DIAGNOSING, MANAGING, AND RESOLVING LAMENESS IN HORSES
Fig. 4. A, Probe placement, sagittal view. B, Sagittal paired images left and right just off midline at the level of T18 with 7.5 MHz linear transducer. C, Sagittal paired images left and right just off midline at the level of T18 with 3.5 MHz macroconvex transducer. (MM, multifidus muscle; MP, mammillary process.)
Most of these horses were sent to evaluation after absence of x-ray findings, and for some of them neg- ative bone scintigraphy, when realized. For diag- nostic purposes, most of them (15/22) underwent a local block of the spastic area and responded well. Unfortunately, the next day these horses tend to worsen significantly. A careful evaluation with ultrasonography was
done to evaluate the soft tissues involved with this abnormal region of the back. Two different por-
296 2019 Vol. 65 AAEP PROCEEDINGS
table devices (Figs. 4A and B) were used for this study with a linear probe (7.5 Mhz) offering a moderate penetration but a good detail of the mul- tifidus structure, and a large convex probe (2.5 MHz) giving opportunity to go deeper with lesser details, but also being able to evaluate larger horses and the caudal insertion of the MMs on the vertebral body. This paper will first review the technique of evaluation of the MMs and then dis- cuss its abnormal findings found in 22 horses.
