Seedy Toe in Horses: Signs, Causes, Treatment and Prevention (Australian Guide)

Seedy toe is an anaerobic bacterial and fungal infection that invades the white line of the horse's hoof, the junction where the hoof wall meets the sole.

In a healthy hoof, the white line is a tight, continuous seal. When that seal is compromised (by mechanical stress, laminitis, long toes, a crack, or simply wet and unhygienic conditions) opportunistic bacteria and fungi move in. Because they're anaerobic (meaning they thrive without oxygen), the dark, enclosed space inside the hoof wall is exactly the environment they love.

Once established, the infection breaks down the keratin protein in the hoof wall, creating a crumbling, hollow cavity that gradually undermines the structural integrity of the entire foot. In the toe area, this gives rise to the colloquial name "seedy toe." When it occurs elsewhere along the hoof wall (at the quarters or heel) it may be referred to more broadly as white line disease.

The condition is sometimes confused with thrush, but they're distinct problems. Thrush affects the frog, sulci and sometimes sole on the underside of the hoof. Seedy toe affects the white line and inner hoof wall.

Read more about Thrush here

Wet-dry cycles are particularly damaging to hooves.

In most parts of Australia, horses experience significant swings between wet, boggy winter paddocks and hard, baked summer ground. This constant expansion and contraction of the hoof wall (swelling when wet, shrinking when dry) stresses the white line and creates micro-separations where bacteria can enter.

Long toes in horses are a major contributing factor.

Australian horses on large properties or those struggling to find farriers to service them, often go longer between farrier visits than is ideal. The longer the toe, the more mechanical force is applied to the white line with every step, stretching and pulling at the laminar junction until it starts to separate.

Laminitis history in horses increases risk.

Australia has a high prevalence of laminitis, particularly in horses and ponies on pasture. When laminitis causes the coffin bone to rotate even slightly, the white line stretches and weakens, creating the perfect entry point for seedy toe infection. Many horses with a history of founder will battle recurring seedy toe as a direct consequence.

Read more on laminitis here

What you might see from the outside

• A vertical crack or flare at the toe or quarter of the hoof
• The hoof wall appears to be peeling away or separating from the sole at the white line
• A visible dark line, gap, or crumbling material at the white line when the hoof is picked out
• Dirt and debris packing into a widened white line area
• A cavity visible at the toe when the hoof is viewed from the sole
• In advanced cases of white line disease, a section of hoof wall that sounds hollow when tapped. Run your knuckles across the wall from heel to toe; healthy hoof gives a solid thud, advanced white line disease where there is an empty cavity of ongoing infection will sound hollow when tapped.

What your farrier or trimmer will find

• A cavity between the inner hoof wall and the sensitive laminae with a black appearance
• Black, grey or chalky crumbling horn material filling the cavity
• In more advanced cases, a cavity that extends upward, sometimes nearly to the coronary band
• Occasionally, an abscess forming as a secondary complication

When lameness appears

Most horses with mild to moderate seedy toe are not lame. When lameness does occur, it usually signals one of three things: the infection has reached the sensitive inner tissues, an abscess has formed, or in serious cases, the coffin bone is under pressure from the structural collapse of the hoof wall. If your horse is lame and seedy toe is suspected, you'll need to involve your vet.

Understanding why seedy toe develops is the key to preventing it. The most common causes are:

Long toes and infrequent trimming

When the toe grows beyond the ideal length, the white line is put under enormous mechanical shear with every stride. Regular trimming (ideally every 4–6 weeks) keeps the toe length in check and reduces this stress.

Previous or ongoing laminitis (founder)

Laminitis stretches and damages the laminar connection inside the hoof. Even mild, subclinical laminitis can widen and weaken the white line over time, making it far more vulnerable to pathogen invasion.

Wet conditions and poor drainage

Hooves that are consistently wet become softer and more permeable. The white line, normally a tight seal, loosens when saturated, allowing bacteria and fungi from soil and manure to enter.

Hoof wall cracks and injuries

Any break in the integrity of the hoof wall (whether from a toe crack, a lost shoe, or an injury) creates an entry point for infection.

Poor hoof conformation

Horses with low heels, long toes, flat soles, or significant flare in the hoof wall are anatomically more prone to white line stress and separation.

