MAGNETIC RESONANCE IMAGING FINDINGS OF EQUINE SOLAR PENETRATION WOUNDS

The magnetic resonance (MR) imaging features, signalment, clinical history and outcome of 55 horses with a penetrating sole injury were evaluated. Our aim was to describe MR imaging findings within the hoof capsule, assess the utility of the technique and give recommendations for the optimal MR imaging protocol to evaluate such injuries. Data from five equine hospitals were analyzed retrospectively. The tract was more likely to be visualized in animals scanned within the first week postinjury. There was no significant predisposition based on breed, age, or gender. T2*W transverse sequences were the most useful for assessment of solar penetrations due to their orientation perpendicular to the deep digital flexor tendon, the reduced scanning time, and the T2* capability of enhancing magnetic susceptibility caused by hemorrhage.     

Retrospective analysis of detomidine infusion for standing chemical restraint in 51 horses

Objective To assess the effectiveness of a detomidine infusion technique to provide standing chemical restraint in the horse. Design Retrospective study. Animals Fifty‐one adult horses aged 9.5 ± 6.9 years (range 1–23 years) and weighing 575 ± 290.3 kg. Methods Records of horses presented to our clinic over a 3‐year period in which a detomidine infusion was used to provide standing chemical restraint were reviewed. Information relating to the types of procedure performed, duration of infusion, drug dosages and adjunct drugs administered was retrieved. Results Detomidine was administered as an initial bolus loading dose (mean ± SD) of 7.5 ± 1.87 µg kg^?1. The initial infusion rate was 0.6 µg kg^?1 minute^?1, and this was halved every 15 minutes. The duration of the infusion ranged from 20 to 135 minutes. Twenty horses received additional detomidine or butorphanol during the procedure. All horses undergoing surgery received local anesthesia or epidural analgesia in addition to the detomidine infusion. A wide variety of procedures were performed in these horses. Conclusions Detomidine administered by infusion provides prolonged periods of chemical restraint in standing horses. Supplemental sedatives or analgesics may be needed in horses undergoing surgery. Clinical relevance An effective method that provides prolonged periods of chemical restraint in standing horses is described. The infusion alone did not provide sufficient analgesia for surgery and a significant proportion of animals required supplemental sedatives and analgesics.     

Effect of Preoperative Erythromycin or Dexamethasone/Vitamin C on Postoperative Abomasal Emptying Rate in Dairy Cows Undergoing Surgical Correction of Abomasal Volvulus

Objective— To determine the effects of preoperative erythromycin or combined dexamethasone/vitamin C treatment on postoperative abomasal emptying rate in cows undergoing surgical correction of abomasal volvulus (AV).
Study Design— Prospective, controlled, clinical study using a convenience sample.
Animals— Lactating Holstein–Friesian cows (n=45) with AV were alternately assigned to 3 groups (n=15): group C: untreated (control); group E: erythromycin (10 mg/kg intramuscularly [IM]); group D: dexamethasone (0.02 mg/kg intravenously [IV]) and vitamin C (10 mg/kg IV).
Methods— Drugs were administered 1 hour before surgical correction of AV. d -xylose solution (50%, 0.5 g/kg body weight) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum d -xylose concentration were periodically obtained. Time to maximal serum d -xylose concentration (T_max-model) was pharmacokinetically determined.
Results— Abomasal emptying rate was significantly ( P <0.05) faster in group E (T_max-model=182±69 min; mean±SD) than in group C cows (T_max-model=237±64 min). Abomasal emptying rate was similar in group D (T_max-model=196±47 min) and group C. Both treatments improved postoperative milk yield within 1 day after surgery.
Conclusion— Preoperative injection of erythromycin (10 mg/kg IM) is an effective method for ameliorating postoperative abomasal hypomotility in cows with AV.
Clinical Relevance— Parenteral erythromycin can be recommended for preoperative treatment of cows with AV.     

DEVELOPMENT OF REFERENCE INTERVALS FOR THE LARGE INTESTINAL TRANSIT OF RADIOPAQUE MARKERS IN DOGS

Ten healthy dogs were fed 30 1.5 mm and 10 5 mm radiopaque markers (BIPS, MedID, Grand Rapids) mixed with sufficient quantities of a high fibre diet to meet 25% of their estimated daily caloric requirements. Abdominal radiographs were made at two hour intervals until 90% of the small and large markers had left the colon. The mean residence times (MRT) of each size of marker in the proximal, distal and total colon were calculated using kinetic analysis. The MRT's of the small markers were 4.9 hours (SD 4.4), 7.1 hours (SD 3.3) and 12.0 hours (SD 7.1) respectively. The MRT's of the large markers were not significantly different from the small markers except in the proximal colon where they were significantly shorter (3.2 hours, SD 2.3). Reference colonic filling and colonic transit curves for both sizes of markers were constructed. These may be useful to detect abnormal colonic transit in dogs.     

COMPARISON OF ULTRASONOGRAPHIC AND RADIOGRAPHIC MEASUREMENTS OF CANINE PROSTATE DIMENSIONS

The purposes of this study were to: 1) compare prostatic dimensions measured on radiographic and ultrasonographic images and 2) compare a subjective radiographic assessment of prostate size with a previously-described objective method. Thirty-four male dogs undergoing investigation of prostatic disorders were used. Prostate length and depth were measured from ultrasonographic and radiographic images. A subjective assessment of prostate size ('small', 'normal', or 'enlarged') was made in 29 animals by one of the authors who was unaware of radiographic or ultrasonographic measurements. In addition, the distance from sacral promontory to the pubic brim was also measured. A prostate length or depth of >70% of this distance was defined as 'enlarged' and <70% as 'normal'. After the effects of magnification on radiographic measurements were eliminated, there were no significant differences between prostatic length measured by the two methods. However, a significant difference was obtained between prostatic depth measurements. The subjective assessment agreed with a previously described objective assessment of prostatic size in 21/29 dogs for prostate length but in only 12/29 for depth. Prostatic length varied from 46.6 to 116.4% (mean 75.7%) of the distance from the pubic brim to the sacral promontory. Prostatic depth varied from 33.0% to 94.6% (mean 59.7%) of the same distance. It is recommended that prostate length, rather than depth, be used when evaluating prostate size from lateral abdominal radiographs.