Grazing Muzzles - Love them or hate them ?

Grazing Muzzles. Love them or hate them they are frequently used as part of weight management regimes. So are they doing what we hope they are doing and how do they affect the ponies and horses that wear them?
Equine obesity is linked to an increased risk of laminitis, in a country of rich green lush grass keeping our equids that have evolved to exist on high fibre low energy forage slim can be very difficult. Pony breeds are especially susceptible to obesity, this is likely due to their ability to survive on thin air and also the exercise regime that they have. Obesity should be tackled through diet management and an exercise regime in consultation with your vet. Children's ponies often can't, or at least shouldn't, be ridden by adults and children are frequently busy with school or other activities. So this leaves their management as a main part of how their weight is controlled. Turnout in a large pasture is shown to maintain a level of fitness similar to a stabled and exercised horse. Lots of our horses are in small paddocks which limits their exercise, frequently obese ponies are kept in small areas with no grass, this will impact their ability to lose weight by exercise and also can be detrimental to their behavioural wellbeing.
Studies show that grazing muzzles do reduce grass intake, some found an average reduction of intake of 30% but other studies found a reduction of up to 83% of grass intake. It is apparent from these studies that sward length affects the ability of horses to eat with the muzzle on.
So, grazing muzzles allow restricted grass intake whilst out on grass, hopefully with their herd, exercising and we hope reducing or at least not gaining weight. A study showed weight loss when horses wore a grazing muzzle for 10 hours a day.
But, grazing muzzles can be hard on our ponies. Frequent and prolonged use of a grazing muzzle can result in tooth wear. Wearing a grazing muzzle is potentially going to be frustrating, having to work hard for every mouthful of grass wearing something that can be physically uncomfortable can't be easy. There are many different designs of grazing muzzle available but they all sit around the nose and limit grass intake. We should consider the effect on their poll, does the presence and pressure of a grazing muzzle strap affect their TMJ or put too much pressure on their poll causing discomfort? Do they affect breathing on hot days? We just don't know. If a horse or pony wears a grazing muzzle during the day and then has hay available in a small hole haynet they will find it difficult to satisfactorily consumate their goal of eating, which can cause frustration.

So how can we make life easier for them? Is there a right answer for weight control whilst still meeting their behavioural and physical need? There can't be a universal right answer, it has to be individual for that pony in their own circumstance. The things we do know are that in a natural state horses have minimal time between foraging bouts, often grazing is only interrupted by other needs such as sleep. A natural grazing break is frequently less than 1 hour but can stretch to 3 or 4 hours during movement or sleep, periods of time without forage (6 hours or more) can result in the formation of ulcers. A management system that ensures ponies are never left without forage is crucial, Redwings recently released a study where ponies achieved weight loss on a diet of hay and straw. Straw can be used as a forage with very low calories to ensure they are never without forage, it gives a second choice of forage and encourages foraging behaviour. If straw is to be introduced then it should be introduced slowly to reduce the risk of colic. Turnout in a large area helps to maintain fitness, turnout also allows the opportunity for social contact. Wearing a grazing muzzle can allow a pony to achieve these natural behaviours whilst limiting their grazing intake. Observation of your horse will allow you to observe any indications of frustration and their behaviour when approached with the grazing muzzle should be noted as it indicates how they feel about it. As a grazing muzzle can cause tooth wear this should be carefully monitored and the fit carefully checked to ensure there is no rubbing on the face.

If grazing muzzles are going to be used as part of the management they should be introduced slowly and gradually increase the time they wear it. Through careful introductions and training he muzzle can become the predictor of good things, if a treat is offered when it is put on, which also helps them to discover they can eat whilst wearing it. It can be beneficial to always catch or put on the grazing muzzle when they are going to do something they want for instance being turned out with their herd, when caught they have it taken off or come in for their free access hay. The horse should be monitored to ensure they are eating and drinking freely before they are left wearing it and the environment should be checked for hazards. A grazing muzzle should never be left on for long periods of time and the ponies always have an opportunity each day for a break and an opportunity to eat freely.

It should be noted that donkeys and their hybrids should not wear grazing muzzles. The National Equine Welfare Council provides an informative leaflet about grazing muzzles which can be accessed through the BHS website.

Well managed track systems and equicentral systems can be very beneficial alternative form of management for horses and ponies. Encouraging movement, social living and a diet of high fibre and low sugar forage. Temporary tracks can be created, bordering edges of spring, summer and autumn turnout so ponies can remain close to their herd whilst benefiting from a hay based diet with increased movement.

Enrich your horses life, provide adlib low quality forage, friends, exercise and as much freedom as you can give them. There is no right answer for every horse in every circumstance but we can prioritise what our equids require mentally as well as physically.

References

Graham-Thiers, P. Bowen, K. L (2013) Improved Ability to Maintain Fitness in Horses During Large Pasture Turnout Journal of Equine Veterinary Science Volume 33, Issue 8, August 2013, Pages 581-585

Geor, R, J.  Harris, P (2009) Dietary Management of Obesity and Insulin Resistance: Countering Risk for Laminitis Vol 25 (1) P 51–65 Vet Clinics; Equine Practise https://doi.org/10.1016/j.cveq.2009.02.001

Glunk, E. Sheaffer, C, C. Hathaway, M, R. Martinson, K, L. (2014) Interaction of Grazing Muzzle Use and Grass Species on Forage Intake of Horses, Journal of Equine Veterinary Science, Vol 34 (7) P930-933 https://doi.org/10.1016/j.jevs.2014.04.004

Glunk, E. C. Pratt-Phillips, S, E. Siciliano, P, D. (2013) Effect of Restricted Pasture Access on Pasture Dry Matter Intake Rate, Dietary Energy Intake, and Fecal pH in Horses, Journal of Equine Veterinary Science Vol 33 (6) P 421-426 https://doi.org/10.1016/j.jevs.2012.07.014