Nutritional deficiencies

Inadequate biotin, zinc, copper and methionine can compromise hoof horn quality, making the wall more brittle and porous. This is worth discussing with your vet or equine nutritionist if you have a horse with chronically poor hoof quality.

Step 1: Get your farrier or trimmer involved immediately

The first and most important step is to have your farrier or barefoot trimmer assess the hoof as soon as possible. Do not wait until the next scheduled appointment if you suspect seedy toe. Early intervention makes resolution far simpler.

Your hoof care professional will:

• Clean out the white line area thoroughly with a hoof knife and pick
• Remove all crumbling, infected horn from the cavity
• In more advanced cases, perform a resection, opening up the affected section of hoof wall to expose the infection to air and allow topical treatment to reach it
• Assess whether the cavity has extended upward toward the coronary band
• Advise on trimming frequency going forward (shorter intervals, sometimes as little as 2–4 weeks, are recommended during active cases)

The goal of debridement and resection is twofold: remove the infected material, and introduce oxygen into the cavity. Remember, the bacteria causing seedy toe are anaerobic. They cannot survive in the presence of oxygen. Exposing the cavity to air is step 1.

Note: we DO NOT recommend “stuffing” the hoof wall with any cotton based products. Cotton absorbs moisture and debris and begins to rot in warm moist environments within weeks - effectively feeding the hoof wall invasion you are trying to eliminate.  Resection is the preferred approach by experienced qualified professionals.

While your farrier or hoof care professional handles the physical debridement and resection of affected hoof wall, good hoof hygiene between appointments is also important.

Deep hoof wall separations can be difficult to clean thoroughly with normal picking alone. Soaking allows water and cleansing solution to reach further into accessible hoof wall crevices and separated areas, helping remove accumulated dirt and debris while you wait for your hoof care professional to assess and manage the hoof.

This is where Hoof Mate® Soaking Tablets can be a useful addition to your hoof hygiene routine.

Hoof Mate® tablets dissolve in water to create a convenient hoof soaking solution for thorough whole-hoof cleansing. Soaking can be particularly useful where hoof wall separation creates deeper areas that are difficult to reach with a hoof pick or surface cleaning alone.

It is not a substitute for appropriate trimming, resection or assessment by your farrier or hoof care professional. Instead, think of soaking as another way to keep the hoof thoroughly cleaned between professional visits.

How to soak the hoof

• Dissolve 1–2 Hoof Mate® tablets in approximately 1 litre of potable water. Each tablet makes 500 ml of soaking solution.
• Soak the hoof for 15–20 minutes.
• Use as part of your regular hoof hygiene routine between farrier or hoof care appointments.
• A Curved Tip Syringe can also be used to direct the prepared solution into accessible hoof wall crevices and separated areas.
• Allow the hoof to dry after soaking.

Your hoof care professional can advise how frequently soaking is appropriate for the individual hoof and management plan.

Keep the prepared area clean and protected

Once loose or compromised hoof wall has been appropriately managed by your hoof care professional, the resulting recess can collect dirt, debris and moisture as the horse moves around.

This is where Beeswax Blue Balls® can be useful.

Beeswax Blue Balls® are a mouldable cosmetic hoof wax designed for use in prepared hoof wall recesses, crevices and separated hoof wall.

The wax can be smeared across the prepared area to:

• Help keep dirt and debris out
• Cover the prepared hoof wall recess
• Help reduce everyday exposure to dirt and moisture
• Stay where applied between regular hoof checks

To use, soften a small amount between your fingers, pull off only what you need and smear a thin layer across the prepared recess.

The wax moulds easily to the shape of the hoof wall area without adhesives. Replace as required during your normal hoof care routine.

Do not tightly fill or overpack deep hoof wall spaces. Beeswax Blue Balls® are designed to be smeared across the prepared area rather than firmly packed into the hoof.

Tip: During your regular pick-out, the Curved Tip Syringe can also be used with Hoof Spray to help direct the spray into accessible hoof wall crevices before reapplying the wax if required.

As the hoof wall grows down, continue regular professional hoof care and maintain a consistent cleaning and hoof hygiene routine between appointments.

Keep conditions clean and dry

Environmental management is non-negotiable during seedy toe treatment.

