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Nutritional Support for Horses with Lyme Disease

Lyme disease is an increasingly recognized health concern in horses across North America. Caused by the bacterium Borrelia burgdorferi and transmitted by infected ticks, the disease can produce vague symptoms that often overlap with other health conditions. These signs may appear gradually or inconsistently, making diagnosis challenging.

While veterinary treatment is essential, proper nutrition, especially certain nutrients, can help support horses during treatment and recovery by maintaining immune function, muscle health, digestive health, and body condition.

In this article, you’ll learn how Lyme disease affects horses, the common symptoms and treatment options, and how targeted nutrition can help support recovery during and after treatment.

What Is Lyme Disease in Horses and What Causes It?

Lyme disease in horses is an infectious disease caused by the bacterium Borrelia burgdorferi, transmitted through the bite of infected black-legged (deer) ticks. Ticks acquire the bacteria from wildlife such as mice and birds and can later transmit them to horses during prolonged attachment.

The disease occurs across much of North America, particularly in the Northeast, Upper Midwest, and Mid-Atlantic, where tick populations are common. Because tick bites are small and painless, horses may be bitten without owners noticing, making exposure relatively common.

Research from veterinary institutions such as Cornell University and the University of Pennsylvania shows that many horses develop antibodies indicating exposure, although only some develop clinical illness. When disease occurs, the bacteria can affect multiple body systems, including the musculoskeletal and nervous systems.

What Are the Symptoms of Lyme Disease in Horses?

One of the most challenging aspects of Lyme disease in horses is that the symptoms can be vague and inconsistent. Clinical signs may vary widely between horses and may appear gradually over time. These signs often reflect inflammation affecting the muscles, joints, or nervous system.

Common symptoms reported in horses with Lyme disease may include:

  • Intermittent lameness or shifting limb soreness
  • Muscle stiffness
  • Hyperesthesia (extreme skin sensitivity), often accompanied by twitching
  • Irritability
  • Reduced performance or reluctance to work
  • Behavioral changes 
  • Weight loss or difficulty maintaining body condition
  • Lethargy or decreased energy
  • Neurological signs in more advanced cases

Diagnosing Lyme Disease in Horses: Why It’s So Challenging

Lyme disease can be difficult to diagnose in horses because many of its symptoms overlap with other common health conditions and may appear gradually or inconsistently. Horses may show subtle signs that are difficult to attribute to a single cause.

Another complicating factor is that many horses living in tick-endemic regions have antibodies to Borrelia burgdorferi without showing signs of illness. Research shows that a significant percentage of healthy horses in some regions test positive for exposure, meaning a positive blood test alone does not necessarily confirm active disease.

Because of this, veterinarians diagnose Lyme disease by evaluating multiple factors rather than relying on a single test. They consider the horse’s clinical signs, medical history, recent changes in performance or behavior, and the likelihood of tick exposure.

Blood tests are commonly used to detect antibodies against Borrelia burgdorferi, including the Lyme Multiplex Assay developed at Cornell, which measures antibodies to specific outer surface proteins of the bacterium and helps distinguish past exposure from a potential active infection. Other tests, such as ELISA-based screenings, may also be used, and veterinarians may repeat testing over time or evaluate the horse’s response to treatment when determining whether Lyme disease is truly the cause of the horse’s symptoms.

How Is Lyme Disease Treated in Horses: Can Horses Recover from Lyme Disease?

Treatment for Lyme disease in horses typically involves tetracycline-class antibiotics to eliminate Borrelia burgdorferi. Oral doxycycline and minocycline are commonly used because they are well absorbed and effective, while intravenous oxytetracycline may be recommended in more advanced or neurologic cases. Treatment generally lasts several weeks, though recovery times vary, and some horses need additional time to regain body condition and performance.

Because antibiotics can irritate the digestive tract, veterinarians often prescribe ulcer medications and may recommend probiotic supplements to help support gut health during treatment.

In chronic cases or when treatment is delayed, horses may continue to experience muscle soreness, joint stiffness, behavioral changes, or reduced performance. Early diagnosis and appropriate treatment greatly improve the chances of a full recovery.

Nutritional Support for Horses with Lyme Disease

Horses recovering from Lyme disease may benefit from targeted nutritional support to help maintain body condition, support immune and muscle health, manage inflammation, and protect gut health during antibiotic treatment.

While veterinary care addresses the infection, proper nutrition helps support the body during illness and recovery, especially if the horse experiences inflammation, reduced appetite, weight loss, or digestive disturbances.

Supporting Body Condition and Appetite During Lyme Disease Treatment

Some horses with Lyme disease experience reduced appetite or lose body condition during illness or treatment. Systemic infection and certain antibiotics can decrease appetite, also making it harder for horses to maintain weight and meet their nutritional needs. Maintaining adequate caloric intake is important to support recovery and prevent muscle loss, with free-choice, high-quality forage forming the foundation of the diet.

