Dehydration and increased risk of respiratory problems are common outcomes of transport, and both appear to be related to journey duration, emotional effects, such as fear, and challenging environmental conditions. Welfare may be improved by familiarising equines with transport vehicles and loading procedures before travel starts, and by providing thermally comfortable and well ventilated conditions during the journey. For long road journeys, rest breaks with drinking water should be given. Both trained and unhandled animals should have sufficient space and freedom to adjust their posture and to lower their heads, but maximum safe space allowances are unknown. Mares and foals should be transported together. Injury during transport is relatively common, particularly in groups of horses travelling to slaughter, and is usually associated with driver error, internal fittings and vehicle type or design, but also with mixing of animals of different sex and weight leading to fighting. There needs to be better training and monitoring to prevent such avoidable risks to horse welfare. There is also a need for more research into appropriate prophylaxis and post transport therapy as knowledge of accumulated stress and depressed immune function following prolonged and repeated transport is poorly understood.