Ultrasonographic and magnetic resonance imaging diagnosis of an oropharyngeal wood penetrating injury in a dog.

A 5 yr old female intact English setter with a 17 day history of a penetrating oropharyngeal wound was referred for cervical swelling and pain. Physical examination revealed swelling at the left lateral aspect of the cranial cervical region. Pain was elicited upon flexion, extension, and leftward movement of the neck. Neurologic deficits were not identified. Cervical ultrasonography showed a 0.4 cm × 2.3 cm linear, hyperechoic structure in the soft tissues ventrolateral to the first (C1) and second (C2) cervical vertebrae. MRI demonstrated a linear structure 2 cm in length adjacent to the cranial aspect of C2. The foreign material was isointense to hyperintense on precontrast T1-weighted images, isointense on postcontrast T1-weighted images, and hypointense on T2-weighted images relative to adjacent muscle. Abnormalities within the spinal canal were not identified. Upon surgical exploration, a reed foreign body was identified deep to the serratus ventralis muscle. The patient was normal on follow-up evaluations 4 wk postsurgically.

Efficacy of immobilization of the tarsal joint to alleviate strain on the common calcaneal tendon in dogs.

OBJECTIVE: To measure strain in the common calcaneal tendon during trotting in dogs and to compare strain before and after immobilization of the tarsal joint. ANIMALS: 6 dogs. PROCEDURES: A microminiature strain gauge was surgically implanted on the tendinous portion of the gastrocnemius muscle. Surface electromyography (EMG) values, percentage strain, and ground reaction forces were measured before and after immobilization. Peak vertical force; vertical impulse; initial, maximum, and final strain; and peak-to-peak EMG amplitude were recorded. Data were analyzed by use of a repeated-measures ANOVA and paired t tests. RESULTS: Timing of strain data correlated closely with foot strike of the hind limb and EMG activity in all dogs. Maximum tendon strain was simultaneous with peak vertical force. Continued muscle contraction was evident after immobilization. There was no significant difference in maximum strain after immobilization, compared with maximum strain during normal motion. Minimum strain, both at the beginning and end of the strain curve, was significantly decreased for the immobilized state, compared with results for nonimmobilized joints. CONCLUSIONS AND CLINICAL RELEVANCE: Immobilization of the tarsal joint did not eliminate calcaneal tendon strain during weight bearing in dogs. Decreased isometric muscle contraction during the swing phase of the gait could account for smaller minimum strain in immobilized joints. Immobilization is frequently applied after Achilles tendon rupture to alleviate strain and force on the sutured repair, with possible complications because of the immobilization method. Consideration of these findings could be important in adjusting current treatment recommendations.