How to support your horse’s immune system

A strong immune system protects your horse against a host of outside invaders, including bacteria, viruses, and parasites. A properly functioning immune system is critical to your horse’s well-being.

There are three types of immunity. All three are important.

Natural Immunity: acquired over time as the horse is exposed to various pathogens.

Artificial immunity: induced by vaccines.

Passive immunity: short-term immunity passed to a foal from his or her dam.

The immune system in action, the role of the innate system, and the adaptive immune response:

Think of the innate immune response as the first responders of the immune system. The innate system is present at birth; it reacts to any intruder and has no memory. Its role is to slow the destruction caused by the invading pathogen until the specialists in the adaptive response can take over. The adaptive is different from the innate response because it is targeted, learned, and has memory.

The first responders spring into action:

Pathogens invade the body when they breach the horse’s first line of defense: the skin and/or mucus membranes. These damaged epithelial tissues sound the 911 alarm by releasing messengers called cytokines and chemokines. The first role of the messenger is to cause inflammation (heat and swelling), which alerts the innate immune system’s first responders, known as phagocytes, to spring into action. The messengers also cause vasodilation (opening up of the blood vessels), which allows the responders to gain access to the point of invasion.

Three types of phagocytes arrive at the scene to help.

Neutrophils arrive first. They are abundant in the blood and are always on high alert. The neutrophils attack and attack hard, binding to the pathogens and killing them off. However, neutrophils are short-lived, and as they die off they produce one of the first indicators of infection, pus.

Monocytes arrive at the scene soon after the neutrophils, but they live longer, and have the ability to circulate out of the blood and into other tissues where they continue to scavenge for and kill invaders. When working within the tissues, they are known as macrophages.

While the neutrophils and monocytes are holding off the invaders, the dendrite cells are calling in the specialists. Dendrite cells capture an invader and break it down into antigens, which they then transport to the lymph nodes via the body’s superhighway, the lymphatic system.

The adaptive immune system brings specialized weapons to fight.

Once the messengers reach the lymph nodes, the lymphocytes (white blood cells, T-cells and B-cells) examine the antigen to see if they recognize it and have a defense ready in their memory banks. If they know which antibodies will neutralize the foe, they send them quickly to the site of the invasion. If the invader is new, it takes the system longer to react.

The adaptive immune system is “learned”; in other words, the cells need previous exposure to an invader in order to develop a defense. The weapons used to defeat a known enemy are stored in memory T-cells and B-cells that wait in the lymph nodes. If the invader is recognizable, the T-cells, T-cell helpers, and B-cells flock to the scene of the invasion and help neutralize the enemy.

When the adaptive immune system meets an unknown invader, it takes longer for it to create the biological weapons needed to win the war against the invader.

Things return to normal.

Once the infection or pathogen is defeated and the memory T- and B-cells head back to the lymph nodes to wait for the next emergency, the clean-up crew starts working on rebuilding damaged tissues.

What can compromise your horse’s immune system?

• Mental and/or physical stress plays havoc on the immune system. Stress stimulates the horse’s body to produce stress hormones. These stress hormones suppress the immune system and weaken its defenses. Long-term stress can be very detrimental.
• Trailering and shipping, even for short distances, have been shown to have a negative impact on a horse’s immune system.
• Malnourishment and nutrient deficiencies can reduce immune cell production, weakening the army that defends the body. Minerals and vitamins play an important part in immune health.
• The digestive tract in the horse plays a huge role in immune strength. If the digestive tract is compromised, the immune systems suffers.
• Age also plays a factor. The very young, immature immune system and the older, diminished immune system increase a horse’s risk of getting sick.
• Although rare, certain immune diseases can also leave a horse vulnerable to disease and infection.

How can you support your horse’s immune system?

Good management and nutrition are key in maintaining a strong immune system. Horses are social animals that thrive on routine. Practicing good management goes a long way towards reducing everyday stress in our horse’s lives.

3 good management practices that reduce stress:

1) Set up a daily schedule and stick to it as often as possible to reduce anxiety.

• Feed on time.
• Turn out and bring horses up within the same window of time.
• Allow horses time to rest and nap in a quiet environment.
• Set up a routine around riding. Include plenty of time for grooming, and warming up your horse.
• Make changes slowly so horses have time to adapt.

2) Create social groupings (herds) of horses and provide safe turnout.

• Group horses based on age, sex, and personality. Look for harmonious groupings where everyone gets along. A social group can contain as few as two or three horses. Research has shown that some daily physical interaction with a “friend” is important to a horse’s mental well-being and reduces stress.
• Keep horses where they can see each other, even when restricted to stalls. Isolation causes a great deal of stress in a horse.
• Protect timid horses from being bullied, particularly during feed time.
• Resist constantly moving horses in and out of established groups. Each time a new horse is added to a group, the herd’s pecking order is reshuffled. This can be very stressful and is often accompanied by injuries within the herd. If you have to introduce a new horse, do so slowly.

3) Provide good nutrition.

• Feed good quality hay and lots of it. Horses should consume 1.5% to 2% of their body weight in hay daily. It is best if they have access to forage 24/7. For easy keepers, use slow-feed nets and feeders to increase the time it takes to consume forages.
• Use concentrates to provide the additional energy needed to fuel performance, reproduction, and the maintenance of healthy body condition. Choose a feed developed to meet your horse’s specific needs based on age, metabolic status, and workload.
• Include supplements as needed to fill in the nutritional gaps in your horse’s diet. Nutrient needs vary based on age, workload, type of work and health status.  Pick targeted supplements that provide effective levels of the desired nutrients.

Recommended Supplements

Elevate® natural vitamin E

Vitamin E is a powerful antioxidant that is research-proven to support a robust immune system. Antioxidants are needed to counter oxidative stress at the cellular level. The more a horse trains, competes and travels, the more oxidative stress they are exposed too. Illness and injury also increase oxidative stress. The best source of vitamin E in the diet is fresh green grass. Horses on limited turnout, in hard training, or those restricted from grazing do not consume enough natural vitamin E in their diets and should be supplemented.

Contribute™ omega 3 fatty acids

Omega-3 fatty acids are used in the synthesis of hormone-like substances called prostaglandins. The primary function of these prostaglandins is the regulation of essential body functions such as blood clotting, blood pressure, and immune and inflammatory response. Prostaglandins produced from the omega-3 series tend to mitigate the inflammatory response and support a healthy immune system.

Neigh-Lox® Advanced digestive support

Neigh-Lox Advanced provides a scientifically advanced blend of ingredients that work synergistically to maintain a healthy stomach, small intestine, and hindgut. Horses with a healthy GI tract absorb optimal levels of nutrients. They have a healthy immune system and are less prone to digestive health issues.

Micro-Phase™ vitamins and minerals

Horses consuming an all-forage diet or those that don’t eat the recommended amount of a fortified concentrate may be missing important vitamins and minerals from their diet. Micro-Phase fills the nutritional gaps, so horses have the nutrients they need to maintain a robust immune system.

Trouble Free™ calming paste and powder
Some horses are just more anxious than others. Anxiety causes the release of stress hormones that can weaken a horse’s immune system over time. Trouble Free provides targeted nutrients that help reduce anxiety when a horse is in a stressful situation. Trouble Free can be used as need in specific situations or it can be fed daily.