Abscesses
Foals can develop quite severe foot abscessation, more commonly in the hind limbs.
Most cases are believed to result from subsolar haematoma formation during the first
few days of life on the soft soles. These are typically very painful, resulting in nonweight-bearing lameness. Paring away defective sole to create drainage of pus from
the normally extensive subsolar cavity is curative. There is often a small sequestrum
of P3 involved that will either be expelled from the drainage hole or in some
instances will have to be curetted out surgically. Protection of the new soft
developing sole by gradual removal of the old sole over time and a light foot bandage
is important to prevent recurrence.
The proximal sesamoid bones
There is a high incidence of PSB fracture in foals which usually results from
excessive strain across the suspensory apparatus, caused by keeping up with the
mare running or excessive boisterous behaviour in the paddock. More commonly
they are apical or basilar fractures, but all configurations including mid-body, sagittal
and comminuted fractures may occur. They may be uniaxial, bilateral or biaxial with
a worsening prognosis in that order.
Lameness resulting from these fractures ranges from barely detectable with a little
pain on the turn to non-weight-bearing. Severity of lameness usually corresponds to
the fracture configuration and disruption of the suspensory apparatus. Clinically the
fetlock region is normally mildly swollen, with or without fetlock joint effusion. Most
PSB fractures respond very well to conservative management of stable confinement
for four to eight weeks and anti-inflammatories with anti-ulcer medication initially.
Although initial bandaging may help with acute swelling, prolonged support
bandages or splinting are contraindicated to prevent flexor laxity. Gradual turn out
into larger paddocks after the initial confined period is recommended to prevent reinjury.
Prognosis for most fractures is fair to good for athletic function; sometimes the
fragments unite in an elongated fashion to form a megasesamoid which may have a
negative impact on sales radiographs. Biaxial mid-body fractures result in complete
failure of the suspensory apparatus and salvage procedures for stud value, such as
wiring the PSBs or fetlock arthrodesis, are options.
Physeal fractures
Physeal fractures are relatively common in foals due to the discrepancy in strength
between the stronger diaphyseal bone and weaker physeal bone. Clinical
presentations vary considerably and correlate to the extent of displacement and
stability of the fracture. Foals may be weight bearing on non-displaced stable
fractures with mild lameness and pain on palpation or manipulation being the only
symptoms to three-legged lame with angular deviations of the limb distal to a
displaced fracture.
Proceedings
of
the
South
African
Equine
Veterinary
Association
Congress
2016
234