Equine Obesity and How to Manage Weight

Equine Obesity and How to Manage Weight

Regularly hitting the news is the topic of human obesity, with latest reports showing 63% of UK adults as overweight and obese [7]. More recently however, speculation on weight has extended to our domestic animals, revealing that 1 in 3 of cats and dogs are regarded as obese [18]. Does this suggests our over indulgence and increasingly sedentary lifestyle has transferred to the animals living closest to us? And could this include our four legged friends in the paddock too?

Well unfortunately yes. Several studies within the last decade have estimated equine obesity at 45% on average [4] and ranging from 21% to 73% depending on location, weight classification and horse related factors such as breed [1-3]. This is presumed an outcome of domestic equine management practices such as over-rugging and over-feeding regularly documented in equine news. As this challenges the natural flight animals’ low energy diet and capacity to move for several hours of the day, the horse is now suffering the consequences of living in excess.

The Evolution of Weight Gain

Like us, horses' diets and means of sourcing food have largely diverged from those of their ancestors. Originally walking around 10-30 miles a day to source poor quality forage with low sugar and starch content [16], the horse now has a much less active lifestyle with access to an abundant supply of high quality and energy-rich foods [4,5]. During seasonal body condition changes, their fat stores would naturally deplete prior to the onset of spring as forage became scarcer through the winter. However, modern housing conditions and demands on the horse mean that they are well fed all year round. Unsurprisingly because evolution provided the horse with a metabolism that was suited to their lifestyle, the modern horse is not well equipped to eat rich rations usually given to food-bearing farm animals [5,6], thus resulting in chronic excess adiposity and detriment to the horse’s health [5]. The consequences of these energy dense diets are not dissimilar to those of humans with results such as exercise intolerance and reduced athleticism, thermoregulatory inefficiency, abnormal reproductive performance and the development of lipomas [5]. Not to mention increased predisposition to life debilitating laminitis, hyperlipaemia or osteoarthritis [4]. Although these could solely be triggered by human over-feeding, there are also factors that increase the chances of excess weight accumulating.

Causal Factors

Preliminary analysis revealed that several individual horse and management factors (such as breed, height, ease of weight maintenance, turnout, feeding practices, and exercise regimen can impact obesity [3]. Here are a few risk factors in closer detail.

Age – Young horses tend to be at lower risk of obesity than older horses [6]. This is believed to be a result of the increased energy requirements of young horses as they tend to be more active in the field and utilise more energy for growth and development than older equines. 

Breed—"Draft horses, cobs, Welsh ponies, and other breeds native to the United Kingdom had a higher incidence of obesity compared to Thoroughbreds”. [3] Furthermore, the highest obesity prevalence was seen in shetland ponies at 71.5% [1]. This is because native breeds are generally regarded as hardier and better adapted to survive in harsh conditions. Therefore they probably carry a genotype deemed as ‘thrifty’ and appear to suffer much more than others on a surplus diet [6].

Easy keepers— Horses considered ‘easy-keepers’ or ‘good-doers’ are more likely to possess genetic adaptations like some humans which helps them maintain weight easily and gives them a higher predisposition to gain weight [3].

Use—As with humans, individuals of more athletic status tend to manage weight better. Therefore competition horses had much lower incidence of obesity than leisure horses and those used as companions [2,3]. This is because competition animals are managed in different ways compared to those used for leisure [3]. Especially as they exercise as part of a training programme which is typically more frequent and demanding of the horse’s body. It has been well documented in humans for some time that weight management and overall health can be improved by more exercise and higher fitness levels and is therefore no different for the horse when reducing obesity and insulin resistance [3].

How to manage weight

Firstly, identify whether or not your horse is the correct weight for their height, age and breed. This can be done a number of ways – Body condition scoring or fat scoring, using a weight tape or a weigh bridge. There are often feed companies such as Top Spec that offer weigh days to yards to ensure you receive the most accurate measurement. Find out more here.

Photo by The Horse.com

Once you know where your horse lies, you can implement a weight management plan to achieve and maintain your horse's optimal weight. Here are a few suggestions.

Restricted grazing – To reduce weight, the horse’s intake needs to be restricted and controlled, however cutting out grazing completely can cause equally as much damage. Fortunately there are several options which allow the horse to continue being turned out.

• Strip grazing – Divide your horse’s field into strips so that they have reduced access to grass. Once the grass is of shorter length the horse then has limited intake while strip grazing [11]. It can however reduce your horse’s movement as the nature of a strip is quite small. As recommended by World Horse Welfare, try a U shaped strip with water at one end and the gate at the other to encourage the horse to move [9].

• Track systems – A track system has reduced access to grass but can be beneficial to encourage horses to keep moving while they eat, as they would in the wild. Studies show this can increase the horse's ground coverage by over three times [11]. For more information on track systems, click here.

• All weather turnout – Similarly, if you have the option to turn your horse out on an all weather surface so they can still move around without grazing, this can be a great way to manage weight.

• Turnout times – Avoid turning out during times and conditions when grass fructan (sugar) levels are at their highest. These include early morning, early evening (when its damp), during or just after a frost and any cold spells or instances where the grass is ‘stressed’ [15].

