The Signs of Founder in Horses

 

These hooves show signs of previous founder – the waves, the long toe, the scooped out shape. 

 

What is laminitis in horses? What is founder?

 

• Laminitis and founder are often used interchangeably, but they are slightly different. Just because we can, let’s split hairs for a second.

Laminitis

 

• Laminitis is the swelling of the soft tissue laminae inside the hoof.

• The laminae are a series of folded and vascular tissues that run from the hoof wall to the coffin bone and anchor the bones in place. During a bout of laminitis, these tissues swell, constrict blood flow, and may cause the hoof bones to shift. There is severe pain as there is nowhere for the swelling to go – it’s trapped in the rigid hoof structure.

Founder

 

• Founder occurs when the coffin bone, also called the P3 or the pedal bone, moves within the hoof because the laminae are losing structure. The bone may shift, but pedal bone rotation happens as the tendons and ligaments of the lower leg tug on the bones, pulling them through the compromised tissue.

• You commonly hear “sinking” when referring to the coffin bone shifting. In severe cases, the bone will punch through the sole of the hoof. Founder is often a long-term condition.

• While both of these conditions are assumed to be only in the front feet, we now know that in most cases, all four hooves are affected, but that doesn’t mean all hooves will founder. Many horses with laminitis technically don’t founder.

Acute founder cases

 

• Acute laminitis and founder appear suddenly, almost out of the blue. In this acute stage, you will see the most obvious signs of hoof trouble and typical signs of founder.

• The acute stage, while surprising, has often brewed for months or years, as is the case with metabolic and endocrine disorders, but there has been a tipping point like overeating that triggers the laminitis.

 

Chronic founder

 

• Chronic laminitis and founder cases last weeks, months, and even years. Some horses have episodes or flares, where symptoms of laminitis and founder bubble up. It’s common for foundered horses to get foot sore after grazing, especially in the spring and fall.

• There are lingering changes to the hoof in chronic founder cases. Shifts to the pedal bone may not correct, and hoof anatomy may worsen. You will usually see abnormal hoof growth and divergent growth rings around the hoof that eventually grow out, and signal a time when trauma impacted hoof growth.

• Chronic cases usually have a wider white line, creating more opportunity for seedy toe, also called white line disease. Previous bouts of laminitis and founder also increase the likelihood and frequency of hoof abscesses.

Pain and pulses

 

• Some horses with chronic conditions tolerate a lower level of pain that may impact soundness; others seem to be pain-free.

• Knowing how to check your horse’s digital pulse can help your horse. In some cases of laminitis, a more robust digital pulse is your clue that the inside of the hoof is inflamed.

Knowing how to check your horse’s digital pulse can help your horse. In some cases of laminitis, a stronger digital pulse is your clue that the inside of the hoof is inflamed.

 

Laminitis and founder signs in horses

 

• The early signs of laminitis and founder are typically not very obvious. Subtle changes are much more common than the stance where a horse rocks back to relieve the pressure on the front hooves. While this is possible, only about 25% of laminitis horses show this behavior. There was a great study about this, which you can read here.

Things you may notice about your horse that are signs of founder:

 

• Increased digital pulse in the legs. Check all legs!

• Increased pulse and sometimes respiratory rates. These are both signs of discomfort.

• Tender-footed or sore after being shod or after eating grass.

• Hesitancy to walk, or walking as if on eggshells.

• Hesitancy to transition from a soft mat to a harder surface.

• Turning may look like a pirouette or pivot instead of their normal manner of turning. You may see shorter steps and hopping around.

• Shifting weight more frequently, or not at all. Some horses may also stretch out a front leg.

• Warm or hot hooves. This heat also indicates that your horse has been standing in the sun.

• Increased digital pulses. The stronger pulses happen in horses with any hoof problem, although not all horses show this.

• Colic signs. Signs of pain often mimic colic symptoms.

Signs of founder can progress to:

 

• Lifting of the front legs.

• Excessive lying down to relieve some pressure in the hooves.

• The coronary band hair starts to poke up as the bones drop into the hoof capsule.

• You may see a faint half-moon shape on the sole or other changes to the sole’s appearance.

• Severe pain and more colic-like signs.

• The toes and heels may start to look strange or longer.

• Because every horse is different and shows discomfort differently, the only way to monitor rotation and sinking of the pedal bone is with regular X-rays. Measurements of structures inside the hooves can track progress and healing.

 

• Checking for heat and a more noticeable digital pulse takes seconds.

 

Radiographs show the relationship between the coffin bone and the hoof wall.  When they are not parallel, something is amiss.  This horse looks fine in that respect. 

 

What causes founder?

 

• There are a few causes of founder, and one common underlying cause directly related to diet and weight – metabolic issues.

Metabolic issues

 

• Horses with metabolic conditions are more likely to founder.

