Thrush is a common change in the equine hoof. The soft horn of the frog, especially in the sulci, is broken down by microorganisms. This article describes how it develops, how it presents and what hoof hygiene involves.
Development and risk factors
The frog is particularly vulnerable to prolonged moisture and soiling. Risk factors include:
- poorly managed, damp bedding with faeces and urine
- infrequent or inadequate hoof picking
- deep, narrow sulci and unfavourable hoof conformation
- little exercise and inadequate hoof trimming
Under these conditions the horn softens and becomes easier for microorganisms to break down.
Clinical findings
- foul smell when the hoof is picked out
- greasy, dark changes in the frog horn
- cavities in the frog and horn that is coming away
With superficial changes, horses are usually sound. If the changes extend deeply, the underlying tissue may be involved. Pain and lameness can then occur, and veterinary examination is needed.
Differential diagnoses
Differentials include canker, white line disease and hoof abscesses, among others. For persistent, deep or proliferative changes, the veterinarian should make the diagnosis.
Management
The key is to remove the causes and keep up consistent hoof hygiene:
- daily hoof picking and inspection
- clean, dry bedding and regular mucking out
- regular, professional hoof trimming
- sufficient exercise
- for deep or painful changes, veterinary assessment and a decision on further measures