Page 1388 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

The foal 1363

VetBooks.ir Fig. 14.26 A foal with 14.26 14.27 14.28
distension of the right
intercarpal joint due to
synovial sepsis (S type).

Fig. 14.27
Dorsopalmar
radiograph of the distal
limb of a 4-week-old
foal with septic physitis
of the lateral distal
third metatarsal bone
(P type).

Fig. 14.28 An
8-week-old foal with
P type osteomyelitis
affecting the right stifle
with obvious swelling
on the lateral aspect.

soft-tissue swelling associated with a joint epiphy- differential WBC counts and total protein analy-
sis or physis (Fig. 14.28). Some joints that may sis. Synovial fluid and blood culture and sensitiv-
be involved are not always easily palpable (e.g. the ity testing are important, but false-negative results
shoulder or hip joint), and therefore all joints should are often obtained. Any material retrieved from
be carefully examined. Skin surfaces should be eval- bone lesions should also be cultured and examined
uated for signs of trauma or a penetrating wound. cytologically. Radiographs of any suspicious joints
Pain and restricted movement of an affected joint, or or physeal regions are helpful in differentiating
pain on palpation of the physis, should be evaluated. the types of disease, directing specific therapy and
A thorough clinical examination is required to iden- clarifying the prognosis. In chronic cases they help
tify foci of infection as well as systemic or multifocal detect severe damage such as osteoarthritis or osteo-
disease. myelitis. Radiographs are especially helpful in cases
involving bone infection (Fig. 14.27). False-negative
Differential diagnosis radiographic findings do occur in early cases and
Other causes of lameness of both infectious and non- repeat radiographs should be considered 3–10 days
infectious aetiologies (i.e. fractures, foot abscess, later when this is suspected. Ultrasonographic
traumatic injuries); non-septic joint disease; hae- examination of joints can yield useful information,
moarthrosis. In a young foal presenting with two particularly where there is considerable periarticu-
or more of the above clinical signs, the case should lar swelling. In both bone and synovial sepsis, blood
be treated as a potential infection until proven samples usually indicate signs of infection. The total
otherwise. WBC count is usually increased, with a neutrophilia,
marked increase in SAA and increased fibrinogen
Diagnosis concentrations. In all cases of septic arthritis/
Diagnosis is confirmed by analysis of synovial fluid osteomyelitis it is essential to check for other disease
obtained by aseptic synoviocentesis. The sample and a focus of infection, including ultrasound evalu-
should be subjected to visual examination, total and ation of the umbilical remnants.