Shipping stress is a complex mix of physical, environmental, and psychological pressures. Horses on the road are already off their usual routines and dealing with environmental variables that quickly elevate cortisol levels. The longer or harsher the journey, the greater the toll on the horse’s body and immune system.
Health status plays a big role in how well a horse copes. Those in poor body condition or with weakened immunity are more likely to experience complications. And even otherwise healthy horses can be pushed past their limits without proper prep. One of the most well-documented risks is shipping fever, a respiratory infection caused by lung inflammation and bacterial overgrowth. Horses traveling more than 2 hours (especially in trailers with poor ventilation) are particularly vulnerable. The inability to lower their heads during transport prevents mucus drainage, increasing infection opportunities. According to Kentucky Equine Research, giving horses time to rest and stretch their necks during travel helps reduce this risk.
To mitigate immune stress, avoid sudden changes in diet or routine before travel. Feed, water, hay, and supplements should be continued as usual, with any adjustments made weeks or months in advance. Rapid changes can upset both digestive and immune function.
This is even more important when working with horses that have unknown or incomplete health histories. In such cases, it is wise to consult with a veterinarian and develop a step-by-step plan to gradually reintroduce a feeding schedule, manage vaccinations, and condition the horse for trailering.
When it comes to shipping, thoughtful preparation is essential. Be mindful that immune strength is built over time through intentional support, not last-minute fixes. Here’s a quick list of preparation steps before you hit the road:
Horses in ideal condition are more resistant to heat stress, dehydration, and disease. Those with balanced weight also maintain better hormone and electrolyte levels. Keep in mind that most horses lose some weight during extended travel, so plan to gradually increase feed after the journey to help them recover.
The immune and digestive systems are closely connected. A horse’s gut health plays a major role in its ability to handle physical stress. Feeding plans should be supportive of immune function.
Monitor your horse’s drinking habits leading up to travel. If possible, bring water from home or train the horse to accept flavored water to encourage drinking during transport. Dehydration can escalate quickly while on the road.
Hay from home can help prevent colic and support the gut microbiome during travel. Ideally, feed this hay throughout the trip and for at least a week after arrival.
If your horse is not already comfortable with trailering, begin taking short trips to help build tolerance. Familiarity reduces travel anxiety and physical stress.
Before You Load
Whenever possible, only haul horses that are in good health and calm in temperament. Postpone trips for animals that are ill or recovering from illness or injury. Make sure they’ve had ample forage and water ahead of time, as stress during transport can reduce appetite and drinking.
Keep vaccinations up to date, planning them far enough in advance—about two to three weeks before departure—so the horse’s immune system has time to respond fully.
On the Road
Maintain steady airflow in the trailer to prevent excess heat, dust, and humidity from building up.
Plan regular breaks, roughly every few hours, to allow horses to stand quietly with their heads lowered, helping clear the airways and support healthy breathing. Use these pauses to check their condition and comfort.
After You Get to Your Destination
Give horses the chance to move freely—turnout or a hand walk can help them loosen stiff muscles and relax. In the days following the trip, watch closely for any signs of trouble, such as elevated temperature, nasal discharge, or cough, which may indicate respiratory problems or other health concerns.
Incorporating targeted immune-supportive nutrients and botanicals into your horse’s diet well before travel can help build internal resilience.
Key nutrients that support immune health include Vitamin C to protect cells from oxidative stress, folic acid for immune cell production, and zinc for additional immunity and tissue repair.
Botanicals are also known to be helpful for supporting the horse’s immune system. Some equine-friendly options are goldenseal, echinacea, yellow dock, schizandra berry, and ashwagandha.
These natural ingredients can assist in maintaining immune balance during stressful periods like travel. Always consult your vet before starting any new supplement and begin any regimen at least a few weeks before departure to allow the horse’s system to adjust.
