Objective—To compare the ability of 2 partial IV anesthesia (PIVA) techniques to maintain anesthesia, compared with isoflurane alone, in horses.
Procedures—Client-owned horses requiring general anesthesia for a variety of procedures of at least 1 hour's duration were randomly allocated to 3 groups (n = 15/group) that differed for the maintenance protocol. Anesthesia was maintained with isoflurane with a starting end-tidal isoflurane concentration of 1.3% (isoflurane group) or a concentration of 1% supplemented with an adjustable continuous infusion of guaifenesin-ketamine (IGK group) or romifidine-ketamine (IRK group). A predefined scoring system was used to assess anesthetic depth and to adjust anesthetic delivery. The need for rescue anesthetics and recovery quality were compared.
Results—A mean ± SD end-tidal isoflurane concentration of 1.36 ± 0.16% was necessary to maintain a surgical plane of anesthesia in the isoflurane group. Mean infusion rates of 5.0 ± 1.3 μL/kg/min and 5.1 ± 0.8 μL/kg/min were necessary to maintain a surgical plane of anesthesia in the IRK and IGK groups, respectively. A lower need for ketamine as a rescue anesthetic was observed in the IGK group, compared with the isoflurane group. Higher blood pressure and lower heart rates were found at selected time points for the IRK group, compared with the IGK and isoflurane groups.
Conclusions and Clinical Relevance—Both PIVA protocols were satisfactory to maintain smooth and stable surgical anesthesia in horses. The present study supports previous findings in which PIVA has isoflurane-sparing effects. Furthermore, PIVA did not impair recovery quality.
OBJECTIVE To determine the influence of various neck positions on cervical vertebral radiographic measurements in horses.
ANIMALS 18 client-owned horses examined for lameness but free of cervical disease.
PROCEDURES Laterolateral radiographs of the cervical vertebrae from C1 through T1 were acquired for each horse in 3 neck positions (low, neutral, and high). Minimum sagittal diameter, intravertebral sagittal diameter (intra-VSD) ratio, inter-VSD ratio, length of the articular processes joint ratio, vertebral alignment angle, and vertebral fossa angle were measured at each segment in each neck position. Values for the high and low positions were compared with those for the neutral position.
RESULTS No significant differences from neutral position values were identified for minimum sagittal diameter, intra-VSD ratio, and vertebral fossa angle as measured in low and high neck positions. Compared with results in the neutral position, the high position resulted in a greater vertebral alignment angle at C3–4 and inter-VSD ratio at C4–5 and a lower length of the articular processes joint ratio at C2–3, C3–4, and C4–5; the low position resulted in a lower vertebral alignment angle at C4–5. However, all observed differences were small.
CONCLUSIONS AND CLINICAL RELEVANCE Neck position influenced some radiographic measurements of the cervical vertebrae in horses free of cervical disease. However, because several of these measurements were not or were only minimally affected by neck position, some latitude in neck position may be possible without concern about substantially affecting radiographic measurements in this region.
CASE DESCRIPTION 8 horses (5 geldings and 3 mares) were evaluated for laparoscopic closure of the nephrosplenic space following a history of recurrent left dorsal displacement of the large colon.
CLINICAL FINDINGS All horses underwent a physical examination and routine clinicopathologic testing. Transrectal palpation and transabdominal ultrasonography were performed to exclude the presence of organs in the left paralumbar region.
TREATMENT AND OUTCOME A left flank laparoscopic approach with the horses standing was used. A continuous suture was placed in a craniocaudal direction between the renal and splenic capsules with unidirectional barbed suture material. This allowed obliteration of the nephrosplenic space without the need for knots to secure the leading and terminal ends of the suture line. In all horses, transrectal palpation was performed 2 months after surgery; at this time, closure of the caudal part of the nephrosplenic space was evident. In 2 horses, follow-up laparoscopy was performed, and complete closure of the nephrosplenic space was confirmed. Telephone follow-up revealed that none of the horses had any signs of recurrent left dorsal displacement of the large colon.
CLINICAL RELEVANCE Results suggested that laparoscopic nephrosplenic space closure with unidirectional barbed suture material could be considered as an option for prevention of left dorsal displacement of the large colon in horses. In the horses of this report, barbed suture material allowed secure ablation of the nephrosplenic space and eliminated the need for intracorporeal knot tying.