About Equine Challenge Supplements
Helping Horses Thrive Through Science-Based Equine Nutrition
For more than 20 years, Equine Challenge Supplements has helped horse owners across the United States and Canada improve hoof health, digestive health, metabolic balance, muscle development, and overall wellness through doctor-formulated horse supplements.
Founded by Dr. Mackie Hartwig and Kathy Hartwig. Continued today by Kathy Hartwig, our mission remains simple:
Help every horse thrive—not just survive.
Our Story
Dr. Hartwig made his home in Clovis, California, with his wife Kathy and their beloved Morgan horses. Together, they provided nutritional counseling, equine supplements, rehabilitation, barefoot hoof trimming, and horse training. Always guided by their deep commitment to the well-being of every horse they helped.
With Mackie’s extensive background in science, he had years of experience in nutrition, focusing on the synergy of ingredients to achieve optimal results. When he and his wife Kathy started their Morgan farm in 2005, Mackie discovered a lack of available quality nutritional options. That is when he went to work in creating Equine Challenge Supplements.
From its inception, Equine Challenge Supplements quickly became a trusted name in equine nutrition, offering a complete line of forage-specific, doctor-formulated supplements designed to meet the individual needs of horses across the United States.
Together, Dr. Mackie Hartwig and his wife Kathy provided nutritional counseling, equine supplements, rehabilitation, barefoot hoof trimming, and horse training.
Following Mackie’s passing in 2013, Kathy has carried forward their shared dream and mission. Kathy continues to provide horse owners and trainers across the United States and Canada with the highest quality, bioavailable equine nutritional supplements available.
At Equine Challenge, our purpose remains unchanged: to help every horse not just live, but truly thrive.
Why Horse Owners Choose Equine Challenge Supplements
✔ Doctor Formulated
✔ Forage-Specific Nutrition
✔ Highly Bioavailable Minerals
✔ Human Grade Ingredients
✔ No Soy
✔ No Added Iron
✔ Chelated Trace Minerals
✔ 7-Strain Probiotic Package
✔ Flaxseed Base Rich in Omega-3s
✔ Free Shipping
What Makes Our Horse Supplements Different?
Unlike many horse supplements that use inexpensive fillers or generic ingredients, Equine Challenge Supplements are formulated using highly bioavailable vitamins, chelated trace minerals, stabilized flaxseed, amino acid complexes, and forage-specific balancing to help horses get more from every serving.
- Hoof supplements
- Digestive supplements
- Vitamin & mineral supplements
- Joint supplements
- Muscle support
- Metabolic support
Our Philosophy: Feed the Horse, Not the Marketing
- Forage first
- Balancing deficiencies
- Not just throwing supplements together
- Avoiding unnecessary ingredients
- Quality over flashy marketing
Our Commitment to Horse Health
At Equine Challenge Supplements, we believe in proactive nutrition designed to help horses thrive, not just survive. True horse health begins with providing the nutritional foundation needed to support a strong immune system, healthy metabolism, digestive function, and overall wellness before problems arise.
From supporting rescued horses and horses recovering from nutritional challenges to maintaining the health of senior horses and equine athletes, our goal is the same: provide high-quality, science-based equine nutrition that helps horses reach their full potential.
Forage Specific Horse Supplements
We believe forage specificity is the foundation of proper horse nutrition. Every horse’s nutritional needs begin with understanding the forage they consume, not waiting until deficiencies or health concerns develop. That is why Equine Challenge Supplements are doctor formulated to provide the essential building blocks horses need for everyday health while offering the flexibility to meet the demands of horses at every level of activity.
Our forage-specific vitamin and mineral supplements are carefully balanced to complement the forage you feed, whether it is alfalfa, grass hay, oat hay, or a combination of forage sources. Each formula is delivered in a food-grade stabilized flaxseed base and includes highly bioavailable vitamins, minerals, trace minerals, and a 7-strain digestive probiotic package.
Easy To Feed
Equine Challenge Supplements can be easily mixed with grain, hay pellets, or fed alone right from the bucket. Our formulations are designed to support overall wellness, including metabolic health, immune function, digestive health, healthy hoof growth, and skin and coat condition.
A little about our flaxseed based supplements. Unlike many processed flaxseed products, our flaxseed base is produced using a high-speed micronizing technique that slices the flaxseed rather than crushing it. This process helps avoid rupturing the fat cells at higher temperatures, creating a stable, nutrient-rich product with a shelf life of six months or longer when properly stored.
Equine Nutrition
Equine Challenge offers a complete line of horse supplements formulated to support a variety of nutritional needs, including hoof health, joint support, tendon and ligament support, digestive health, topline and muscle development, fly control, calming support, herbal support, and more.
Explore our complete line of forage-specific horse supplements and discover how Equine Challenge can help support your horse’s health from the inside out.
Meet Kathy Hartwig
Kathy spent many years working at Conejo Valley Veterinary Clinic in Thousand Oaks, California before moving to the Central Valley. As the owner of Equine Challenge Supplements, Kathy Hartwig is honored to continue the work and vision established by her late husband, Dr. Mackie Hartwig. Every day, she works directly with horse owners to answer questions, provide nutritional guidance, and help develop forage-specific supplement programs tailored to each horse’s individual needs. Kathy believes that educating horse owners is just as important as providing high-quality supplements, which is why Equine Challenge is committed to offering practical, science-based information alongside doctor-formulated products. Whether helping a customer support hoof health, digestive function, metabolic balance, or overall wellness, Kathy is dedicated to treating every customer with honesty, respect, and the same personal care that has been the foundation of Equine Challenge Supplements for more than two decades.
Learn More About Horse Nutrition
Our commitment to education is why we continue to publish resources on topics such as hoof health, digestive health, insulin resistance, vitamin and mineral nutrition, and forage-based feeding.
Visit our Education Center for expert articles covering:
Trusted By Horse Owners Across North America
