A METHOD OF MOUNTING A GAMMA DETECTOR AND YOKE ASSEMBLY FOR EQUINE NUCLEAR IMAGING

A scintillation detector assembly capable of providing the range of movement and flexibility needed for the investigation and diagnosis of equine-related health problems was required for the nuclear medicine facility of the Equine Research Centre, Guelph, Ontario. The planning, technique and modifications used to mount the gamma detector and yoke assembly are detailed herein. The system has been successfully used for the nuclear scans in horses, and demonstrates the practicality, safety and usefulness of equipment adaptation for large animal imaging.     

The cardiorespiratory and anesthetic effects of clinical and supraclinical doses of alfaxalone in cats

ObjectiveTo determine the cardiorespiratory and anesthetic effects of 0, 5, 15, and 50 mg kg^?1 intravenous (IV) alfaxalone in hydroxypropyl beta cyclodextrin (Alfaxan; Jurox Pty Ltd, Rutherford, NSW, Australia) in cats.Study designFour treatments of alfaxalone were administered in sequential order.AnimalsEight healthy adult cats (four male; four female) weighing between 3.71 and 5.91 kg.MethodsCats were instrumented for hemodynamic measurements. Four (0, 5, 15, and 50 mg kg^?1) IV doses of alfaxalone were administered over one minute, with a 3-hour washout period between doses 0, 5, and 15 mg kg^?1 on Day 0. The 50 mg kg^?1 treatment was administered 24 hours later. Measurements of heart rate, aortic systolic, mean, and diastolic blood pressures, pulmonary arterial and right atrial mean pressures, cardiac output, respiratory rate, tidal and minute volumes, and arterial blood pH and blood gases (PaO₂, PaCO₂) were performed at pre-determined intervals. Systemic vascular resistance and rate pressure product were calculated. The quality of induction, maintenance, and recovery from anesthesia and the response to noxious stimulation were categorically scored.ResultsAlfaxalone administration resulted in dose-dependent cardiorespiratory depression. Decreases in arterial blood pressure and increases in heart rate occurred at higher doses. Most variables returned to baseline by 15-30 minutes. Respiratory rate, minute volume, and PaO₂ decreased. Apnea was the most common side effect. Induction and maintenance quality were judged to be good to excellent at all doses and quality of recovery good to excellent at all but the 50 mg kg^?1 dose. The duration of anesthesia and unresponsiveness to noxious stimulation increased with dose. The administration of the 50 mg kg^?1 dose produced marked cardiorespiratory depression and apnea.Conclusions and clinical relevanceAlfaxalone produced dose-dependent anesthesia, cardiorespiratory depression and unresponsiveness to noxious stimulation in unpremedicated cats. Hypoventilation and apnea were the most common side effects.     

RADIOLOGIC DETECTION OF OVINE HYDATIDOSIS

Unilocular hydatid disease in humans is of world-wide importance. While surgical removal is the usual treatment, the drug mebendazole has been reported as being active against the cyst wall; other potentially valuable drugs are likely to become available. Naturally infected sheep would be a suitable model for testing drugs against hydatid disease, and a method for selecting infected animals from flocks in areas with a high incidence of this condition would be valuable. To determine whether radiographic examinaiton of the thorax would be a satisfactory method of identifying cysts, the authors radiographed and then killed 93 cull ewes. At necropsy, the lungs were examined, and the nature and distribution of cysts were noted and compared with the findings obtained separately by radiology. A similar study was made on a sheep infected experimentally with a large number of Echinococcus granulosus ova. The technique of thoracic radiography in sheep is described. These studies indicate that there are four different morphologic manifestations of ovine hydatid cyst that may be reliably identified by radiologic examination. They also show that thoracic radiology provides a method for detecting active hydatid infection in sheep and for following the progress of individual cysts.     

Ventral Rhinotomy in the Dog and Cat

The nasal cavities of 14 dogs and three cats were explored surgically using a ventral rhinotomy. The exposure achieved through this approach was considered to be equal to a dorsal rhinotomy. One animal died during the immediate postoperative period from perforation of a gastric ulcer. The other animals recovered well and had no significant complications. The long-term survival of the animals was consistent with previous reports for their diseases. Ventral rhinotomy is no more difficult than dorsal rhinotomy, has less patient morbidity and fewer postoperative complications, and is more cosmetically acceptable.     

Biomechanical Comparison of Six Suture Configurations Using a Large Diameter Polyester Prosthesis in the Muscular Process of the Equine Arytenoid Cartilage

Objective— To compare biomechanical properties of 6 suture configurations using a large diameter polyester prosthesis in the muscular process (MP) of the arytenoid cartilage and to determine failure mode.
Study Design— Experimental study.
Sample Population— Cadaveric equine larynges (n=121).
Methods— Suture configurations (4 single, 2 double) were inserted, and then constructs were tested in a single-cycle to failure at a 100 mm/min distraction. Load deformation curves were generated to assess the biomechanical properties of each construct. A 1-way ANOVA was used to compare the mean differences in construct failure force, cricoarytenoid joint (CAJ) disarticulation force, and energy stored at failure. A 2-sample t-test was used to compare single versus double suture patterns and a Fisher's exact test was used to compare failure mode.
Results— Both construct and CAJ failure force were significantly greater ( P <.05) for double suture patterns compared with single suture patterns; however, there were no significant differences in energy stored at construct failure. Failure at the MP accounted for ≥50% of construct failures for 3 of the single suture patterns and 1 of the double suture patterns tested. The remaining 2 patterns had an increased frequency of clamp failures as well as failure of the cricoid cartilage.
Conclusions— Sutures that sufficiently engage the spine of the MP alone or in conjunction with a second suture were found to be biomechanically superior.
Clinical Relevance— Engaging the spine of the MP appears to result in the most biomechanically sound laryngeal construct.     

Disseminated Intravascular Coagulation in Dogs: Review of the Literature

Diagnosis of Disseminated Intravascular coagulation (DIC) is controversial in both human and veterinary medicine. This article reviews the available literature in human and veterinary medicine regarding the etiology, pathophysiology, and diagnosis of DIC with emphasis on the diagnosis of DIC in dogs. Controversy surrounding the diagnosis of DIC arises from the complex nature of the disease itself, in addition to the absence of a consensus strategy for laboratory testing. The available literature indicates that dogs diagnosed with DIC possessed various hemostatic function testing abnormalities, typically possessed an underlying disease that predisposed to DIC, but may or may not have had clinically identifiable hemorrhage or thrombosis. Additionally, the hemostatic function testing utilized in diagnosis is not uniform. Generalizations about the usefulness of individual assays or diagnostic strategies cannot be formulated because of the marked diversity of the types of cases studied, as well as the small number of cases reported in the literature. (Vet Emerg & Crit Care, 1998; 8: 29–45)