Evolution, Metabolism & Botanical Allies

A look into equine metabolic dysfunction and why Fat Attack makes sense

Over the past two decades, our understanding of equine metabolic health has progressed dramatically. Many stereotypical “fat ponies” or “good doers” are now recognised as having complex metabolic disorders involving insulin dysregulation / hyperinsulinaemia, chronic inflammation and oxidative stress.^{1 2} These horses carry a significantly increased risk of numerous health issues such as excessive weight and mechanical load on the body, altered inflammatory responses, metabolic dysfunction and laminitis, to name a few. While laminitis is usually associated with fat horses, a skinny horse can also become laminitic. This just demonstrates the complex nature of metabolism and why a holistic and scientifically backed approach is currently our best defence.

Laminitis itself is not the focus of this article - but its rising prevalence, the overlapping biological mechanisms that predispose horses to it, a cluster of related health problems, and most importantly, how we approach all of it, is.³ By drawing a clearer line between modern scientific understanding, traditional plant allies and management practices, we can make meaningful shifts and reverse the growing statistics.

Evolution Shapes Biology

Evolution is the architect that forges the life-form, unfolding over millennia through incremental adaptations. In the hoof world, there is a common phrase “form follows function,” meaning the form (shape, structure, and conformation) of the hoof should reflect and support its function (shock absorption, weight-bearing, stability, etc.). This fundamental concept provides the vital framework which can be applied across the entire anatomy and physiology of the horse - however, don’t lose sight that demand is what ultimately determines function. Every system in the horse is “designed” this way and ought to underpin every decision, interaction and expectation we bring to their care. 

Over millions of years, horses evolved as highly mobile, grazing herbivores, adapted to consume high-fibre, low-energy forage almost continuously while travelling long distances in search of food and water. Seasonal fluctuations in forage availability shaped both their metabolism and natural feeding behaviour.^{4 5 6} Think of this as our ground zero, as we unpack how evolution shaped the horse through several distinctive adaptations including:

• Digestive system: Built as a hindgut fermenter to extract energy slowly from fibre, not large, rich meals. Fermentation provides a steady energy source and generates heat as a natural by-product, while near-continuous grazing supports metabolic signalling pathways involved in appetite regulation and energy balance.

• Metabolism: Scaffolded around seasonal feast/famine cycles and continual movement. Calorie-rich diets, stalls and small paddocks can turn these evolutionary advantages into metabolic liabilities.

• Hooves: Engineered for strength, dynamic flexibility and endurance. Chronic hyperinsulinaemia (high insulin in the blood) can weaken the microscopic, velcro-like lamellar bonds that suspend the coffin/pedal bone and maintain hoof integrity.^{7 8} 

• Circulatory system: Evolved for sustained movement, with a powerful heart and specialised hoof circulation that depends on regular movement for optimal perfusion. Chronic hyperinsulinaemia can disrupt this vascular function, compromising hoof health and increasing the risk of laminitis.⁹

• Endocrine system: Calibrated for seasonal feast/famine cycles, with hormones regulating metabolism, appetite, energy storage and adaptive responses to environmental challenges. Rich pasture, energy-dense diets, confinement and chronic stress can overwhelm these finely tuned feedback systems.

  
  

No, we don’t have all the answers, but we do have a remarkably useful guide. By understanding how nature has shaped the horse, we can consider how those adaptations translate to domestic life; in doing so, we gain a priceless anchor on which to base our decisions.

We now understand chronic elevated insulin (hyperinsulinaemia) to be a primary driver of endocrinopathic laminitis, the most common form of laminitis affecting horses today - estimated to account for close to 90% of cases.^{10 11} Once considered primarily a hoof inflammatory disease, research has revealed that metabolic dysfunction, particularly insulin dysregulation, lies at the centre of this modern welfare challenge.^{12 13 14} Importantly, metabolic dysfunction is not a single pathway - PPID / Cushing’s disease can also contribute to insulin dysregulation and laminitis risk through a distinct endocrine mechanism.

