Thrush in horses: how to recognise it, care for it daily and prevent it
A dark, foul-smelling frog signals that action is needed: consistent picking out, a dry environment and a daily care routine are essential
A person picking out a horse's hoof and cleaning the frog sulci to prevent thrush. · AI-generated
This article was created with the help of AI.
How to recognise thrush
In everyday life you will recognise thrush above all by dark, greasy decomposition products with a sharp, putrid smell in the frog sulci. The smell is the most reliable early sign. During a routine check, the tip of the hoof pick reaches deep into the central or lateral sulcus, while the frog horn often feels soft, cracked and ragged.
The change typically begins superficially in the area of the central sulcus (sulcus centralis) and, without consistent care, spreads to the lateral sulci and the horned surface of the frog. Daily cleaning reveals that the horn loses its firm structure in the affected areas. The horned surface of the frog then appears rough and cracked, and decomposition products collect in the crevices.
When pressure is applied to the deeper layers, sensitive horses respond with avoidance behaviour. As long as the change remains within the horn, thrush usually proceeds without lameness: lameness typically only appears once the condition has reached the sensitive laminae. Bleeding often shows when the frog tissue is touched carelessly with the hoof pick.
- A typical putrid smell when picking out the hoof
- Dark, greasy deposits in the frog sulci
- Excessive depth of the central and lateral sulci
- Soft, ragged or cracked frog horn
- Sensitivity to pressure when cleaning the sulci deeply
How common thrush really is
Thrush is one of the most frequently documented hoof changes in everyday equine practice. A large field study shows that almost half of the horses examined were affected. Thrush is therefore an everyday care topic, not a marginal finding.
In einer groß angelegten Querschnittsstudie an 942 zufällig ausgewählten Pferden in den Niederlanden stellten 21 zertifizierte Hufschmiede bei 45,0 % der Tiere Strahlfäule fest. Die Beurteilung erfolgte im Rahmen der regulären Hufbearbeitung, und Strahlfäule war dabei die häufigste der zwölf erfassten Hufveränderungen.
Diese Zahl beschreibt das Vorkommen in der untersuchten Gesamtpopulation von 942 Pferden. Dieselbe Studie weist nasse Stallböden, dauerhafte Stallhaltung und schlechte Hornqualität als Risikofaktoren aus. Sie bedeutet aber nicht, dass Strahlfäule ausschließlich eine Folge nasser Haltung ist. Die Erkrankung tritt auch bei Pferden auf, die angemessen versorgt werden und in sauberer, trockener Umgebung stehen.
| Untersuchter Parameter | Studienergebnis (Holzhauer et al. 2017) |
|---|---|
| Stichprobengröße (n) | 942 zufällig ausgewählte Pferde |
| Untersuchende Personen | 21 zertifizierte Hufschmiede |
| Nachgewiesene Prävalenz | 45,0 % der 942 untersuchten Pferde |
Was Strahlfäule begünstigt
Strahlfäule entsteht vor allem durch ein feuchtes, sauerstoffarmes Milieu in den Strahlfurchen. Festgetretenes Material aus Einstreu, Mist und Erde schließt die Furchen luftdicht ab. In diesem feuchten Milieu vermehren sich anaerobe Bakterien bevorzugt. Haltungsfaktoren wie nasse Böden, zu seltene Hufreinigung, lange Schmiedeintervalle und Bewegungsmangel verstärken diesen Prozess erheblich.
Eine mikrobiologische Untersuchung an 28 Hufproben von 16 Pferden bringt das anaerobe Bakterium Fusobacterium necrophorum mit Strahlfäule in Verbindung. Diese Bakterien benötigen für ihr Wachstum ein sauerstofffreies Klima, wie es unter kompakten, feuchten Schmutzpfropfen in tiefen Strahlfurchen entsteht. Als begünstigende Faktoren gelten seltenes Auskratzen der Hufe, unregelmäßige Hufbearbeitung und längeres Stehen in feuchter, unhygienischer Umgebung.