• Equine metabolic syndrome (EMS) is a condition characterized by insulin resistance, obesity, and laminitis. A horse with EMS will become less sensitive to insulin levels; their body starts to create more and more of it to manage sugar levels. Insulin dysregulation is a primary cause of laminitis. In research settings, horses develop laminitis when insulin is administered.

• Pituitary pars intermedia dysfunction (PPID, formerly equine Cushing’s disease) also increases laminitis risks. This condition results from an overactivity of hormones released from the pituitary gland. This cascade of hormonal changes influences insulin regulation, thus increasing the risk of laminitis. While this does not fall under the umbrella of equine metabolic syndrome, some horses will also develop insulin resistance in conjunction with PPID.

Read more about PPID here, and EMS here. 

Sugars and starches in the equine diet

 

• When a horse with insulin dysregulation eats sugars and starches, their body over-reacts to those sugars, pumping out more insulin. If the sugars and starches are consumed too quickly or the volume is great, the other worry stems from hindgut microbes.

• When grains and concentrates quickly zip through the digestive system, large amounts of sugars and starches land in the hindgut to ferment. Sugar-loving microbes feast and create a lot of microbe waste, which changes the pH of the hindgut, creates gas, and kills other types of microbes, releasing endotoxins.

• The change in pH also makes the hindgut more permeable, so those toxins and waste pass through the gut’s wall into the bloodstream, where they have a one-way ticket to the hooves, creating laminitis.

Gorging on grass, grains, and hay will trigger signs of founder

 

• Any horse or pony that has the opportunity to gorge on grain, grass, or even hay can create digestive upset and trigger this reaction. The typical “pony in the feed room” situation applies to horses, too. There’s also a risk of colic from that gorging, too.

 

What your horse eats can have a direct impact on developing founder. 

 

Supporting limb laminitis

 

• Injured legs are often so painful that a horse will not bear the usual weight. Those other three legs then bear most of your horse’s body weight and can develop laminitis from all of that pressure.

 

• Fractures, street nails, cellulitis, lymphangitis, and other painful injuries may create supporting limb laminitis. Supporting limb laminitis is typically a slow development over weeks or months.

Road founder and repetitive trauma

 

• Horses that spend time pounding their legs on hard surfaces are susceptible to road founder. This may be the case for a carriage horse that spends hours upon hours on hard ground or the horse that escapes and runs up and down the road. Other types of repetitive trauma and concussion to the legs may also create a road founder situation.

Inflammatory diseases

 

• Laminitis is a real possibility when a horse has a systemic illness, such as colic, pneumonia, retained placenta in mares, colitis, or any other virus or bacteria infection. Fevers of known, or unknown, origin also put horses at risk.

• These inflammatory conditions affect the horse’s entire body and, thus, the hooves.

 

• Even fevers of known (or unknown) origin can trigger laminitis.

 

 

• Environmental factors such as black walnut exposure also trigger laminitis in horses. In the case of black walnut shavings, horses will develop laminitis within hours and are usually seen with swollen legs, too.

Specialty hoof boots provide ample cush for comfort. 

 

Diagnosis of Laminitis and Founder

 

• At the first signs of hoof trouble, talk to your vet. Founder and all of its horrors can be nipped in the bud if caught early. Diagnosis involves a clinical exam and imaging to start tracking internal hoof damage. Other diagnostic tests include:

• Vital signs, including digital pulses.

• A complete physical exam to understand your horse’s pain, symptoms, other causes of the pain, and complications like colic.

• There may be a lameness exam to determine the involvement in each foot. These exams can exacerbate pain, and your vet may want to administer nerve blocks to rule out other sources of trouble and to make the diagnostic process less painful.

• Imaging like radiographs helps your vet see the bones and establish an injury baseline.

• Hoof testers aren’t always reliable in sensing pain. When painful conditions overwhelm a horse, a lifted hoof often has relief and may not register hoof testers as there is excessive pain in the standing hoof. Hence, a false negative result to hoof testing.

Lab tests and venograms

 

• Bloodwork for metabolic disorders may need to wait, as increased cortisol due to pain will make some test results inaccurate. However, most horses can be tested for PPID right away.

• Another test, the Serum Amyloid A (SAA), looks for whole-body inflammation or infection. SAA levels rise in these cases. SAA levels won’t increase if the cause is dietary or metabolic. This test is one way to rule out possible causes.

• A venogram isolates the blood in the hooves with a tourniquet, and then a special liquid that shows up on X-rays is injected into the area below the tourniquet. This procedure maps the blood supply. A poor blood supply decreases the likelihood of a positive outcome.

Please call the vet pronto!

 

Reasons to call your vet early

 

• Most hoof problems look identical. Abscesses, bruising, foreign objects, bursitis, and more all present the same, and most have different treatments. Getting the proper diagnosis means healing begins sooner.

• X-rays will give your vet an accurate picture of the hoof’s bones and structures. These give your vet a baseline from which to monitor changes. Your farrier also needs these to provide support with corrective trimming, wedges, or special shoes. You can document the exterior and sole of the hoof with photos and notes.

