Objective—To determine the electrophysiological changes in dogs with peripheral nerve sheath tumors (PNSTs), evaluate the prevalence of these changes, assess the correlation between spontaneous activity in epaxial muscles and proximal invasion by the tumor, and evaluate whether knowledge of electrophysiological changes could be helpful in the imaging diagnosis via CT or MRI.
Design—Retrospective case series.
Animals—51 dogs with a histologic (n = 18) or a suspected (33) diagnosis of PNST.
Procedures—Clinical, postmortem, and histologic reports and details of electrodiagnostic procedures and CT or MRI reports were studied. Twenty-four CT and 6 MRI reports for dogs with PNSTs were reviewed by a single observer blinded to the diagnosis.
Results—Only 2 of the 51 dogs had no electrophysiological changes. The most commonly affected muscles were those innervated by the radial, ulnar, median, tibial-sciatic, and peroneal nerves. Abnormal spontaneous epaxial muscle activity was significantly more frequent in the group with foraminal or spinal invasion by the tumors. Knowledge of the electrophysiological changes increased diagnostic accuracy of CT.
Conclusions and Clinical Relevance—Results suggested that electrophysiological studies may be sensitive for the detection of PNST and helpful in the imaging diagnosis. Epaxial electromyographic abnormalities appeared to be predictive for intervertebral or vertebral canal invasion by PNSTs in dogs.
Objective—To quantify radial and longitudinal left
ventricular free wall (LVFW) velocities in dogs during
the preclinical phase of Golden Retriever muscular
dystrophy (GRMD)-associated cardiomyopathy by use
of tissue Doppler imaging (TDI).
Animals—9 dogs with GRMD and 6 healthy control
Procedure—All dogs (< 3 years old) were examined
via conventional echocardiography and 2-dimensional
color TDI. Myocardial velocities in the LVFW were
recorded from right parasternal ventricular short-axis
(radial motion) and left apical 4-chamber (longitudinal
motion) views. Cardiac assessments via TDI included
maximal systolic and early and late diastolic LVFW
velocities in the endocardial and epicardial layers (for
radial motion) and in the basal and apical segments
(for longitudinal motion).
Results—No notable ventricular dilatation or alteration
of inotropism was detected in dogs with GRMD
via conventional echocardiography. Compared with
healthy dogs, endocardial velocities were significantly
decreased in dogs with GRMD, resulting in marked
decreases in radial myocardial velocity gradients during
systole and early and late diastole. Similarly, basal
and apical velocities were significantly decreased in
systole and the former also in early diastole, resulting
in significant decreases in the 2 corresponding longitudinal
myocardial velocity gradients. The radial epicardial
and longitudinal late diastolic velocities were
comparable in the 2 groups.
Conclusions and Clinical Relevance—Results indicated
that GRMD-associated cardiomyopathy in dogs
is associated with early marked dysfunction of both
radial and longitudinal LVFW motions. These combined
regional myocardial abnormalities might be useful
criteria for detection of dilated cardiomyopathy at
the preclinical stage of the disease in dogs. (Am J Vet