Page 137 - Canine Lameness

8.5 Lameness valuation and Interpreting the ffect of iagnostic oint nesthesia 109

Perform DJA
using sedation Walk patient
Patient
Moderate-high does not Protocol B for five minutes
tolerate
grade lameness -agonist continuously
thought to be
Assess change
Assess change
joint related DJA in lameness after in lameness after
indicated? two minutes No five minutes
Perform DJA Assess
using sedation change in At least 20% At least 20%
lameness
Protocol A after seven improvement in improvement in
minutes lameness? lameness?
Yes No
Yes
Assess
Joint IS source of At least 20% change in Assess change in
lameness until 30
lameness improvement in lameness minutes after
every five
Yes lameness? minutes injection
Positive
response No
False negative Negative
response 10% of cases response
Joint is NOT
Consider: source of lameness
• Was DJA performed 90% of cases
correctly?
• Was DJA protocol True negative
followed?
Perform additional response
diagnostics of the
instilled joints

Perform X-rays,
CT, MRI, and Perform X-rays, CT, Perform additional
arthroscopy MRI, arthroscopy, diagnostics of
scintigraphy, and other joints
DJA of other joints
Specific
diagnosis

Figure 8.1 Decision tree for determining DJA protocol and interpretation of lameness assessment.

Both protocols outlined above were found to have the potential to influence lameness and
thereby DJA interpretation. Van Vynckt et al. (2011) evaluated the influence of sedation on dogs
with lameness (without performing DJA) and found that most dogs (72% for protocol A and 80%
for protocol B) experienced no change in lameness due to sedation. However, sedation lead to a
worsening of lameness by 1–2 grades in up to 20% of lame dogs (20% for protocol A and 12% for
protocol B) and an improvement by 1 grade in 8% (for both groups). In general, lameness may
become more obvious in anxious dogs (since the sedation results in them relaxing and being less
distracted by the unfamiliar environment) while the pain modulation associated with the sedation
may improve the lameness in less anxious dogs. Based on these findings, it is recommended that a
positive response to DJA be interpreted only when lameness improves by two or more grades
(using an 11‐point scale).