What is Laminitis
What is Laminitis?
Laminitis is a disease that affects the feet of animals that have hooves and is commonly seen in horses and cattle, affecting the foot in a number of different stages, from tenderness through to more progressive symptoms such as an inability to walk or in more severe cases can result in euthanasia.
The disease does appear in stages in affected animals, however, does require aggressive treatment in order to prevent the conditions becoming more painful, with more developed disease having the potential to result in the perforation of the coffin bone through the sole of the hoof.
What causes Laminitis?
There are multiple potential causes of laminitis in animals and being able to determine which of them was the definitive cause of the laminitis in horses or cattle is almost impossible to do, however, we have covered the extensive list of potential causes you need to consider.
The list of potential causes of laminitis are broadly categorised into groups to allow us to be able to reference to smaller sections of potential causes that could have led to an animal suffering with the laminitis disease;
Carbohydrate Overload – This is one of the most common causes of the laminitis disease and relates to a horse being given too much grain within their feed or eating grass under stress, both of which result in a build-up of excess sugars, starch or fructan (non-structural carbohydrates).
When this happens the horse is unable to digest all of the carbohydrate intakes within the foregut and is there for passed through the body to the hindgut, where it is allowed to ferment once it reaches the cecum.
It is at this point that the fermentation causes an increase in the amount of acidity found within the cecum, killing beneficial bacteria that are tasked with fermenting fiber within the body.
With the bacteria now unable to complete the task, endotoxins and exotoxins are created and make their way into the bloodstream, resulting in widespread inflammation of the horse’s body, particular within the feet where swelling tissue has nowhere to expand which causes the pain.
Nitrogen Compound Overload – Horses are herbivores and graze the land, meaning that they learn to deal with a ‘normal’ level of non-protein nitrogen compounds found within their grazing, however, should that level rapidly increase their metabolic process becomes unable to deal with the levels and becomes overloaded.
One of the most common reasons that the nitrogen compound levels are increased at a rapid rate is the grazing of lush spring grass that is grown on fertilised lowland grassland while another is if a grazing area is overrun with legume (clover).
Colic – This is a problem at is often found in horses and if a horse suffers from a serious case then it can become a cause for laminitis due to endotoxins being released into the bloodstream.
Lush Grazing – A potential cause that will concern many horse owners, particularly those that stable throughout the winter months, as lush grazing can become a true cause of laminitis in your horse if they are not used to the fructan levels that the grass provides.
It is more commonly found in smaller horses and ponies than larger horses.
Frosted / Frozen Grass – There is a correlation between freezing temperatures and laminitis symptoms being seen in horses and that is because the colder temperatures cause the grass found within your paddocks and grazing areas to stop growing.
When the growing of the grass stops, there is a build-up of excess sugar that is not being used within the grazing and those levels can result in horses being subjected to higher insulin levels, something that has been found to cause laminitis.
Untreated Infections – If you allow an infection to go untreated in your horse, you are putting it at risk of developing laminitis due to the bacteria which grows within the infection.
These bacteria then aid the release of endotoxins into the bloodstream, where they can then cause inflammation.
Insulin Resistance – Horses that have insulin resistance tend to be able to become obese very quickly, even when grazing can be limited, and while the complete process in which suffering from insulin resistance is not yet completely understood, the exposure to increased sugar and starch within the diet can result in laminitis.
This type of cause is one of the hardest to determine initially, however if you believe that your horse could potentially be resistant to insulin then it is important that you remove your horse from green grass grazing and only allow them to only eat hay that has been tested for non-structural carbohydrates below 11% on a dry-matter basis.
Mechanical separation is also known as ‘road founder’ and occurs when horses that have long toes are worked over long periods of time on the hard ground, resulting in a laminae breakdown that happens over time.
Historically this cause was more common in carriage horses that were worked for long periods of time driving on hard road surfaces, however, it is also found in heavier horses that have slim legs and relatively small hooves.
Although the ties have been made towards horses that suffer prolonged work on hard surfaces, ‘Road Founder’ has become evident in horses that have become overweight too, including ponies during the spring months of grazing and pregnant mares.
Poor Blood Circulation
Horses can develop poor blood circulation is they are not actively moving about and moving their lower limbs frequently as those that lack sufficient movement can be found to have stagnant anoxia which has been found to cause laminitis in previous cases.
Not just inactive horses are at risk of developing poor blood circulation either, even the most active horse can suffer leg injuries and will attempt to compensate its weight across the uninjured legs to relieve pressure and pain, making it at risk of static laminitis, especially if recovery involves the horse being placed on ‘box rest’ for a considerable time.
That have been a number of high-profile cases of horses that have suffered static laminitis, such as Barbaro, the winner of the 2006 Kentucky Derby.
Complex Causes of Laminitis
- Cushing’s disease (Pituitary pars intermedia dysfunction) is a common link between older horses and ponies and laminitis.
- Equine metabolic syndrome – Closely tied to insulin resistance and cortisol metabolism, it is believed to play a major role in laminitis and has similarities to type 2 diabetes.
- Retained placenta that is not completely passed during birth is believed to lead to bacterial fever and toxicity within the body.
- Agrichemicals exposure through grazing has been tied to laminitis and causes of the disease, including herbicides and synthetic nitrate fertilisers.
Laminitis Risk Factors
Although there is a large amount of evidence to suggest that diet plays a major part in horses getting laminitis, there is also a case for relevance to be made towards a horse’s condition and breeding playing an active role too.
With hormones such as adiponectin as well as serum insulin able to be measured in horses, it provides possibilities that could see further research creating effective testing procedures that could identify subjectable horses before laminitis develops.
What are the symptoms of laminitis?
- An increase of heat that is found within the hoof of the horse, including walls, sole and coronary band.
- Heavy pulsing heartbeat evident in the digital palmer artery.
- Stress, anxiety and shaking (trembling).
- An increase in body temperature.
- Nostrils flared.
- Tender walking position.
- Consistent shifting of weight from one or more feet while either walking or standing.
- Lameness that returns a positive response to hoof testers at the toe.
- A desire to lay down at every possible opportunity rather than stand.
- Change in the look of the outer wall of the hoof
To be able to effectively treat laminitis there needs to be a clear decision regarding whether you are dealing with the acute onset of a laminitis attack or a chronic situation as the treatments will be different for each case.
There is no cure for laminitis, simply treatments that are designed to help you to take pre-emptive precautions against further cases of the disease occurring or in cases that are past the point of that being possible, methods that can help to slow the effects and development.
In order to establish the best treatment for laminitis, it is suggested that you should speak to your vet and ask for x-rays to help determine the effects that the disease has already had on your horse’s feet, from there you will be told the options that are available to you.
We highly recommend that should you believe that your horse could be showing possible signs of laminitis that you do not ignore them, instead take your horse off green grass grazing and call your vet for further advice as identifying the problem early will make treatment easier.