Symptoms, prevention, and treatment for shipping fever in horses

Shipping fever is a lower respiratory ailment that can sometimes affect horses during transportation. It's characterized by the presence of bacteria and other irritants, such as hay particles, dust, or chemicals, in the lower airway. The stress of travel, crowded conditions, prolonged periods of head elevation, and exposure to unfamiliar environments may work against the horse's immune system, rendering them susceptible to this and other conditions. 

Left untreated, shipping fever can progress to pleuropneumonia, a dangerous form of equine pneumonia caused by fluid building up in the lungs and the space between the lungs and chest wall (the pleural cavity). Pleuropneumonia requires hospitalization and may become life-threatening to the animal. 

Between 9 and 12% of all horses transported for distances between 1000-1300 kilometers experience shipping fever, suggesting that infection is at least in part a function of distance of travel. But that doesn't mean that it has to affect your horses! Understanding the symptoms, ways to prevent infection, and treatment options can help you minimize equine shipping fever risks and associated outcomes.

Symptoms

Early detection of shipping fever can help you intervene more quickly, dramatically speeding up recovery and limiting poor outcomes. Symptoms may manifest within a few days of transportation (usually 1-3 days) and can include:

Respiratory changes

Horses affected by shipping fever often develop a persistent cough and demonstrate difficulty breathing. Labored breathing may be accompanied by rapid nostril flaring, which is a sign that indicates respiratory distress. The horse's respiratory rate may also increase, and you may notice that the breaths are more shallow than usual. 

Associated thoracic (chest) pain may inhibit the horse's ability to cough and clear secretions adequately. Horses with shipping fever may also extend their head and neck to positionally support compromised breathing. This posture indicates a need to open the airway and may be a sign of respiratory distress.

Nasal discharge

A thick nasal discharge is a common symptom of shipping fever in horses. Depending on the severity of the infection, this discharge can range in thickness and color from clear to yellow or green.

Fever

An elevated body temperature is a clear indicator of an underlying infection in almost every species. According to the AAEP, a temperature above 101.5° F / 38.6° C is cause for concern for horses. Fever is a systemic response to infection, which can lead to decreased appetite, lethargy, and even confusion. You'll want to frequently monitor your horse for fever and treat it as prescribed by a veterinarian. 

Depression and loss of appetite

Horses affected by shipping fever may display signs of depression, lethargy, and a noticeable decrease in appetite. These changes indicate the horse's overall discomfort. You don't feel good or want to eat when sick, so neither would a horse, right? Your comforting presence and efficient treatment of other symptoms can support the horse and help them feel better faster. 

Prevention

Preventing shipping fever mostly revolves around managing the stressors associated with transportation. If you're concerned about any conditions that could lead to shipping fever or for additional advice on how to prevent the infection, you may consult with your veterinarian. 

Proper ventilation

One of the most effective ways to prevent shipping fever for your horses is to provide adequate ventilation during transport. Improved airflow helps limit the buildup of airborne particles and simultaneously reduces the risk of respiratory infections. One easy way to do this is to open the windows or vents to promote fresh air circulation.

Hydration and nutrition

A well-hydrated and well-nourished horse is far better equipped to handle travel stress and is less susceptible to infections than a dehydrated or under-nourished animal. For this reason and many others, you should prioritize proper hydration and nutrition before, during, and after transportation. 

Gradual acclimatization

Traveling is inherently stressful for horses, since they are usually firmly planted on the ground and free to roam as they please. Familiarizing them with the transport setting may reduce stress and anxiety associated with travel for your horse, minimizing the risk of compromised immune function. It may also help to gradually acclimate your horses to the trailer or transport environment, taking them for progressively longer trips leading up to significant transport. 

Limit travel stress

Minimize travel stress by avoiding overcrowding your horse trailers and providing ample space for each horse to breathe. Plan your route to avoid bumpy roads, and drive smoothly and carefully to prevent unnecessary jostling and sudden movements.

Infection prevention measures

Practice infection control measures to reduce the risk of disease transmission among horses. Avoid contact with horses from unknown or potentially compromised environments, and regularly disinfect trailers and equipment. All horses that travel or are shipped should also be vaccinated against common respiratory viruses, including influenza. Vaccines can help prevent the development of secondary infections like shipping fever. 

Treatment

Addressing shipping fever promptly is an important step to improve your horse's prognosis and prevent the spread of the infection to other animals. This is not meant to be an exhaustive list, and it's worth consulting your veterinarian for additional advice, especially if your horse needs to take medication. 

Isolation

If you suspect shipping fever, you should first isolate the affected horse to prevent the spread of the infection to others. Isolation helps contain the illness and provides plenty of space to deliver comfort and focused treatment to your sick animal. 

Rest and reduced activity

The affected horse should rest and reduce activity to allow its body a chance to recover. Stress reduction also supports the immune system during the healing process, so it will be helpful to keep the animal in a familiar, safe environment where it feels comfortable. 

Anti-inflammatory medications

If your horse is very uncomfortable or has a markedly elevated fever, you may need to administer anti-inflammatory medications as prescribed by a veterinarian. Anti-inflammatories relieve symptoms like fever and respiratory distress. Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed for these symptoms and are very effective at managing pain and reducing inflammation.

Antibiotics

Antibiotics may be necessary when a bacterial infection is present. Your veterinarian will assess your animal and may culture its blood or suspected infection source to determine the appropriate antibiotic treatment based on the specific pathogens involved.

Supportive Care

Offer supportive care, including good nutrition, hydration, and a clean, well-ventilated environment. Supportive measures like these help the horse regain strength and overcome the effects of shipping fever.

Conclusion

Shipping fever is a severe concern for horse owners, requiring frequent assessments, preventive measures, and prompt intervention. Understanding the symptoms and preventive strategies can significantly reduce the risk of your horses suffering from this respiratory condition.