Following the sad death of “De Novo News” travel sickness is suddenly very much in the news. So what is the disease and how can you prevent your horse from catching it?
Travel Sickness or Shipping Fever is a bacterial pleuropneumonia which results in damage to the lungs and a build up of fluid in the chest cavity. This disease requires rapid and aggressive therapy often involving prolonged spells in hospital and frequent drainage of fluid from the chest. Even with the best and most prompt treatment at least 10% of horses affected with travel sickness will die and a further 30% will not return to their previous level of athletic performance. This is a very serious disease and young, athletic horses are most at risk from the condition.
The most important factor in the development of travel sickness is – journey length. If the trip is going to be over 7 hours then the likelihood of problems arising increases very significantly. In many cases nothing can be done to shorten the length of time your horse spends on a truck so you must take care to minimise the other risk factors instead. Keep stress and environmental challenge to a minimum – travel is stressful for your horse in any case but it is made worse if the ventilation is poor or there is a poor quality hay on board releasing fungal spores into the atmosphere. Similarly, heat stress and dehydration both have a dramatic effect on stress levels in the horse. If you increase stress then your horse will respond by secreting increased levels of cortisol which in turn will reduce their resistance to infection.
Another crucial factor is head position; horses evolved to spend most of their time with their heads down, grazing. If they are tied for long periods and unable to lower their heads then the fluid which accumulates in the respiratory tract is more likely to pool in the lungs and may trigger pleuropneumonia. If you must undertake a long journey and are unable to stop then at least allow your horse to lower his head frequently and for long enough for fluid to drain from the respiratory tract.
Does pre-travel medication reduce the risk of infection? Many riders treat their horses with both antibiotics and fluids either intravenously or by stomach tube prior to travel but there is scant evidence that this treatment is effective unless the horse is dehydrated or suffering from a pre-existing infection. Similarly immune stimulants have been developed for use in horses but they do not appear to reliably confer an improved resistance to infection during a trip.
The most effective preparation you can make for travel is to make sure that your horse is absolutely healthy before setting out on a long journey. This does not just mean the obvious signs such as a normal temperature, good appetite and no coughing or dirty nose but also blood sampling a day or two prior to the trip. If your horse has an abnormal white cell count or a rise in markers for inflammation such as fibrinogen or Serum Amyloid A (SAA) then the risk of travel sickness is dramatically increased. If this is the case you should avoid travelling the horse if at all possible. If the journey is unavoidable then antibiotics may be justified under these circumstances.
So, if you load your absolutely healthy, relaxed horse onto a spacious truck with good ventilation and plenty of room to get their head to the floor and eat a regular supply of dust free hay, together with free access to clean water then avoid stress from heat or violent movements the chances are that you will arrive at your destination with a healthy horse ready for competition.