Research in Wales holds out hope that a compound found in 5 per cent of British native plants, including the weed fat hen, could help prevent Equine Metabolic Syndrome (EMS), a key driver in many laminitis cases.
EMS is a body condition that starts with raised blood glucose levels and progresses into insulin resistance, obesity and laminitis.
Dr Carol Michael, from supplement manufacturer Superfix, is investigating whether adding extracts from two indigenous plants into the diet of horses could help reduce the chances of developing EMS, in much the same way that adding plant sterols to the diet can lower cholesterol in humans.
Michael said the two indigenous plants at the centre of the research are actively sought out and eaten by freely grazing horses. One is fat hen, considered a weed in New Zealand pastures.
She said research has shown that the plants compounds in question are able to both prevent and diminish fat deposits whilst at the same time are able to exert an anti-diabetic effect. One of the plant compounds has the ability to prevent glucose reaching the bloodstream from the gut, thus avoiding laminitis from starch overload.
Some animals that have EMS and suffer from laminitis are confined to limited exercise or no exercise at all because of the instability of the laminae, Michael noted.
In these conditions, many owners find strict calorie counting diets difficult and stressful and worry that horses on a diet and stabled for long periods often in solitary conditions suffer a poor quality of life.
Some horses struggle to lose weight particularly in obesity prone animals aptly named good doers who survive on fresh air and this type benefit hugely from the addition of an anti-adipocyte compound to speed up weight loss and help regulate insulin/glucose levels.
EMS was first recognised by veterinarians in 2002 and is considered to be a set of clinical symptoms including obesity, insulin resistance and laminitis.
Michael said: “It would be clearly advantageous if certain beneficial and inexpensive ingredients could be added to the daily diet of affected or at risk animals that were able to assist in the regulation of glucose thus improving health and avoiding the full blown onset of insulin resistance and laminitis.”
Over the past four years a combined European Union-funded research project has been under way looking initially at anti-oxidant content of indigenous plants eaten by horses allowed to graze freely.
Digested plants were then analysed for active plant compounds at the analytical chemistry department at Bangor University in North Wales.
A herd of eight purebred Welsh Mountain Section A ponies have grazed un-hindered over an ancient Iron Age settlement named Caer Carreg Y Fran (Fort of the Ravens).
The hill fort is an officially recognised monument monitored by the Royal Commission and the Welsh-based Cadw. The land has barely changed in hundreds of years and its use by grazing animals has been closely monitored for the last 40 years to preserve the environment.
The 11-acre site contains a wide variety of plants on a mixture of heathland, grass, marsh, ancient woodland and rocky outcrop.
Two of the ponies included in the trial are from families known to suffer from recurrent laminitis, and all of the ponies were bred in the area and are from pedigrees of a pure North Wales line.
The ponies ate a surprisingly predictable and regular rota of plants depending on the season.
At certain times of the year some plants are far more attractive than at other times.
In particular, young silver birch twigs, young holly leaves in late winter-early spring, and wild blueberries in the autumn, each contain a mass of medicinal anti-oxidants.
Historically, gorse, holly and silver birch have been fed to horses as a replacement for hay.
Initially, researchers were looking at anti-oxidant content, but chemical analysis with chromatography revealed the presence of two distinct plant chemicals with anti-diabetic and blood glucose lowering abilities.
One particular plant compound with a long history of research and several patents for its medicinal properties contains three ecdysterone compounds found in 5 per cent of all the wild plants to which the ponies had access.
The most significant amount was found in Chenopodium Album, also known as lambs quarter and fat hen.
This plant was most frequently sought out by laminitis and obesity-prone horses along with another commonly found plant with an iminosugar that prevents glucose reaching the blood stream from the gut.
The sugar and fructan content of grass varies hugely depending on weather and season and particularly high levels in spring and autumn add to the numbers of horses that develop laminitis from starch overload. Michael said it would be of huge benefit to these prone animals to have this highly beneficial and effective compound available during these times of extra stress.
Chenopodium Album is grown as a food crop in India and Africa and was eaten instead of spinach in medieval times. It has been found in the stomachs of Danish bog bodies and storage pits in Iron Age and Roman sites.
Nowadays, it is served as a vegetable in several exclusive London restaurants as it has a less bitter flavour than spinach.
It is known as an invasive weed in America and Europe, and in Britain it is grown alongside sugar beet as a trap crop to the beet leafhopper insect.
Research has shown that the effective level of ecdysterone needed to reduce fat tissue and lower blood glucose is very dose dependent, and at higher levels it is less effective.
As the plant contains high levels of nitrates it is better fed as a stabilised extraction rather than as forage, Michael said.
Phytoecdysteroids are triterpenes that have been shown to reduce fat body mass and have a beneficial effect on glucose levels in the body with an effect similar if not greater than that of Metformin, and antidiabetic drug.
A triterpene is a precursor to a steroid and research has shown that ecdysteroids have anabolic but not androgenic activity and bind to IGF-1 binding sites affecting glucose metabolism.
The ecdysteroids are able to exert a lowering effect on glucose and lipid levels in the blood, thus lessening the damaging effect and delaying the onset of insulin resistance.
“As EMS in its early stages is in fact a body condition defined by raised blood glucose levels in obese ponies it is possible that a more beneficial health state may be attained by the regular addition of ecdysterones to the diet,” Michael said.
“The added benefit is the reduction in the size of the lipids in the adipose tissue and a decrease in the amount of fat laid down on the neck and at the top of the tail.”
In a pilot study of over 100 horses with a body score of greater than three for fat deposits, within two weeks of receiving the additive in the daily feed ration the fat deposit scores had fallen to a score of two or less.
Superfix, along with the Leahurst Veterinary Hospital Equine Obesity Clinic, in Liverpool, are now looking more closely at the way the compound influences the adipose tissue with particular interest in the inhibition of inflammatory markers.
Superfix plans to introduce the both compounds on to the American market this year, initially through a well established and respected farriers group.