While equine metabolism is multifaceted, supporting the body in species-appropriate ways should always be our first and most fundamental step. Considering how interconnected the body, environment and lifestyle are, the following pillars of horse care extend well beyond just metabolic function and sound horses:

• low-sugar/starch, long-stemmed forage-based fibre & nutritionally balanced diet

• exercise/movement. This includes increasing “turnout” movement (track systems are a good example of this, but thoughtful paddock design can go a long way too)

• appropriate environmental factors (pastures, footing, even over-rugging)

• minimal stress (physical or emotional)

• mental stimulation (horse-horse companionship is highly understated)

• commitment to quality hoof, dental & body care

We can certainly mitigate many downsides of domestic life simply by not working against what nature has so exquisitely engineered. While there is no silver bullet that can replace core, species-appropriate management, we can lean into the plant-animal relationships established over millennia. With careful consideration, we can tap into the remarkable array of bioactive compounds and actions in plants that have made them powerful allies in health, throughout that shared evolutionary journey.

Having evolved to be highly selective foragers, horses use smell, taste and post-ingestive feedback to choose from a wide diversity of plants. Despite being well documented in many other species (such as chimpanzees, elephants, parrots, sheep and goats), scientists are yet to conclusively demonstrate true self-medication (zoopharmacognosy) in horses.¹⁵ ¹⁶ The following are just a few examples owners have observed that suggest some level of self-medication may be occurring:

• Laminitic horses often observed seeking Nettles, Hawthorn and Dandelions

• Horses preferentially eating Willow during periods of lameness, injury or illness, possibly reflecting its natural salicin content 

• Older horses or those with itchy skin frequently and voluntarily seeking out Nettle, despite access to ample pasture

• Seasonal observations (particularly Spring) with Hawthorn leaves and flowers and Clivers being favoured, also during times of pasture abundance

  
  

Although there is growing anecdotal evidence, we need to be cautious about assuming the horse instinctively always ‘knows’ what’s best, while also not disregarding the fact that they can at times, appear to display such behaviour. In the meantime, as more studies are undertaken in this area, we can draw upon our own long history with herbal medicine and, with professional advice, make the best-informed decisions on their behalf. Even the plants mentioned above may be contraindicated in certain situations or for individual horses, so a deeper understanding of their actions, interactions and broader implications is essential for their safe use. 

A Multi-Targeted Botanical Strategy

The horse is not a collection of isolated systems - it is an interconnected biological network. Supporting these systems requires a similarly integrated approach. The carefully selected botanicals in Fat Attack are designed to work synergistically, supporting multiple physiological pathways within this biologically complex system, including: 

• Fat metabolism and regional adiposity (eg. ‘cresty’ necks and abnormal fat deposition)

• Adaptogens: Enhance the body’s natural ability to adapt to physical, metabolic and environmental stressors, promoting balanced stress responses, resilience and physiological equilibrium through broad regulatory effects rather than a single targeted action

• Appetite regulation and satiety signalling

• Insulin and leptin sensitivity (supporting healthy metabolic signalling)

• Circulation and peripheral perfusion (supporting delivery of oxygen and nutrients to tissues, including the hoof)

• Hormonal signalling (the body’s communication network, influencing metabolism and whole-body function)

• Inflammatory pathways (supporting a balanced inflammatory response)

• Oxidative stress balance (supporting cellular resilience and protection from excessive oxidative damage)

• Liver and lymphatic function (supporting fat metabolism, waste clearance and immune function)

• Nutrient and oxygen delivery systems (supporting cellular function throughout the body)

There’s no doubt we have shaped the domestic horse in countless and obvious ways, such as colour, size and shape, but beneath those differences, the fundamental biological systems and physiological mechanics shaped by millions of years of evolution remain.

Every system and physiological response we’ve touched on here isn’t a separate problem to solve, nor is the presence of very specific botanical actions just a coincidence - but an elegantly overlapping design responding to life and survival in different ways. That’s precisely why plants belong in any conversation about equine health and why Fat Attack makes sense. 

