The adage “prevention is better than cure” applies no better than to the disease referred to as laminitis. Historically, laminitis has been primarily a problem of the Spring and sometimes Autumn periods when grass growth was greatest. I am sure we have all noticed that the seasons are less well defined now – after all Summer clearly happened in April this year! For this reason, laminitis must now be regarded as a risk throughout the year. The condition causes considerable pain and discomfort to those afflicted and, sadly, ponies and horses are put down every year as a direct result of the disease. This sad outcome more often than not can be averted by a basic understanding of laminitis and its causes.
Even now, we do not fully understand all the mechanisms by which laminitis arises in individual animals and it is unclear why some individuals appear to be more susceptible even under identical management conditions. It is a false sense of security to assume that an animal that has not had laminitis in previous years will continue not to be afflicted. Always assume the condition is lurking around the corner!
So what is laminitis? Briefly, laminitis is a condition that results from the disturbance of the normal bloodflow to the foot. The damage caused to tissues in the foot through reduced bloodflow causes acute pain. The degree of damage and level of pain are influenced by how long the blood supply is disturbed. Treatment is aimed at restoring bloodflow as soon as possible to minimise the structural damage in the foot that will otherwise occur. EARLY recognition of the di
sease is therefore of paramount importance.
While the precise nature of the condition is still being researched, we are aware that certain situations predispose laminitis and the following observations can be made:
(1) Overeating/Overweight – the vast majority of laminitis cases are seen in ponies with access to excess grass. With an ever increasing grass growth
period, there is now less seasonality to the condition than in the past. Many of the native breeds of pony have evolved to survive on poor, limited and variable vegetation. Modern pasture management produces excessive amounts of higher quality vegetation than these animals require. Many ponies only undertake limited exercise – excessive consumption with limited exercise provides the perfect recipe for laminitis. Furthermore, there is an inclination for owners to give supplementary feed even at the height of the grazing season! Most ponies and indeed many horses can meet all their nutritional requirements from grass and conserved forage (hay etc). Hard (cereal based) feeds are often fed unnecessarily and in some cases detrimentally. There is some evidence to suggest that it is changes in the composition (especially certain sugars) of the grass at certain points in time that trigger laminitis. It is clear that simply being overweight does not automatically cause laminitis and a thin animal is not immune from the condition either.
(2) Toxaemia – this means the presence of toxins in the blood. Toxins may be produced from infections (for example, mares that fail to shed the afterbirth after foaling). Toxins can also be produced in the gut if a horse or pony overeats concentrate feed (for example, breaking into the feed bin) since the excess feed can allow certain undesirable bacteria to multiply in huge numbers, killing off the normal bacteria found in the gut and producing toxins which are absorbed to trigger the disease.
(3) Drug-induced laminitis – some drugs, most particularly corticosteroids, may trigger laminitis though the mechanisms are not well understood. Such drugs are sometimes used to control diseases such as “sweet-itch” or used to medicate joints. The risks must be weighed up against the benefit in each animal, especially if an animal is regarded as high risk for laminitis.
(4) Trauma – excessive hard ground work or over-loading one limb through injury to another limb may provoke laminitis-like changes.
(5) Other disease – certain diseases such as “Cushings Disease” can increase the risk of laminitis in an animal and careful management is often required in such cases.
If the potential conditions in which laminitis can occur are known, then it is far more practical to take measures to prevent the condition in the first place. Attention to the physical condition (weight) of an animal throughout the year is required. If an animal is not working because of injury or retirement, then restricted grazing may be essential – this may be through limiting grazing time or limiting grazing availability (e.g. strip-grazing). Ask the farrier to check for any signs of laminitic change in the foot. Even poor looking pasture can be too much for some animals during peak growth periods.
Animals used for showing are often overweight (clinically obese) due to the whim of the judges. Always put the health of your animal first! During periods of low grass availability, most animals will thrive on hay and other conserved fibre sources. Feed costs in many animals can be significantly reduced since many are fed more than they require.
If you suspect laminitis in your horse or pony, seek veterinary advice at the earliest opportunity. The animal should be put into a clean stable with dry supporting bedding material such as shavings. The aim is to correct the blood flow to the foot as quickly as possible to minimise tissue damage and speed the recovery process. Anti-inflammatory drugs may be used in the early stages to improve comfort and help reduce damage. Laminitic animals should not be forced to exercise since this may further damage the tissue and compromise blood flow. The vet may advise X-raying to see what is happening within the foot, especially to the pedal bone enclosed within the hoof. Special supportive shoes may be required and vets and farriers need to work in close alliance to help more severe cases.
In summary, never underestimate the potential for laminitis to occur, especially now when the risk period is wider than ever. Act sooner rather than later if you suspect laminitis in you own animal.
Newnham Court Equine Clinic 01622 737884