Spring is just around the corner; this is an exciting time when the weather starts to get warmer, flowers start to bloom, and days get longer. Spring is also the time when most grasses will begin to return from dormancy and grow into beautiful, lush pastures.
Growth in pastures means you may be able to cut back on some of your hay costs by allowing horses to graze for some of their forage intake. However, it also means increased levels of fructans are present in many grasses; it is important to take precautionary measures when introducing your horses back onto pasture to avoid something that strikes fear into the gut of horse owners: founder.
What is founder?
Founder is a disease that occurs when the laminae of the hoof, which essentially function as Velcro and secure the coffin bone to the hoof wall, become damaged and inflamed. This can lead to separation of the hoof wall and the coffin bone, and eventually rotation of the coffin bone (1).
Founder is commonly used synonymously with laminitis, however they do differ slightly, as founder is considered to be a longer-term issue while laminitis is the acute occurrence (2).
What are the signs of founder in horses?
When the initial laminitis episode occurs, the horse may appear to be in pain standing and putting weight on their front feet, which will cause them to be restless or stand in the “sawhorse” stance with their front feet extended far out in front of them while rocked back on their hind legs to relieve pressure from the front feet.
Additionally, horses may have an increased digital pulse and heat in the legs/hooves (2). If the disease progresses to founder, horses will likely show rings in the hoof wall (over time), heels that grow faster than the toe, stone bruises in the sole, dropped soles, and widened white line (2).
If not treated, full rotation of the coffin bone may occur, and the bone may begin to protrude from the sole of the hoof. If the disease is not treated properly and is allowed to progress to this level of damage the horse will likely need to be humanely euthanized (2,3).
What causes a horse to founder?
Equine veterinarians and researchers are still working to determine exactly what the mechanism of founder looks like, but it is known to be complicated and has many factors.
These factors include:
- Toxins within the horse’s system
- Severe colic
- High fever, and
- Most commonly, digestive upset due to grain overload or access to excessive lush pasture suddenly (2)
Generally speaking, it is believed that the overload of starches or fructans will cause digestive upset in the large intestine, which leads to an acidic environment, causing further damage to the hindgut microbes as well as the intestinal lining.
Once this occurs, toxins can pass from the intestine into the bloodstream and may overwhelm the liver’s detoxification abilities. Toxins may then become systemic, travelling to the extremities where it can alter blood flow and cause damage and inflammation of the laminae. Once the laminae become inflamed and begin to degrade, the coffin bone may begin to rotate.
Horse founder treatment
The treatment for horse founder will likely be different for each horse and will depend upon the level of damage that has occurred (2,4). Founder is not a disease that can be diagnosed and treated alone; you will need to contact your veterinarian ASAP if you suspect early stages of laminitis.
The primary goal of treatment is to stop the progression of the disease, and then to manage the disease and the pain associated with it, as there is no way to truly reverse this disease once it has begun.
The first step in treatment is to identify and treat the underlying problem (i.e., grass founder in horses and subsequent gut upset). Your veterinarian may provide antibiotics and anti-endotoxins to reduce any infection or toxins in the body. Additionally, medication may be provided to help improve blood flow to the feet and laminae. Icing of the hooves may be recommended to reduce inflammation.
Once the onset of the disease has been addressed, long-term management will likely be necessary. A proper hoof care routine can be developed by your vet and farrier, and may include removal of shoes, use of therapeutic shoes or pads, regular corrective trimming, or special footing in stalls such as sand to evenly distribute weight on the sole of the hoof.
Additionally, horses may need long term pain relievers to manage their symptoms as well (2,4). If horses are prescribed antibiotics or long-term pain relievers, it may be beneficial to add ulcer protectants and probiotics to their routine to help maintain gut health.
Are some horses more prone to founder?
Extra care should be taken to prevent founder in horses that may be predisposed to developing laminitis. This includes horses that are overweight (think of those “easy keepers”), horses who have previously had laminitic episodes, ponies, donkeys, heavy breeds such as drafts, and horses who have Cushing’s/insulin resistance/Equine Metabolic Syndrome (1,2).
Preventing founder in horses
While some circumstances may be beyond your control, there are definitely steps you can take to help prevent founder from occurring in your horse.
- Avoid turning out horses, especially those prone to grass founder, on new pasture growth until the pastures have become longer and slowed in their growth.
- Feed horses their hay prior to turning them out on pasture, so they are full and less likely to binge on the lush grass.
- Turn horses out with grazing muzzles or for limited periods of time to minimize their grass founder risk (3).
And, finally, the most important preventative measure!
While further research is necessary, it is obvious that gut microbial health has a strong relationship to laminitis and founder (5).
Use of high-quality equine probiotics, like FullBucket’s Equine Probiotic Pellets, can promote a healthy gut, which may in turn help to prevent damage to the hindgut. Further, FullBucket’s Equine ADD Bioclay Plus Paste contains BioActive Clay which helps to remove toxins from the intestine prior to absorption into the bloodstream, which may help prevent toxins from becoming systemic if an insult has already occurred.
While grass founder may be intimidating, with the proper knowledge and management tools, you can ensure your horse can make it through the spring safe and sound with a happy gut and healthy hooves!