Hoof Health Unveiled: What is Quarter Flare/Separation and how is it different from White Line Disease?
I get asked this question often from horse owners.
Let's talk Quarter Flare to start.
There are two issues that can cause the quarter to flare, first is mechanical stress placed on the hoof itself, the second is metabolic stress.
In a healthy hoof, the bond or interdigitation of the sensitive lamina to the insensitive lamina is tight. This connection is the white/golden line we see on the bottom of the hoof. The golden line is formed by the terminal papillae's around the rim edge of the coffin bone as they secrete a flexible type of keratin. This keratin (golden line) acts like a silicone bond between the two structures of lamina. Flexibility is key, as the insensitive lamina grows down and past the sensitive lamina that stays attached to the coffin bone itself. Because this bond must be flexible/elastic to join these two structures, it is the weakest part of the horse's hoof. This bond can be broken by mechanical stresses put on the hoof.
Mechanical stress is created when the hoof is allowed to grow too long, decreasing the ability of the frog to perform its role of providing support in the rear/center of the hoof, which then causes the full weight of the horse to push down on the hoof wall (peripheral loading). The weight and loading of the hoof wall can cause a great deal of leverage on the golden line which is how the quarter flare starts. As the wall moves away or flares, the golden line must stretch to cover the increasing distance between the two laminae. If the stress continues due to a long trim cycle or improper trimming, the golden line can break down, leading to the separation of the wall from the sole. When this separation happens, the golden line expands to cover this distance (lamellar wedge).
To treat quarter flare caused by mechanical stress a shorter trimming cycle should be implemented with regular maintenance trimming being performed every 2-3 weeks, allowing the frog and heels, to bear the primary impact of the footfall and not the hoof wall.
Metabolic Stress is a breakdown at the cellular level of the hoof. Systemic metabolic conditions such as stress, insulin dysregulation, PPID, obesity, mineral imbalance, dietary imbalance, or infection can cause a weakness within the cells of the hoof. This breakdown can cause issues within the hooves and the ability to create and maintain the strong bond between the laminae. Signs of metabolic conditions that show up in the hoof can be slow growth, angle changes to the hoof wall, brittleness, ridges, and fine line cracks in the hoof wall.
What is White Line Disease?
Any weaknesses of the lamellar attachment can lead to microscopic openings for fungi and bacterial microbes to gain entry which can lead to infection. This infection can result in large cracks and chips, and separation as the golden line (the “silicone” that joins the sole and hoof wall) gets “eaten” away. As this bond weakens and if any metabolic conditions, improper trimming techniques or long trimming cycles are not addressed and corrected this can lead to the development of White Line Disease (seedy toe) in the hoof.
The best defense against White Line Disease is prevention! Do not let the hoof wall peripherally load the hoof, and make sure any wall leverage is kept to a minimum with a good balanced trim and trim schedule. If you see a small cavity or separation in the golden line, make sure to first address the leverage that likely caused it, and second treat the area topically to prevent the microbes from taking over. My favorite treatment for non-invasive separation is to gently remove any debris from the area and to apply Artimud into any cracks or crevices that are present. For serious, invasive (more than a few mm of separation) cases of white line disease that are eating up into the area, I soak the hoof twice weekly with White Lightning, a liquid soaking solution first and then treat topically with Artimud for turnout.
Remember, quarter flaring, separation, and white line disease are all secondary conditions that are caused by leverage or a weakness within the hoof. First, address the cause of the weakness, and you will likely resolve the secondary issues.
Product Application Video - Sole Cleanse, Artimud, and Hoof Stuff
Thrush is a common hoof condition in horses that affects the frog and can have serious consequences to the health of the hoof. It is caused by a fungal and/or bacterial infection and is more common during wetter weather. Thrush can create a foul-smelling chalkiness on the frog and in the collateral grooves, and can impact the shape and size of the frog. In severe cases thrush can infect the digital cushion of the hoof, this is a sensitive, shock absorbing structure in the rear of the hoof that is responsible for dissipating the impact vibrations during movement!
Here's some helpful information on the symptoms, treatment, and prevention of thrush in horse hooves:
1. Foul Odor: One of the most noticeable signs of thrush is a strong, unpleasant odor emanating from the frog or collateral grooves when you pick the hoof out. This odor is caused by the fungus and/or bacteria and decaying tissue.
2. Black or Gray Discharge: Thrush often leads to a black or gray, moist discharge in the central sulcus of the frog or in the deepest parts of the collateral grooves. This discharge may also be accompanied by a cottage cheese-like consistency.