Horses that struggle to maintain weight may benefit from additional palatable, easily digestible calorie sources. High-quality, high-fat and fiber grain concentrates with balanced energy, amino acids, vitamins, and minerals can help support body condition without excessive sugars and starches, also known as non-structural carbohydrates (NSCs).

Offering smaller, more frequent meals, slightly moistening feed or mashes, and incorporating highly palatable ingredients such as alfalfa or forage cubes may encourage intake. 

Immune Support for Horses with Lyme Disease

The immune system plays a central role in supporting recovery from Lyme disease. Proper nutrition helps ensure that horses receive the vitamins, minerals, and antioxidants needed for normal immune function.

Nutrients such as vitamin E, selenium, zinc, and copper contribute to immune health and help protect cells from oxidative stress. These nutrients support the body’s natural defense mechanisms while tissues recover from infection and inflammation.

Muscle Support for Horses Recovering from Lyme Disease

Some horses affected by Lyme disease develop muscle soreness, stiffness, or reduced performance. Maintaining muscle health during recovery requires adequate intake of high-quality protein and essential amino acids.

Key amino acids such as lysine, methionine, and threonine play an important role in muscle maintenance and repair. Vitamin E also supports muscle health by helping protect muscle cells from oxidative damage. Providing balanced protein and essential nutrients can help support muscle recovery as they gradually return to normal training or work.

Supporting a Healthy Inflammatory Response in Horses with Lyme Disease

Inflammation is a natural part of the horse's body’s response to infection. However, prolonged or excessive inflammation can contribute to discomfort and delayed recovery.

Feeding a balanced diet that includes key nutrients can support recovery while the horse heals from infection. Omega-3 fatty acids, antioxidants, and balanced trace minerals help support normal cellular function and a healthy inflammatory response. For example, DHA—an omega-3 fatty acid—has been shown to support inflammatory balance, improve respiratory function, reduce allergic and post-exercise inflammation, and support fertility in stallions.

Gut Support for Horses on Antibiotics for Lyme Disease

Antibiotics are commonly used to treat Lyme disease, but medications such as doxycycline can disrupt the balance of microbes in the horse’s digestive tract. The hindgut contains a large population of beneficial microbes that help break down fiber and support overall digestive health. Supporting gut health during Lyme treatment can help maintain appetite, improve nutrient absorption, and support normal digestive function.

Equine diets built on a foundation of free-choice, high-quality forage, consistent feeding schedules with multiple meals throughout the day, and digestive-support supplements can help maintain gut health during Lyme disease treatment and recovery.

How Tribute Nutrition Supports Horses with Lyme Disease

In addition to veterinary care, thoughtful nutritional management can help support horses recovering from Lyme disease. Tribute Equine Nutrition offers several feeds and supplements designed to help support horses during illness and recovery:

  • Synergize® – A calorie-dense, high-fat, low sugar and starch feed designed for hard-keeping and hard-working horses. This soft, pelleted formula (13% fat, 20% fiber, 15% NSC) helps support body condition, muscle health, and recovery. It provides highly digestible nutrients and includes Constant Comfort® to help maintain healthy gastric pH and Uptake Technology™ to support digestion and nutrient absorption.
  • Senior Sport® – A highly palatable, digestible feed with high fat and fiber and lower NSC levels that helps support muscle maintenance through quality protein and essential amino acids, making it a good option for horses that have lost body condition. This formula also includes Uptake Technology™ to support nutrient absorption and Constant Comfort® to help maintain healthy gastric pH.
  • Essential K® Rebuild – A low sugar and starch ration balancer formulated with chromium and turmeric to support muscle recovery and performance. This nutrient-dense formula provides essential amino acids, vitamins, minerals, antioxidants, and pre- and probiotics to support overall recovery during periods of stress or illness. It can be fed alone or top-dressed on grain concentrates for additional nutrient support during Lyme recovery.
  • Constant Comfort® Plus – A digestive support supplement designed to help maintain stomach and hindgut health. It contains seaweed-derived calcium to support healthy gastric pH, along with aloe vera, glutamine, and lecithin to help soothe and support the stomach lining, plus pre- and probiotics to support hindgut microbial balance during Lyme treatment and recovery. It can also be used alongside the Constant Comfort® Block and Constant Comfort® Paste for additional gut health support.
  • Natural Remedy® and Wholesome Blends® Omega Plus – Omega-3 fatty acid supplements help support a healthy inflammatory response. Because Lyme disease can trigger systemic inflammation, providing omega-3s may help support recovery. Natural Remedy® provides a direct source of DHA to help naturally reduce inflammation, while Wholesome Blends® Omega Plus is an omega-3–rich blend of hemp, canola, and flax oils that supports coat quality, body condition, immune health, and exercise recovery.

Because every horse’s needs are different—especially during Lyme disease recovery—Tribute offers free personalized feeding plans through our team of equine nutritionists. 

References

Article By:
Chris Mortensen, Ph.D.
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