Laminitis (also known as founder) is a condition that horses and ponies can suffer that affects hoof structure and causes pain and varying degrees of lameness. It is the second biggest killer of horses after colic and affects the sensitive soft tissues connecting the pedal bone to the hoof wall (the 'laminae'). When this happens the pedal bone’s support becomes compromised and it can 'sink' downwards and 'rotate' backwards, causing irreversible damage.
This condition is often associated with ponies and many larger horse owners feel it is not an issue for them, however this is not the case. All horses can suffer it and those more at risk are often overweight horses and those feed high grain rich diets. Horses are generally diagnosed with laminitis in Spring time when the new, lush grass is coming through the pastures after winter, and once the horse has had one episode they tend to be predisposed to reoccurrences and require ongoing maintenance and preventative measures.
Laminitis most commonly affects the front feet of the horse. Some of the most common clinical signs of laminitis include shifting weight from one foot to another, lameness and palpable heat in the feet with increased pulses in the digital arteries over the fetlock.
Horses having an episode often have an increased heart rate and respiratory rate, and may tremble, sweat or be visibly distressed in severe cases.
The hooves are usually painful when pressure is applied over the toe region of the sole, and they may also have bruised or dropped soles, widened white line, dished hooves, squashed heels or flat feet.
Laminitis is usually caused by overeating feeds rich in soluble carbohydrates (mainly found in cereal grains and lush spring or autumn pasture).
Feeds rich in starches and sugars can cause a digestive upset in the large intestine. These energy rich nutrients are usually digested in the small bowel, however if eaten in excess they spill over into the large bowel, where they are fermented by certain species of 'bad' bacteria. This results in production of lactic acid in the bowel.
As the acid builds up and the normal bacteria in the bowel die, toxic substances known as 'endotoxins' are released and enter the bloodstream. It is these endotoxins which are thought to damage the laminae in the hoof.
It is best manage your horse to minimise the chances of developing laminitis.
Correct feeding, in conjunction with reducing acid build up in the bowel, are the most effective ways to prevent laminitis.
The basis of feeding horses with laminitis involves formulating a balanced diet high in fat and fibre while avoiding sugars (i.e. grains and carbohydrate-rich pastures).
This can be achieved by feeding mature lucerne hay that is typically lower in sugars and higher in protein than other hays. It is best not to feed rich cereal grain based feeds to laminitic horses, and when horses are suffering laminitis meadow hay is a better option to feed rather than oaten or Lucerne hay. However, new research now shows that Lucerne hay that has been soaked in water for at least an hour is proven to strip most lush sugars but still be nutritional enough to feed. This method can be time consuming and hay must be soaked each day to avoid mould.
Limiting the amount of pasture consumed by the horse will also help. In peak times such as Spring if the pastures have a lot of new growth and appear lush then limit access to these area by way of strip grazing, or simply removing them after limited times will also minimise excess consumption. Laminitic horses will require stricter programs to avoid recurrence and some may not be able to graze these lush pastures in peak times due to their sensitivity to relapse.
Products such as Founderguard contain 'Virginiamycin' are a great step towards preventing episodes and can be added to the feed daily in the lead up to peak time. This works by suppressing the activity of the 'bad' bacteria which produce lactic acid, thus maintaining the gut microbes in the correct balance. It is a useful product to aid in minimising the chance of laminitic episode and should be ideally given in the late winter months to build up in the system. This does not mean that other management issues should not be addressed and will not stop laminitis happening if they are still allowed excessive feeds.
Founderguard ideally a preventative rather than a treatment and cannot correct any physical damage that has already occurred in the feet. However, following an attack of laminitis, Founderguard can help prevent the 'flare-ups' that frequently occur in the recovery period. Once your horse is having an episode the damage is already done, so pain management, farrier attention and working with your veterinarian is the best option.
LONG TERM MANAGEMENT
Horses that have had laminitis once generally are more at risk of recurrence that those that have not. Initially, when the episode has occurred it is a good idea to get your veterinarian to xray the hooves to assess the degree of rotation that may have occurred. These xrays will also assist the farrier to have clear direction on the technique used to trim the hooves so as to best support the pedal bone and minimise further damage and lameness. Laminitic horses usually require regular trimming to avoid lameness every 6-8 weeks depending on the individual hoof growth. Long toes and flat heels are not ideal and often cause lameness.
The other aspect is general management from the owner. Avoid overfeeding with rich pastures or additional feeds and grains. Keep it simple approach is best. There are many feeds and additives available that may convince you to purchase and feed but most of the time, your laminitic horse is a “good doer” anyway and does not require all those extras. Generally for healthy hoof condition (and most of the time coat condition also) products that contain Biotin, such as BioBloom, will be sufficient to support the hoof and also contribute to a shiny coat without feeding fatty oils and other coat enhancers.
If feed is required then avoid lush Lucerne chaff or hay (unless soaked) and minimise grazing in the peak times where paddocks are forever green and thriving. Remember when feeding your horse if they are wormed regularly and there are no other health issues, and your horse looks healthy than there is probably no need to overdo the feeding regime.