One of the best ways to evaluate the internal structures of the foot is radiography. It's my opinion that this is one of the
most under-utilized tools in bovine lameness evaluations. It often is only performed when systemic anti-microbial therapy
alone has failed. Many deep infections require prompt surgical debridement along with anti-microbial therapy for any chance
of success. Unsuccessful antimicrobial treatment can waste valuable time and money, worsen the prognosis and remove culling
options due to exacerbated weight loss, increased debilitation and antimicrobial residue problems. If significant lesions
are recognized early through radiography, prognosis and treatment options can be discussed in a more timely manner. Remember
that visible radiographic lesions lag behind clinical signs by approximately two weeks. So in acute cases, repeat radiographs
might be necessary. However, an absence of radiographic lesions usually carries a better prognosis, so antimicrobial treatment
alone might be warranted. It is worth noting that the cruciate ligaments between the digits can ossify in older, heavy animals.
This will appear as smooth, sharp, slightly hook-shaped projections on the axial surface of the digits. Unless they are fractured,
or appear rough or lytic, they are considered incidental findings.
Septic arthritis of the coffin joint is a common cause of lameness in cattle. It often occurs as an extension of a Rusterholz
ulcer secondary to corkscrew claw in beef cattle. A key finding on physical exam is swelling of the heel region. Radiographs
might show widening of the joint space in early cases. A culture of joint fluid is the best way to choose appropriate antibiotic
therapy as an adjunct to other treatment options. An 18-gauge, 1-inch needle is inserted just proximal to the coronary band
at about a 45-degree angle, just lateral to the extensor process. Fluid should be placed in an EDTA tube for cytology, and
sterile media for culture. In my experience, this joint is difficult to tap in cattle, even with excellent restraint. Since
the coronary band area is usually swollen and inflamed, joint taps are commonly blood contaminated. Although this will alter
cytology results, it should not influence culture results.
Occasionally this technique can be helpful in finding pockets of infection, and possibly tendon sheath infections/ tendon
injuries. Ultrasonography also is being used to measure sole horn thickness in dairy cattle. Experience is required to interpret
some lesions. It is sometimes helpful to compare the effected limb with the normal limb when there is question about the significance
of a finding.