Dass ausgerechnet das Strahlhorn besonders anfällig für feuchte Zersetzungsprozesse ist, liegt an seiner spezifischen Materialbeschaffenheit. In 177 Zug- und Biegeversuchen an 110 Hornproben von sechs Warmblutpferden lag der physiologische Feuchtigkeitsgehalt der Strahlproben im Mittel bei 34,6 %, der der Sohlenproben bei 31,5 % und der der Wandproben bei 22,7 %. In derselben Untersuchung lag das Elastizitätsmodul des Strahlhorns mit 9,9 N/mm² weit unter dem des Sohlenhorns mit 230 N/mm². Dieser hohe Eigenfeuchtigkeitsgehalt macht den Strahl elastisch, bei dauerhafter äußerer Nässe aber auch besonders nachgiebig.
| Begünstigender Faktor | Mechanismus im Huf | Anpassung in der Haltung & Pflege |
|---|---|---|
| Nasse Einstreu / Matsch | Verweicht das Horn und fördert Feuchtigkeitsstau | Trockenes Einstreumanagement, saubere Paddockbereiche |
| Eingeschlossener Schmutz | Erzeugt ein sauerstofffreies (anaerobes) Milieu | Tägliches gründliches Auskratzen und Ausbürsten |
| Lange Bearbeitungsintervalle | Tiefe, enge Furchen begünstigen Ablagerungen | Regelmäßige Hufbearbeitung alle 6 bis 8 Wochen |
| Bewegungsmangel | Reduzierter Hufmechanismus vermindert Selbstreinigung | Tägliche freie Bewegung und gezieltes Bewegungstraining |
Die tägliche Hufroutine
Eine konsequente Hufhygiene ist die wirksamste Grundlage zur Vorbeugung von Strahlfäule. Die offiziellen Leitlinien zur Beurteilung von Pferdehaltungen unter Tierschutzgesichtspunkten vom 9. Juni 2009 geben hierzu eine klare Orientierung vor. Das tägliche Reinigen, sachgemäße Auskratzen und Trocknen der Strahlfurchen schützt das empfindliche Horngefüge vor feuchtigkeitsbedingter Erweichung und unerwünschtem Luftabschluss.
Die Leitlinien zur Beurteilung von Pferdehaltungen unter Tierschutzgesichtspunkten halten fest, dass insbesondere vor und nach jeder Nutzung Sohle und Strahlfurchen gesäubert werden sollten. Durch diese einfache Routine bleibt kein Mist- oder Reitplatzrest über längere Zeit in den Furchen liegen und bildet dort ein sauerstoffarmes Milieu. Zum Gesamtablauf gehören auch feste Bearbeitungsintervalle durch Hufschmied oder Hufpfleger: Das Beschlagintervall beträgt laut Leitlinien in der Regel 6 bis 8 Wochen.
- Huf sicher aufnehmen und kontrollieren: Prüfen Sie Sohle und Strahl visuell auf Unregelmäßigkeiten, Spalten oder Feuchtigkeitsansammlungen.
- Auskratzen von der Trachte zur Zehe hin: Führen Sie den Hufkratzer stets von hinten nach vorne, um nicht versehentlich in die empfindliche Ballenregion oder tiefe Strahlspalten zu stoßen.
- Strahlfurchen gründlich ausbürsten: Entfernen Sie feine Erd- und Einstreureste mit einer festen Hufbürste aus den seitlichen und der mittleren Strahlfurche.
- Feuchtigkeit kontrollieren und abtrocknen: Wenn der Huf gewaschen wurde oder nasse Erde anhaftete, trocknen Sie den Strahl mit einem sauberen Tuch sorgfältig ab.
- Regelmäßigen Bearbeitungsrhythmus einhalten: Lassen Sie die Hufform im Abstand von 6 bis 8 Wochen fachgerecht überprüfen und korrigieren.
Home remedies fact-checked
Around the stable, numerous home remedies are recommended for frog care, from toothpaste to apple cider vinegar. A sober look at the scientific evidence shows, however, that for most of these methods no published proof exists. In addition, strongly drying or caustic substances carry the concrete risk of lasting damage to healthy horn and the adjacent skin tissue.
Toothpaste is occasionally smeared into the frog, because the surfactants or flavouring agents it contains are expected to have a drying effect. In the veterinary literature there are no scientific studies at all that examine or confirm the benefit of toothpaste on the horse's hoof. What is more, additives such as menthol or abrasive particles can irritate the fine tissue structures of the frog.
Apple cider vinegar is valued for its acidic pH. Specialist publications on its effectiveness against thrush are, however, entirely lacking. Aqueous vinegar solutions also introduce additional moisture into an already softened frog, which works against the goal of a dry environment.
