For example, studies can involve:

• non-invasive behavioural observations of conscious animals; non-invasive methods such as ultrasound scanning or X-ray examinations or other sophisticated imaging techniques in conscious animals;
• non-invasive methods such as external collection of urine and faeces;
• limiting the invasiveness by taking blood samples using a needle the minimum number of times required to achieve the desired goals;
• a hormone implant is placed under the skin using local anaesthesia instead of, for example, surgically modifying the animal to change the way it produces the hormone;
• the animals are kept unconscious with a general anaesthetic throughout the study at the end of which they are killed with an overdose of that anaesthetic – unconscious and dead animals cannot suffer or experience pain;
• anaesthetics, pain-killers (analgesics), sedatives and/or tranquillisers are used to relieve anxiety, fear, pain or distress in conscious animals;
• any surgery on the animals is done by expert surgeons and great care is taken to keep damage to body tissues to an absolute minimum, thereby reducing any pain experienced when the anaesthetic used during the surgery wears off;
• when the animals are likely to experience pain, suffering or other harm (e.g., in studies of diseases), their condition is assessed very regularly, the earliest signs that the study objectives have been met are identified, and the animals are withdrawn from the study or euthanased at that earliest time.

Also animals are handled gently throughout and, where possible, are given extra attention, including food treats and stroking, to enhance their well-being