Nutrition CPD July 2018

63

Feeding veteran horses

By Anna Welch BVSc, BSc, MRCVS. Veterinary Nutrition Director, TopSpec

There are many factors to consider when offering advice on feeding an older horse. Dietary requirements will vary e.g. according to the horse’s activity level, environmental conditions and any health concerns, so it is always helpful to obtain thorough information from the owner about their horse and his regime.

When is a horse a veteran?

A customer is likely to ask you the age at which their horse is classed as a ‘veteran’ and therefore, when you might recommend one of the senior or veteran products available. 

The answer to this question will usually depend on individual circumstances. Whilst it may be reasonable to consider a horse as a veteran from eighteen years of age, it is often more appropriate to act upon the signs associated with aging, or whichever comes first. 

Age-related health issues to consider

There are a number of factors that can affect the health of older horses and impact on feed intake, digestion, condition and ability to exercise. The following problems should be considered when reviewing the diet of a veteran horse:

(1) Reduced dental function: 

From a feeding point of view this is the most significant and inevitable problem to affect older horses. Over time the grinding surface of the teeth will wear down and horses may suffer from fractured or missing teeth, diastema (gaps between the teeth) and periodontal disease. A six-monthly visit from a qualified Equine Dental Technician or vet is essential to correct uneven wear, misalignment and food packing between teeth. However, there is only so much that can be done to delay the effects of wear before hay replacers will become necessary. 

(2) Musculoskeletal problems:

Mobility issues are frequently reported in veteran horses, usually from a culmination of wear and tear over the years, which can result in problems such as osteoarthritis. Reduced activity is often seen as a result and can lead to muscle wastage, poor circulation, weakening of bone and stiffness. Regular, gentle exercise and plenty of turnout can help to reduce stiffness. Dietary supplementation with the scientifically recommended level of glucosamine (10g per 500kg horse per day), as well as MSM, can also be beneficial. 

(3) Hormonal disease:

Pituitary Pars Intermedia Dysfunction (Cushing’s disease) is the most common hormonal disorder of veteran horses and ponies. Whilst PPID can affect younger horses, it is progressive and more frequently diagnosed in older horses. Insulin dysregulation is often associated with PPID and increases the risk of laminitis. Therefore, total diets should be low (<10 - 12%) in Non-Structural Carbohydrates (NSC) i.e. sugar and starch. Muscle breakdown (catabolism) can also develop as PPID progresses, so high quality protein is essential. 

(4) Respiratory disease:

From a lifetime of exposure to dust and spores, veteran horses can become prone to developing respiratory issues such as Recurrent Airway Obstruction (RAO). The key to management is reducing exposure to dust. This means that turnout should be maintained as much as possible and steamed or soaked hay, or haylage, used when necessary. 

(5) Immune system compromise:

As horses get older the strength of their immune system tends to decline. PPID can also affect immune function. To provide nutritional support for the immune system, diets should contain optimum levels of certain micronutrients particularly antioxidants such as vitamin A, E and selenium. Mannan Oligosaccharides (MOS) have also been found to be beneficial, whilst vitamin C has a role to play in lung health. 

Diet recommendations:

Forage

Forage is the foundation of any horse’s diet and veteran horses are no exception.

Fibre passes, undigested by the horse, onto the large intestine where it is fermented by the cellulolytic (fibre-digesting) bacteria. This microbial fermentation produces volatile fatty acids, which supply energy (calories) to the horse. This process also produces heat, which is an important consideration during winter, as older horses will find it harder to maintain their body temperature. 

A constant supply of fibre is essential to maintain a healthy digestive system, with optimal gut motility and balanced hindgut microflora. As a horse’s dental function declines, it becomes increasingly important to provide fibre sources that are easily chewed. 

During the spring and summer when grass is plentiful, a veteran horse living out can often manage well. Although, when incisor function is compromised grass will need to be sufficiently long for him to harvest it. 

Winter is a time of year that can highlight compromised dental function. Loose droppings, fluid passed after formed droppings or small, firm droppings can reflect insufficient fibre supply to the normal bacteria in the hindgut. Long, unchewed fibres are often seen in the droppings, even before quidding (dropping semi-chewed food) is observed. 

Haylage can be easier for a veteran to manage, because of its generally lower fibre content, particularly when compared to a mature, coarse hay. Straw-based chops should be avoided but soft, short chopped grass can be used as a hay/haylage replacer for a period of time. 

However, fibre in a pre-ground form rapidly becomes essential. A mash that is high in fibre, soaked fibre cubes and alfalfa/grass cubes, plus, to a lesser extent, unmolassed sugar beet pulp are all suitable alternatives to long fibre. Although, providing a horse doesn’t suffer from choke or impaction colic, it can be a good idea to continue to allow access to some hay or haylage as chewing on longer fibres can be mentally satisfying.

Hard feeds

• For the healthy veteran in good condition:

Horses that are able to maintain their level of work, without any significant health concerns, may be able to continue on their previous diet providing it is fully-balanced. The addition of a supplement including glucosamine and MSM may be sensible at this stage. Alternatively, there are top specification feed balancers available that include the recommended level of glucosamine and provide a very economical solution. 

• For the overweight veteran:

It is inevitable that workload will reduce for veteran horses, eventually leading to retirement. Energy expenditure will decrease, which can lead to unwanted weight gain for a healthy older horse.

Despite the fact than an elderly horse may be doing little or no work, it is important that he still receives essential vitamins, minerals and trace elements to balance his diet and support his general health. An ideal way to meet these requirements is by using a top specification ‘lite’ feed balancer or multi-supplement.

The best contain both general purpose and specialised supplements, which can include those for hooves, bone, muscle, blood, joints, the immune-system and the digestive tract. The use of one fully-balanced product, rather than multiple separate supplements, avoids unbalanced or over-supplementation. 

• For the underweight veteran:

As health issues start to develop, many veteran horses are likely to experience weight loss. 

Hard feeds should be nutrient-dense and not exceed the horse’s maximum meal size e.g. 2kg (dry weight) for a horse with an ideal bodyweight of 500kg. A top specification, conditioning feed balancer will supply amino acids, vitamins, minerals and yeast products, which improve the utilisation of the rest of the diet. This reduces the need for additional hard feed, helping to keep feed sizes small. 

Most top specification, conditioning feed balancers contain very high quality protein sources, which are rich in essential amino acids. Protein promotes muscle development and topline, which frequently wastes away in older horses. 

To provide further calories, highly digestible fibre sources, or ‘super-fibres’ should be used. Ingredients like unmolassed sugar beet pulp and oatfeed are examples of these. To increase the calories further, oil can also be added.

In view of the fact that older horses are gradually able to eat less fibre, and therefore may suffer from disturbances in the hindgut microbial balance, cereal-based products that are high in sugar and starch should be avoided. Digestible Energy (DE) values, similar to those of conditioning mixes, can be achieved without the use of cereals. 

Adding a low starch, conditioning blend to a top specification feed balancer, will provide a very successful solution for a veteran horse. 

Summary

• The condition of a veteran horse should be monitored carefully.

• Hay replacers, which provide pre-ground fibre, will become necessary as dental function declines. 

• Hard feeds should be kept low in sugar and starch and cereal-grain-free but provide high quality protein. 

• A fully-balanced diet is essential, with supplementation for the immune system, respiratory tract, joints and digestive system. 

TopSpec can be contacted, free of charge, on their BETA multiple award-winning-helpline tel 01845 565030