Muzzling – Turning out in a grazing muzzle reduces the bite size the horse/pony can take and has shown to reduce forage consumption by 83% in a 3 hour period [9].

Hard feeding – Ensure hard feed is only given to those in work and in need of extra nutrients. Horse and ponies survive in the wild just fine without it! [9].

Quantity of feed/forage – Make sure you are feeding your horse the correct amount of forage/feed and weight it out! Intake should be around 1.5-2% of their bodyweight [14] and recent research supporting ulcer management shows that 80% of this should be fed during the day (up until 11pm) with the remaining 20% overnight (11pm-7am) [12].

Soaking Hay – Soaking hay for long periods of over 12 hours can reduce non-structural carbohydrate content by up to 50% [13,15].

Rugging – Horses use energy to keep themselves warm by eating. If your horse is overweight, be particularly careful about rugging and over-rugging as this will leave them with excess energy and eventually fat [9].

Activity and Exercise  -The best form of exercise to help your horse to lose weight is a brisk walk or steady trot. Faster work burns carbohydrate rather than fat, so find ways to build walking or trotting into your routine. This doesn’t need to be riding – you can also work your horse in-hand. [9]

Limit treats – Apples and carrot are very high in fructans so try not to be too generous! [10]

Make changes gradually – If you are trying out any new low calorie feeds/balancers or changing the amounts, introduce these slowly. Your horse’s gut is very sensitive and the gut bacteria adapts to feeding practices so quick changes can cause an upset stomach [10].

Finally, prevention is better than cure! 

If your horse falls within one of the categories susceptible to excess weight gain or it has been a problem in the past, don't wait, plan ahead and prevent it!

Even better, have full visibility over your horse's activity in the field, movement throughout the day, heart rate and exercise sessions with a Trackener Life Kit. This enables you to closely monitor factors that may be affecting their weight and even receive alerts when a health problem is suspected! Here are a couple of snapshots of the insights you can receive using the Trackener Life app.

To find out more about all the other amazing features of Trackener Life, head over to our website and social media pages.

And don't hesitate to share with your friends!

Written by Ruth Box BSc, EEBW @ruth_box6910 Email Ruth

References

[1] Williams, J., & O'Connor, C. (2016, May). Prevalence of Obesity in Show Horses. In 6th Alltech-Hartpury Student Conference.

[2] Robin, C. A., Ireland, J. L., Wylie, C. E., Collins, S. N., Verheyen, K. L. P., & Newton, J. R. (2015). Prevalence of and risk factors for equine obesity in Great Britain based on owner‐reported body condition scores. Equine veterinary journal, 47(2), 196-201.

[3] https://thehorse.com/149701/prevalence-and-risk-factors-for-obesity/

[4] Wyse, C. A., McNie, K. A., Tannahil, V. J., Love, S., & Murray, J. K. (2008). Prevalence of obesity in riding horses in Scotland.

[5] Johnson, P. J., Wiedmeyer, C. E., Messer, N. T., & Ganjam, V. K. (2009). Medical implications of obesity in horses—lessons for human obesity. Journal of diabetes science and technology, 3(1), 163-174.

[6] Giles, S. L., Rands, S. A., Nicol, C. J., & Harris, P. A. (2014). Obesity prevalence and associated risk factors in outdoor living domestic horses and ponies. PeerJ, 2, e299.

[7] Obesity Statistics – Parliament UK. Jan 2017. file:///C:/Users/User/Downloads/SN03336.pdf

[8] The Impact of Nutrition and Feeding Practices on Equine Behaviour and Welfare HPB Davidson http://research.vet.upenn.edu/Default.aspx?TabId=3117

[9] How to Manage Your Horse’s Weight http://www.worldhorsewelfare.org/Article/How-to-manage-your-horses-weight

[10] Horse Weight Management https://horseandrider.com/health-and-advice/horse-weight-management-19536

[11] Grazing Systems http://www.inside-out-hoofcare.co.uk/articles/grazing-systems

[12] Hepburn, R. (2011). Gastric ulceration in horses. Pract, 33(3), 116-124.

[13] Longland, A. C., Barfoot, C., & Harris, P. A. (2011). Effects of soaking on the water-soluble carbohydrate and crude protein content of hay. Veterinary Record, 168(23), 618-618.

[14] https://www.msdvetmanual.com/management-and-nutrition/nutrition-horses/nutritional-requirements-of-horses

[15] Watts, K. A. (2004). Forage and pasture management for laminitic horses. Clinical techniques in equine practice, 3(1), 88-95.

[16] Hampson, B. A., de Laat, M. A., Mills, P. C., & Pollitt, C. C. (2010). Distances travelled by feral horses in ‘outback’Australia. Equine Veterinary Journal, 42(s38), 582-586.

[17] Asai Y, Matsui A, Osawa T, et al. Digestible energy expenditure in grazing activity of growing horses. Equine Vet J Suppl 1999;30:490-492. Accessible: http://veterinarynews.dvm360.com/overweight-horses-increasing-problem?id=&pageID=1&sk=&date=
[18] Risk Factors of Obesity: The Human-Animal Bond https://www.slideshare.net/WalthamCPN/risk-factors-of-pet-obesity-the-human-animal-bond