No abstract

Objective To determine the anaesthetic and systemic effects of dorsolumbar epidural anaesthesia using non-stylet multiport catheters via the caudal approach to administer hypertonic 5% lignocaine (HL) or hypertonic 0.5% bupivacaine (HB) to the flank in standing cattle. Materials and methodsSix healthy adult cattle weighing 310-455 kg received 0.2 mg/kg HL or 0.025 mg/kg of HB; control animals received 0.9% saline solution. All drugs were injected into the dorsolumbar epidural space via a caudal approach through a nonstylet multiport catheter. Each animal received each treatment at random. Evaluations of anaesthesia, ataxia, heart rate, arterial pressures, respiratory rate and rectal temperature were obtained at 0 (basal), 5, 10, 15, 30, 45, 60, 75, and 90 min after epidural injection and then at 30-min intervals until loss of anaesthesia. All animals received a standard noxious stimulus and a 4-point scale was used to score the response. A second scale was used to score ataxia. ResultsThe duration of anaesthesia in the upper and lower flanks in cattle was 68 Ϯ 12 and 110 Ϯ 15 min (mean Ϯ SD) after dorsolumbar epidural HL or HB, respectively. Both hypertonic local anaesthetics produced a mild ataxia. The systemic changes were within acceptable limits in these clinically healthy cattle. ConclusionIn standing cattle the dorsolumbar epidural injection of hypertonic lignocaine provided faster onset of anaesthesia and fewer cardiovascular effects, but had a shorter duration of anaesthesia than hypertonic bupivacaine.

Segmental dorsolumbar epidural analgesia with ketamine administered via multiple-port catheters by use of the caudal approach in cattle was feasible, and the cattle remained standing with minimal adverse effects. Further studies are necessary to determine whether this technique provides optimal conditions to allow surgery in standing cattle.

In horses with intermittent dorsal displacement of the soft palate (DDSP), the free border of the soft palate becomes dislodged from its normal subepiglottic position and obstructs the nasopharyngeal lumen, usually during high-intensity exercise. Persistent DDSP is a rare clinical presentation, occurring at rest, in which horses are unable, or only briefly able, to replace the soft palate into the correct anatomical position. This retrospective study examined the hypothesis that horses with persistent and intermittent DDSP would have a different laryngohyoidal position. All horses had been treated with laryngeal tie-forward surgery, and the outcome of this technique was also evaluated. Fifteen horses with persistent DDSP were identified from the medical records of all horses presented over a six-year period to the Cornell University Hospital for Animals. During the same period, 336 horses were diagnosed with intermittent DDSP; 15 horses from this group were matched by age, sex and breed to each of the horses with persistent DDSP. Lateral radiographs of the larynx were taken before and within 24 hours of surgery; radiographic obliquity and head angle were analysed to assess possible effects on laryngohyoidal position. Seven of the horses with persistent DDSP were treated with laryngeal tie-forward alone, but eight horses continued to have persistent DDSP and required subsequent treatment by laser staphylectomy; 13 horses returned to racing. Horses with persistent DDSP were shown to have a more caudal larynx (that is, ossification of the thyroid cartilage), a more caudal and dorsal basihyoid bone, and a more dorsal thyrohyoid-thyroid articulation than horses with intermittent DDSP.