3. Sensitivity and Lameness: Horses with thrush may become sensitive or lame, particularly when pressure is applied to the affected area. They may show discomfort when picking out the affected hoof and an inability to load the back of the hoof during motion - resulting in toe first landings.
4. Changes in Hoof Appearance: As thrush progresses, it can cause the frog to become soft and spongy. In severe cases, the frog may even develop deep crevices or cavities.
Treatment of thrush in horse hooves involves several steps:
1. Cleaning: Begin by cleaning the affected hoof thoroughly. Use a hoof pick to carefully remove dirt, debris, and any loose or decayed tissue from the frog. Using the Sole Cleanse product after this process helps to disinfect the frog and sole prior to packing with Artimud or Hoof Stuff.
2. Topical Treatments: Various topical treatments are available, such as Artimud, which is formulated to treat minor thrush and work as a preventative, and Hoof Stuff, which is formulated for deep central sulcus cracks. Using the Artimud product provides lasting protection against damage. It contains naturally active agents that eliminate bacteria and fungi and promote the formation of healthy tissue. It can be reapplied on a daily basis. For the deeper crevices in the central sulcus, Hoof Stuff is the best choice as it will stay in place with its cotton fibers, zinc oxide and honey base. For best results top the Hoof Stuff with Artimud!
3. Proper Trimming: Regular trimming and maintenance of the hooves are essential to prevent the accumulation of debris and provide better aeration to the frog. For more info on proper trimming and how to evaluate your horse's trim consider our Online Hoof Anatomy, Theory and Barefoot trimming Course.
4. Dry Environment: Ensure that the horse's living environment is clean, dry, and well-maintained. Mud and moisture can contribute to the development of thrush.
Preventing thrush is key to maintaining hoof health:
1. Regular Hoof Maintenance: Schedule regular hoof trims every 4 weeks with your trimmer to keep the hooves in good shape and prevent the accumulation of debris.
2. Clean and Dry Environment: Ensure that the horse's stall, paddock, and pasture are clean and free of standing water or mud. Proper drainage can help keep hooves dry.
3. Proper Nutrition: Maintain a balanced diet to promote overall hoof health. Adequate nutrition is essential for strong hooves.
4. Regular Exercise: Encourage your horse to move and exercise regularly, as this helps with blood circulation and hoof health.
5. Routine Checkups: Regularly inspect your horse's hooves for signs of thrush, especially in wet or muddy conditions. Early detection and treatment can prevent the condition from worsening.
6. Hoof Boots: Consider using hoof boots if your horse is prone to thrush or has sensitive hooves. These can help protect the hooves from moisture and debris.
If you suspect your horse has thrush or if the condition persists despite your efforts, it's essential to consult with a veterinarian or farrier for a proper diagnosis and treatment plan tailored to your horse's specific needs.
I had spoken on the phone to the owner of this horse prior to arriving and I was prepared to deal with a foundered horse, but I wasn't aware of the severity.
This horse has been under veterinary care and was seen by the farrier every 4 weeks for the last few months. There are also underlying PPID and IR issues.
This horse has been very lame for the last year.
The only radiographs I had to work with were from 6 months previous. They show significant sinking and rotation, but I suspect the damage is even worse judging by the current state of the hooves. Current radiographs would be extremely helpful, but in this case they are not available.
While this trim seems fairly drastic, I am sure I could have done more if I had current x-rays. This was a step in the right direction to restore function and set up the new growth for coming in. The owner purchased Easyboot Clouds to keep this horse comfortable moving forward and we plan to trim every 3 weeks to start.
In the pictures above you can see the huge lamellar wedge. There is so much separation in this hoof wall. I also tried not to touch the sole at all, what I did trim on the bottom was the overlaid bars and overgrown frog. I also tried to lower the heels to realign the bottom of the coffin bone. This horse has very thick bone, and will naturally have a slightly longer heel then the average 1.25 inches because of that.
From a metabolic standpoint this horse is on low sugar hay in slow feed nets placed around her paddock to increase movement, I also suggested adding biotin to her diet to help with hoof growth, and rechecking her ACTH levels to make sure her Pergolide dosage for her PPID is effective.
I will update this case study with more picutres next time I see her.
Kristi Luehr is a barefoot trimmer/farrier, author, and founder of the Okanagan School of Natural Hoof Care. She is certified by the Canadian Farrier School as well as the Oregon School of Natural Hoof Care, and also has certification in equine massage and dentistry. Her focus is to educate owners about hoof anatomy, function and proper barefoot trimming that supports and grows healthy and functional hooves specific to each horse's individual needs. She is the author of three online courses specific to hoof care and is always striving to create more educational content for students to learn from.