• Anti-inflammatory medications provide pain relief and help with inflammation. There are many types; your vet can give you the best pain management plan. There is no reason for your horse to suffer when your vet can help you manage pain.

• More about bute, Banamine®, and Equioxx® here.

Keep peeling the onion layers

 

• You can begin ice therapy right away to alleviate the signs of founder.

• Your vet can provide a diagnosis and help decipher possible triggers. If metabolic issues are the root cause, which they most likely are, you can change your horse’s diet immediately and stop creating more complications.

• Early treatment reduces the likelihood that movement of the pedal bone will push through the sole.

 

• Please call your vet. Farriers are wonderfully talented healthcare professionals but cannot x-ray, diagnose, prescribe medications, and work deep into the soft tissues of the hoof. Certainly, call your vet and farrier to work together on any hoof problem, but please get the vet out quickly.

Checking for heat and a strong digital pulse takes seconds.

 

Founder treatments and supportive care to alleviate signs of founder

 

• Pain management and halting the progression of laminitis are the primary goals of treating founder in horses. Your horse’s plan might include:

• More ice therapy

• Stall rest with the deepest bedding you can give.

• Anti-inflammatory medications

• Medications to increase blood flow into the hoof

• Metabolic health supplements

• Prescription drugs for metabolic disorders are sometimes necessary

• A low NSC value diet, aim for 10% or less in all feeds and hay

• No pasture grazing until it becomes safer for your horse. Grazing muzzles can help mitigate risks when your horse can graze again.

• No treats, unless they are low in sugar.

• Corrective or adaptive trimming and shoeing.

• Specialty hoof boots can help add squish and comfort to your horse.

• There are surgical options, like severing the deep digital flexor tendon, but this is in extreme cases. This surgery stops the tendon from pulling on the pedal bone.

 

Grazing muzzles give your horse the most freedom to move, graze, and interact with the herd.

 

After Care for Foundered Horses

 

• Long-term lifestyle changes are often the best idea for foundered horses. You will need to:

• Feed your horse a low NSC value diet.

• Modify their exercise routine to accomodate their signs of founder that may linger.

• Have regular vet check-ups, including X-rays and blood work to monitor hooves and metabolic disorders.

• Track your horse’s weight. It’s easy with a weight tape.

• Use slow feeders and grazing muzzles.

• Practice good feeding habits, splitting up commercial feeds into many small meals.

• Work with your farrier to implement changes to trimming and shoeing.

 

Nutrition for Horses with Laminitis

 

• Feed your horse a diet low in NSC (non-structural carbohydrates) can keep metabolic problems at bay. Opt for grass hay, restricted pasture access, and appropriate supplements and feeds.

• Consulting an equine nutritionist can provide valuable guidance.

• Collaborate with your vet or nutritionist to identify supplements that support laminitis management. Supplements like magnesium, chromium, and Omega-3 fatty acids can be beneficial. Avoid molasses, and reconsider feeding corn, barley, and oats. If your horse needs extra energy, try rice bran.

• Change your horse’s treats. Instead of carrots and apples, offer hay cubes or low-sugar treats, ensuring you check their NSC values.

• Explore alternatives to traditional bagged feeds. Using supplements mixed with damp hay pellets can be an effective substitute for ration balancers or grain feeds.

• Always feed hay first. Before giving fortified feeds, concentrates, grains, or ration balancers, ensure your horse’s belly is filled with hay. The hay helps slow down the absorption of sugars into the hindgut.

 

How to feed

 

• Utilize slow feeders for all types of feed. Use special slow feeders for pellets, grains, cubes, and hay.

• Equip your horse with a slow feeder. Grazing muzzles act as face nets that slow down and limit the amount of grass a high-risk horse can consume.

• Provide a dry lot as an alternative to pasture. In some cases, horses should avoid pasture, and dry lots with multiple slow feeders offer an excellent solution.

 

There are tons of slow feeding options!

 

What breeds are most likely to founder?

 

Smaller equines and larger equines are more likely to founder. Ponies, mini horses, and drafts all have genetic predispositions to developing laminitis as they are more likely to be overweight and develop metabolic conditions.

 

Is founder permanent, or is full recovery possible?

 

Founder is not always a permanent condition in horses. With prompt and proper treatment, horses may recover from founder, but sometimes they are left with chronic founder. Recovery and healing require time and often changes to diet, lifestyle, turnout, exercise, shoeing, and veterinary care. Some horses will always show signs of founder.

 

There are a lot of super resources out there for horses, and all things hoof. One of them is Fran Jurga’s Hoof Blog. You can also read more about laminitis here:

 

First aid for laminitis

Laminitis myths

Acute and chronic laminitis

Help prevent laminitis

Risk factors for laminitis

Fall is risky for laminitis

Subtle signs your horse is unsound

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