• Move the horse off wet, boggy ground where possible during treatment
• Provide a dry standing area: rubber mats, packed gravel, or a dry yard are ideal
• Pick out and spray the affected foot when replacing the Beeswax Blue Balls®
• Use Hoof Spray with Kunzea Oil as part of your daily pick-out routine to cleanse and deodorise the hoof and surrounding crevices
• Avoid exposing the hoof to deep mud, manure, or prolonged periods in water

Monitor and maintain shortened trim intervals

Your farrier will advise on follow-up timing. During active management, this may be every 2–4 weeks rather than the usual 5–6 weeks. More frequent trimming allows your hoof care professional to:

• Monitor how far the infection has spread (or improved)
• Remove any new compromised hoof wall before it becomes a larger cavity
• Reassess whether the hoof wall is growing out clean above the resected area
• Adjust the trim to reduce mechanical forces on the white line

Recovery time depends on the extent of the infection. Mild cases caught early may resolve within one or two trim cycles. Significant resections require the hoof wall to grow out completely, which takes up to 12 months in adult horses. Patience and consistency are essential.

Most cases of seedy toe are managed successfully by a farrier or barefoot trimmer in partnership with the horse owner. However, call your vet if:

• Your horse is lame or reluctant to weight-bear on the affected foot
• The infection appears to have spread to the coronary band or is oozing from the hairline
• There is heat, swelling, or discharge from the lower leg
• The cavity is very large and your trimmer suspects coffin bone involvement
• The horse has a history of laminitis and seedy toe is recurring frequently

In some cases, radiographs (x-rays) may be needed to assess whether the coffin bone has been affected. This is rare but important to rule out in horses with significant rotation history or larger ongoing, unresolved infections.

Once you've been through a seedy toe episode, you're probably not keen to go through it again. The good news is that with the right routine, recurrence is largely preventable.

1. Keep to a regular trim schedule

This is the single most important prevention step. Ideally every 4–5 weeks, and no longer than 6 weeks. Long toes are the biggest mechanical contributor to white line stress.

2. Daily hoof pick-out and inspection

Every time you pick your horse's feet, run your eye along the white line. Any dark staining, widening, or soft spots are worth monitoring. Catching a small issue at the trim is infinitely better than treating a large cavity.

3. Maintain daily hoof hygiene

A quick spray with Hoof Spray with Kunzea Oil as part of your daily pick-out routine helps keep the hoof clean and maintains a firmer hoof surface. Kunzea oil is a native Australian botanical chosen for its conditioning qualities and refreshing aroma. 

4. Keep cavities packed

If your horse has had a resection and is growing out new hoof wall, keep the exposed area sealed with Beeswax Blue Balls® between farrier visits. This is especially important during wet weather when debris and mud can repack the space.

5. Address laminitis risk proactively

If your horse or pony is prone to laminitis, particularly during spring and autumn flushes on lush pasture, manage their diet and grazing accordingly. Every laminitis episode risks further white line damage and long-term hoof health. Work with your vet and farrier on an ongoing management plan.  Read more on laminitis here

6. Improve paddock drainage and footing

If possible, give horses access to dry, firm ground, especially during wet seasons. Standing in deep mud for extended periods is one of the most consistent contributing factors to white line deterioration.

7. Consider nutritional support

Talk to your vet or an equine nutritionist about whether your horse's diet supports strong hoof horn quality. Biotin, zinc, methionine, and copper all play roles in hoof wall integrity.

8. Use periodic soaks preventatively

Particularly through wet winter months, incorporating a monthly Hoof Mate® soak can help manage any hard-to-reach areas before infection takes hold. Think of it as a maintenance wash for the inside of the hoof.

1. O'Grady, S. E. & Burns, T. D. (2019) — White Line Disease: A Review (1998–2018)

Read the professional review

Published in Equine Veterinary Education. Reviews white line disease, hoof wall separation, professional resection, hoof mechanics and management of extensive defects.

2. O'Grady, S. E. (2006) — Management of White Line Disease

Read the AAEP conference paper

Originally published in the American Association of Equine Practitioners conference proceedings. Discusses professional removal of compromised hoof wall, appropriate farriery and monitoring during hoof wall regrowth.

3. Merck Veterinary Manual — Disorders of the Foot in Horses

Read the veterinary reference

Includes a section on white line disease (seedy toe), covering hoof wall separation, contributing factors, clinical signs and professional management.