Horses didn’t evolve in isolation from the botanical world, they evolved within it, alongside it, shaped by the same ancient pressures - a symbiosis stretching back long before either species was recognisable as it is today. Herbal allies aren’t an add-on to biology; they’re part of its history. 

Next time, we’ll open the jar itself and look at exactly how each ingredient in Fat Attack earns its place.

A collaborative piece from the Happy Horse Australia team: 

Nadine Marshall - Equine Naturopath/Herbalist/Nutritionist 

Nathan Marshall - Equine Podiotherapist

Lily Bunton-King - Equine Podiotherapist

References

1. Banse HE, Frank N, Kwong GPS, McFarlane D. Relationship of oxidative stress in skeletal muscle with obesity and obesity-associated hyperinsulinemia in horses. Can J Vet Res. 2015;79(4):329-338. 

2. Frank N, Geor RJ, Bailey SR, Durham AE, Johnson PJ. Equine metabolic syndrome. J Vet Intern Med.2010;24(3):467-475. 

3. Pollard D, Wylie CE, Verheyen KLP, Newton JR. Identification of modifiable factors associated with owner-reported equine laminitis in Britain using a web-based cohort study approach. BMC Vet Res. 2019;15:59. 

4. Harris PA, Ellis AD, Fradinho MJ, et al. Review: Feeding conserved forage to horses: recent advances and recommendations. Animal. 2017;11(6):958-967. 

5. Ellis AD. Biological basis of behaviour in relation to nutrition and feed intake in horses. In: Ellis AD, Longland AC, Coenen M, Miraglia N, eds. The Impact of Nutrition on the Health and Welfare of Horses. EAAP Publication No. 128. Wageningen Academic Publishers; 2010:53-74. 

6. Duncan P. Time-budgets of Camargue horses II. Time-budgets of adult horses and weaned sub-adults. Behaviour. 1980;72(1-2):26-48. 

7. Bowker RM, Van Wulfen KK, Springer SE, Linder KE. Functional anatomy of the cartilage of the distal phalanx and digital cushion in the equine foot and a hemodynamic flow hypothesis of energy dissipation. Am J Vet Res. 1998;59(8):961-968. 

8. Bowker RM. The growth and adaptive capabilities of the hoof wall and sole: functional changes in response to stress. In: Proceedings of the 49th Annual Convention of the American Association of Equine Practitioners. New Orleans; 2003:146-168. 

9. Pollitt CC, Molyneux GS. A scanning electron microscopical study of the dermal microcirculation of the equine foot. Equine Vet J. 1990;22(2):79-87. 

10. Wylie CE, Collins SN, Verheyen KLP, Newton JR. Risk factors for equine laminitis: a systematic review with quality appraisal of published evidence. Vet J. 2012;193(1):58-66. 

11. Durham AE, Frank N, McGowan CM, et al. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med. 2019;33(2):335-349. 

12. Karikoski NP, Horn I, McGowan TW, McGowan CM. The prevalence of endocrinopathic laminitis among horses presented for laminitis at a first-opinion/referral equine hospital. Domest Anim Endocrinol.2011;41(3):111-117. 

13. Asplin KE, Sillence MN, Pollitt CC, McGowan CM. Induction of laminitis by prolonged hyperinsulinaemia in clinically normal ponies. Vet J. 2007;174(3):530-535. 

14. Huffman MA. Current evidence for self-medication in primates: a multidisciplinary perspective. Yearb Phys Anthropol. 1997;40:171-200. 

15. Freymann E, Carvalho S, Garbe LA, et al. Pharmacological and behavioral investigation of putative self-medicative plants in Budongo chimpanzee diets. PLoS One. 2024;19(6):e0305219. 

16. Villalba JJ, Provenza FD. Self-medication and homeostatic behaviour in herbivores: learning about the benefits of nature's pharmacy. Animal. 2007;1(9):1360-1370.