can only be administered once a year. The extra monitoring enables trainers to collect data and build a greater understanding of the animals. The park's red pandas, which arrived last year, are capable of voluntarily allowing trainers to brush their fur and feel their muscles in a simple health check. They can also get on a weighing scale by themselves as part of their daily routine. 'Animals can get hurt when we have to catch them. They may feel pressured when we forcefully perform procedures on them. Some may even lose their appetite. Husbandry training can avoid all these adverse effects,' said Chuk. Zoo operations and education general curator Grant Abel said: 'We focus on developing a relationship of trust between the trainer and the animal, instead of controlling them with food or punishment. We want animals to be involved in the process and enjoy it.' The park began such training with dolphins and sea lions in the early 1990s.