Hoof abscess

Question 1

What is a hoof abscess?

Answer 1

▪Damage to the sole or white line of the hoof ▪Bacterial invasion and colonisation
▪Resulting in localised infection

Question 2

Predisposing factors

Answer 2

▪ Poor hoof quality
▪ Unhygienic environment
– dirty bedding
– turnout in wet conditions
▪ History of laminitis
– “seedy toe” / white line disease

Question 3

Clinical signs

Answer 3

▪Usually acute onset lameness
▪Lameness often severe ▪In rare cases, lameness
may be milder
▪Bounding digital pulse of the affected limb

Question 4

Diagnosis

Answer 4

▪ Localising the lame limb
▪ Presence of a digital pulse
▪ Examine the foot for anything obvious, such as penetrating injuries and foreign bodies
▪ Use of hoof testers
– Palpate around the hoof wall
– Percussion of different regions of the sole
– Horses are not always reactive

Question 5

Locating the lesion

Answer 5

• Remove the shoe
  – Start at the heel and pull towards the toe
• Remove the entire surface from the sole
• Explore the white line using a loop knife
• Look for any signs of abnormalities, such as black patches

Question 6

Relieving the infection

Answer 6

• Pare the area using hoof knives and nippers, if required
• The horse is likely to be reactive at this stage
• If required, consider sedation or a palmar digital nerve block to desensitise your pt
• Pare until pus is obtained
• Ensure a suitable drainage area is left, to prevent “refilling”

Question 7

Poultice

Answer 7

• Place a wet poultice over the foot
• Replace daily whilst the abscess drains
• After a day or two of clean poultices, replace with a dry poultice for 2 days, to allow the foot to harden.

Question 8

Other considerations

Answer 8

• Analgesia - NSAIDs (bute or flunixin)
• Does the horse have tetanus coverage?
  o If not, it requires a tetanus antitoxin injection
  o You can start the vaccination course at the same time but will require injection at a different site.
• Box rest
  o Excessive movement risks the infection tracking towards the coronary band which will prolong treatment time.

Question 9

What if I don’t obtain pus?

Answer 9

• Sometimes foot abscesses need a day to “brew”
• Place a poultice and revisit the next day
• Consider radiographs
  – locate the abscess
  – rule out other differentials

Question 10

Are antimicrobials required?

Answer 10

• For most foot abscesses no
  o Antibiotics can prevent a foot abscess from draining by encapsulating
• So when?
  o Soft tissue infiltration (e.g. secondary cellulitis or lymphangitis)
  o Readily draining abscess which you’re struggling to get on top of