Strongly acting substances such as highly concentrated iodine solutions do have drying properties, but they are not without risk. The Merck Veterinary Manual points out that when selecting topical agents, the depth of tissue involvement must be taken into account, as many agents can cause further damage to the germinal tissue through their caustic effect. Harsh drying also costs the frog horn its elasticity and encourages new cracks.
| Home remedy | Claimed effect | Scientific evidence | Possible risks to the hoof |
|---|---|---|---|
| Toothpaste | Drying, odour binding | No published studies available | Tissue irritation from abrasive particles and flavourings |
| Apple cider vinegar | Acidifying the pH environment | No evidence for use on the hoof | Introduces additional moisture into already softened horn |
| Iodine solution | Drying out of the clefts | No studies on use in thrush | Excessive drying, tissue irritation at high doses |
What frog care can achieve
Proper care of the frog focuses on supporting clean, dry horn in its natural protective function. Once mechanical dirt has been removed and the frog clefts have been dried, a thinly applied layer of care product on the surrounding horn protects against external moisture. Such a care layer complements the daily stable routine without impairing the natural horn structure.
For targeted hoof and skin care, equion® Hoof and Skin Gel offers a modern care formula. After cleansing, the gel is applied in an ultra-thin layer to the clean, dry horn around the frog. The frog clefts themselves remain open, clean and dry. Thanks to its low viscosity, the paraffin oil gel remains on the horn surface as a gentle protective layer and shields the frog horn from direct contact with wet bedding or stable moisture. This is where its real benefit lies: the gel matrix keeps the particles with their stored ions on the horn for as long as possible, while the ions gradually move out on contact with moisture.
A note on the technology: zinc and silver ions are stored in an inert carrier material. On contact with moisture from the surroundings, the ions are released in a controlled manner. Because the ions are already stored in their ionic form, no prior chemical reaction is required. The gel is intended solely for the hygienic care, cleansing and external protection of the hoof. It is not a medicine and, in cases of deep tissue changes, does not replace proper diagnosis and care by a vet or farrier.
Note: These explanations describe the properties of the ingredients and how the technology works. They are not statements about the healing or treatment of diseases.
- Thorough cleansing and complete drying of the frog clefts as the first prerequisite
- Applying an even care layer sparingly to the horned tissue
- Protecting the horn surface from external moisture
- Safety standards: developed to EU safety standards for human products and manufactured to ISO 22716
- A clear limitation: a pure care product to support daily hoof hygiene
When the farrier or vet should take over
Hygiene and care reach clear limits as soon as deeper hoof structures are affected. If the central frog cleft is split so deeply that the hoof pick disappears completely, if pressure triggers pain reactions or if blood becomes visible, professional help is essential. In these cases, the farrier or vet must immediately take over the assessment and care.
A clear warning sign is a pronounced pain response when the frog comes under pressure during routine picking out. If the change extends as far as the sensitive frog corium, hoof care alone is no longer sufficient. Affected frog horn must then be trimmed away professionally so that the deeper areas can be accessed and cared for at all.
If there is no clear improvement despite four weeks of consistently dry keeping and daily hoof cleaning, an expert should be brought in. Horses with deep central sulci and narrow heels are affected more often, and with such hoof shapes relapses are more likely. Hoof trimming should therefore be oriented to the individual circumstances of each hoof.
- The hoof pick tip sinking completely into deep pockets in the central sulcus of the frog
- Visible bleeding or weeping areas when picking out carefully
- Pain responses from the horse under light pressure on the frog
- Irregular gait, pain on turning or visible lameness
- No improvement after four weeks of consistent hoof hygiene and dry keeping
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equion Hoof & Skin Gel – 10 ml Sample
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All you need to know
In its early stages it often causes no pain. However, once the decay penetrates deeper and reaches sensitive structures such as the frog corium, the horse may show marked pressure sensitivity or lameness.
There is no scientific evidence for the effectiveness of toothpaste on the hoof. Its ingredients are not made for hoof horn and can further dry out and irritate tissue that is already damaged.
Without care, bacteria penetrate ever deeper into the horn. This can attack the frog corium, cause severe pain and lameness, and encourage serious chronic hoof problems.
Recovery depends on the depth of the damage and cannot be stated in general terms. If the condition remains unchanged despite consistently dry keeping and daily hoof hygiene, the hoof belongs in the hands of a farrier or vet.
Apple cider vinegar is often mentioned as a home remedy, but scientific proof of a positive effect is lacking. The acid it contains carries the risk of strongly attacking and drying out the soft frog horn.
A farrier or vet must be called in when the hoof pick disappears into deep crevices, the tissue bleeds, the horse goes lame, or despite four weeks of clean and dry care no visible improvement occurs.