The right diet forms the basis of good health at every age, providing energy and strengthening your horse’s immune system to leave him better able to fight off illness and infection. The bulk of his intake should be forage, which will maintain gut function.
The ability to chew and digest food efficiently will ward off malnutrition, weight loss and colic and set your horse up for a vigorous old age.
Regular work is beneficial, boosting muscle tone and promoting heart and lung health. Build fitness gradually, allowing time in each session to warm up and cool down.
Timely and targeted vaccination and worm egg counts will contribute to your horse’s future health, so don’t skimp on routine care.
Stress and anxiety may accelerate ageing. Provide company, stimulation and as much turn-out time (below) for your horse as you can.
Tendons and ligaments
Strengthening of the musculoskeletal system starts in early life, explains Liz Barr MRCVS of Bell Equine, who advises an “appropriate amount” of exercise in the young horse to build foundations for his athletic future.
“Tendons and ligaments have been shown to be able to adapt to exercise before the horse reaches the age of two,” she says. “After this, the potential to strengthen in response to exercise is lost and any further exercise will only accelerate the normal degeneration or ‘wear and tear’ that occurs as a result of the ageing process.
“Damage can be due to either cumulative small injuries, leading to eventual failure, or as a result of one bad step, which causes a single traumatic incident and failure. Exercise can be protective, however, bad steps and tripping are more likely to occur with fatigue.”
A tendon can be likened to a slinky toy, says Liz, in that it will spring back when stretched unless stretched excessively, at which point it can never regain its original structure.
“The same is true of the wavy structure of tendon fibres,” she explains. “Tendons and ligaments are placed under greater stress when structures are working at maximum level — during fast work, over uneven ground or in excessive small circles. To protect these structures, use a good farrier and make sure that your horse’s feet are correctly trimmed and balanced. Be choosy about surfaces and try to avoid rutted ground and deep mud when hacking.”
Liz advises a varied exercise programme to maintain cardiovascular fitness, without doing too much of one thing.
“I was taught long ago that any horse only has so many jumps in him,” she says. “Save those for the ring, to maximise his athletic life.”
Obesity is thought to accelerate the ageing process in humans, but does it have the same effect on horses?
“There is no evidence linking obesity to premature ageing in horses, although, anecdotally, it is often suspected that obesity predisposes horses to PPID [the hormonal condition, pituitary pars intermedia dysfunction, previously known as Cushing’s disease],” says Professor Andy Durham of Liphook Equine Hospital. “Clearly, obesity is strongly linked to laminitis, which is a common reason for euthanasia. Reducing the risk of PPID and laminitis, therefore, with a diet appropriate to a horse’s body condition and exercise level, will, in all likelihood, prolong his life.”
Air quality plays a fundamental role in lung health, says Catriona MacKenzie MRCVS of Rossdales Veterinary Surgeons.
“In humans, dust exposure has been shown to have a long-term detrimental effect on respiratory function and results in an increased prevalence of chronic lung disease,” she says. “Such exposures are likely to have similar effects in horses. Inhaled environmental factors play an important role in a number of lung diseases, such as inflammatory airway disease (IAD) and equine asthma [also known as recurrent airway obstruction (RAO) or COPD].”
Air quality is determined by sources of potential contaminants, including feed and bedding, activity within indoor stabling and ventilation, as well as traffic pollution or high pollen levels. Catriona recommends feeding good-quality hay or complete pelleted feeds, using dust-free bedding and removing your horse from the stable while mucking out.
But what role does exercise play?
“While moderate, regular exercise can have a beneficial effect on lung function, prolonged or intensive work is known to increase susceptibility to respiratory infections,” she says. “Age is a further contributing factor. Young horses are more susceptible to viral infections than older horses and intensive exercise potentiates this risk.”
The heart will outlive the horse in the vast majority of cases, according to Philip Ivens MRCVS of Buckingham Equine Vets.
“Like any muscle, keeping the heart fit is good for it,” says Phil, who recommends a gradual and well thought-out exercise programme. “Rarely, a valve or component fails. Given a horse’s inherent athletic potential, his heart is pretty robust.”
A major cause of human heart disease is atherosclerosis, which is a complex disease related to diet, genetics and environmental factors, such as diet and/or cigarette smoke.
“Horses do not get this,” he says. “The most common age-related change in the equine heart is valvular endocardiosis of the aortic valve, which degenerates and becomes nodular or thickened with scar tissue. This typically occurs in teenage years and is thought to have multifactorial causes.
“To our knowledge, diet and lifestyle do not affect equine heart health, certainly not to the degree seen in dogs and humans,” adds Phil. “But the cardiovascular effects of equine metabolic syndrome, usually the result of obesity, is an area of active research. One recent study showed an increase in heart muscle thickness linked to insulin resistance.”
So what else will promote heart health?
“Take your horse’s heart rate and know what is normal,” says Phil. “Regular veterinary checks are a good idea and abnormalities should be investigated. Equine asthma [also known as recurrent airway obstruction (RAO) or COPD] should also be managed correctly, as this can cause an increase in work for the right-hand side of the heart, with the potential for failure or cardiac rhythm abnormalities.” H&H
Equine eyesight deteriorates with age, although few older horses show evidence of visual disability.
“All horses over age 18 will have some degenerative change in their lenses, in the form of cataracts, and in their retinas,” says Dr Andy Matthews FRCVS. He adds that the reason for this is not yet known. So can anything minimise the risk of eye disease, age-related or otherwise?
“There is no way of preventing it,” he says. “Tests to predict and then prevent the more common diseases are not yet available. The most important thing an owner can do to avoid permanent injury is to promptly seek veterinary help where there is ocular pain, a swollen, red eye, or white/grey cornea. Early intervention will markedly improve outcomes.”
Ocular problems arising from prolonged exposure to airborne particles, including bacteria and fungi, are remarkably rare, adds Andy, although it makes sense to keep stables as free from dust and ammonia as possible. A balanced diet based on grass and grass products is also beneficial.
Ref Horse & Hound; 15 June 2017