MAGNETIC RESONANCE ARTHROGRAPHY OF THE CANINE STIFLE JOINT TECHNIQUE AND APPLICATIONS IN ELEVEN MILITARY DOGS

The stifle joints of eleven military working dogs were evaluated using conventional magnetic resonance (MR) imaging and MR arthrography. A protocol optimizing MR imaging of the canine stifle joint is discussed, as well as potential uses for administration of intra-articular gadolinium. The technique for performing MR arthrography is described, and post-contrast image findings are reviewed. MR arthrography was performed by using an intra-articular injection of diluted gadolinium. Consistently good quality images were obtained, and no complications were clinically detected following MR arthrography. Cranial cruciate ligament abnormalities were seen in six dogs, meniscal abnormalities were visualized in nine menisci, and synovitis and medial ligament strain were seen in eight dogs. Surgical and post-mortem confirmation of these findings is discussed in seven dogs. Although MR arthrography adds an invasive procedure to conventional MR imaging, it can provide useful information on pathologic changes in the canine stifle joint.     

Use of bethanechol and metoclopramide in horses with duodenitis/proximal jejunitis: 13 cases (1987–1993)

All horses diagnosed with duodenitis/proximal jejunitis (DPJ) at the Texas Veterinary Medican Center between January 1, 1987 and July 1, 1993 were included in a retrospective study to evaluate the therapeutic and prognostic value of bethanechol and metoclopramide as gastrointestinal prokinetic drugs in horses with DPJ treated at our clinic, and to compare the clinical outcome of horses with DPJ treated with these drugs and those with DPJ that were not treated. During the study period, 70 horses diagnosed with DPJ were admitted to the clinic. Of these 70 horses, 18(25.7%) were treated with bethanechol, metoclopramide, or both; 13 of the 18 treated horses received more than one dose of either drug. No adverse effects of treatment with these drugs were noted. A precise therapeutic plan and clinical benefit of bethanechol, metoclopramide, or both coul not be determined from this retrospective study. The use of these gastrointestinal prokinetic drugs in horses with DPJ appeared to have prognostic value. Horses that did not respond to treatment with these gastrointestinal prokinetic drugs within 24 hours were not discharged alive.     

Detomidine-Propofol Anesthesia for Abdominal Surgery in Horses

OBJECTIVE: To evaluate propofol for induction and maintenance of anesthesia, after detomidine premedication, in horses undergoing abdominal surgery for creation of an experimental intestinal adhesion model. STUDY DESIGN: Prospective study. ANIMALS: Twelve horses (424 +/- 81 kg) from 1 to 20 years of age (5 females, 7 males). METHODS: Horses were premedicated with detomidine (0.015 mg/kg i.v.) 20 to 25 minutes before induction, and a propofol bolus (2 mg/kg i.v.) was administered for induction. Propofol infusion (0.2 mg/kg/min i.v.) was used to maintain anesthesia. The infusion rate was adjusted to maintain an acceptable anesthetic plane as determined by muscle relaxation, occular signs, response to surgery, and cardiopulmonary responses. Oxygen (15 L/min) was insufflated through an endotracheal tube as necessary to maintain the SpO2 greater than 90%. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressures, heart rate (HR), electrocardiogram (ECG), respiratory rate (RR), SpO2 (via pulse oximetry), and nasal temperature were recorded at 15 minute intervals, before premedication and after induction of anesthesia. Arterial blood gas samples were collected at the same times. Objective data are reported as mean (+/-SD); subjective data are reported as medians (range). RESULTS: Propofol (2.0 mg/kg i.v.) induced anesthesia (mean bolus time, 85 sec) within 24 sec (+/-22 sec) after the bolus was completed. Induction was good in 10 horses; 2 horses showed signs of excitement and these two inductions were not smooth. Propofol infusion (0.18 mg/kg/min +/- 0.04) was used to maintain anesthesia for 61 +/- 19 minutes with the horses in dorsal recumbency. Mean SAP, DAP, and MAP increased significantly over time from 131 to 148, 89 to 101, and 105 to 121 mm Hg, respectively. Mean HR varied over time from 43 to 45 beats/min, whereas mean RR increased significantly over anesthesia time from 4 to 6 breaths/min. Mean arterial pH decreased from a baseline of 7.41 +/- 0.07 to 7.30 +/- 0.05 at 15 minutes of anesthesia, then increased towards baseline values. Mean PaCO2 values increased during anesthesia, ranging from 47 to 61 mm Hg whereas PaO2 values decreased from baseline (97 +/- 20 mm Hg), ranging from 42 to 57 mm Hg. Muscle relaxation was good and no horses moved during surgery: Recovery was good in 9 horses and acceptable in 3; mean recovery time was 67 +/- 29 minutes with 2.4 +/- 2.4 attempts necessary for the horses to stand. CONCLUSIONS: Detomidine-propofol anesthesia in horses in dorsal recumbency was associated with little cardiovascular depression, but hypoxemia and respiratory depression occurred and some excitement was seen on induction. CLINICAL RELEVANCE: Detomidine-propofol anesthesia is not recommended for surgical procedures in horses if dorsal recumbency is necessary and supplemental oxygen is not available (eg, field anesthesia).