Objective—To monitor the effect of focused extracorporeal
shock wave therapy (ESWT) on bone and
bone-tendon junction of horses without lameness by
use of nuclear scintigraphy and thermography.
Animals—6 warmblood horses without lameness.
Procedure—The origin of the suspensory ligament at
the metacarpus (OSL-MC) and the fourth metatarsal
bone were treated at 2 time points (days 0 and 16)
with 2,000 shocks applied by a focused ESWT device
at an energy flux density of 0.15 mJ/mm2. One forelimb
and 1 hind limb were treated, and the contralateral
limbs served as controls. To document the effect
of focused ESWT, nuclear scintigraphy was performed
on days -1, 3, 16 (before second ESWT), and
19. Thermography was performed on days -1, 0 (1
hour after first ESWT), 1, 3, 8, 16 (twice; before and 1
hour after second ESWT), and 19. On days 3, 16 (first
scans), and 19, thermography was performed before
Results—Scintigraphically, significant variations in
radiopharmaceutical activity at the OSL-MC were
detected in treatment and control limbs. No significant
differences, however, in mean temperature or
radiopharmaceutical activity could be detected by use
of thermography or nuclear scintigraphy, respectively,
between the treatment and control limbs at any time
point in response to ESWT.
Conclusions and Clinical Relevance—After 2 treatments
of focused ESWT, no physiologic effect on the
studied structures could be demonstrated by use of
nuclear scintigraphy or thermography. Results of this
study indicate that at currently used ESWT settings,
no damage to the bone or bone-tendon junction
should occur. (Am J Vet Res 2005;66:1836–1842)
Objective—To determine via histologic examination and scintigraphy the effect of focused extracorporeal shock wave therapy (ESWT) on normal bone and the bone-ligament interface in horses.
Animals—6 horses without lameness.
Procedure—Origins of the suspensory ligament at the metacarpus (35-mm probe depth) and fourth metatarsal bone (5-mm probe depth) were treated twice (days 0 and 16) with 2,000 shocks (energy flux density, 0.15 mJ/mm2). One forelimb and 1 hind limb were randomly treated, and the contralateral limbs served as nontreated controls. Bone scans were performed on days −1 (before ESWT), 3, 16, and 19. Histomorphologic studies of control and treated tissues were performed on day 30.
Results—ESWT significantly increased the number of osteoblasts but caused no damage to associated soft tissue structures and did not induce cortical microfractures. A significant correlation between osteoblast numbers and radiopharmaceutical uptake was noticed on lateral views of the hind limb on days 3 and 16 and on caudal views of the forelimb on day 3.
Conclusions and Clinical Relevance—Results suggested that ESWT has the potential to increase osteoblast numbers in horses. The correlation between increased osteoblast numbers and radio-pharmaceutical uptake 3 days and 16 days after the first ESWT suggested that stimulation of osteogenesis occurred soon after ESWT. No damage to bone or the bone-ligament interface should occur at the settings used in this study, and ESWT can therefore be administered safely in horses.
Objective—To compare anesthesia recovery quality after racemic (R-/S-) or S-ketamine infusions during isoflurane anesthesia in horses.
Animals—10 horses undergoing arthroscopy.
Procedures—After administration of xylazine for sedation, horses (n = 5/group) received R-/S-ketamine (2.2 mg/kg) or S-ketamine (1.1 mg/kg), IV, for anesthesia induction. Anesthesia was maintained with isoflurane in oxygen and R-/S-ketamine (1 mg/kg/h) or S-ketamine (0.5 mg/kg/h). Heart rate, invasive mean arterial pressure, and end-tidal isoflurane concentration were recorded before and during surgical stimulation. Arterial blood gases were evaluated every 30 minutes. Arterial ketamine and norketamine enantiomer plasma concentrations were quantified at 60 and 120 minutes. After surgery, horses were kept in a padded recovery box, sedated with xylazine, and video-recorded for evaluation of recovery quality by use of a visual analogue scale (VAS) and a numeric rating scale.
Results—Horses in the S-ketamine group had better numeric rating scale and VAS values than those in the R-/S-ketamine group. In the R-/S-ketamine group, duration of infusion was positively correlated with VAS value. Both groups had significant increases in heart rate and mean arterial pressure during surgical stimulation; values in the R-/S-ketamine group were significantly higher than those of the S-ketamine group. Horses in the R-/S-ketamine group required slightly higher end-tidal isoflurane concentration to maintain a surgical plane of anesthesia. Moderate respiratory acidosis and reduced oxygenation were evident. The R-norketamine concentrations were significantly lower than S-norketamine concentrations in the R-/S-ketamine group.
Conclusions and Clinical Relevance—Compared with R-/S-ketamine, anesthesia recovery was better with S-ketamine infusions in horses.