Prolongation of xylazine/ketamine induced recumbency time with temazepam in horses

Short term anaesthesia induced with xylazine and ketamine was compared to a combination of xylazine, ketamine and temazepam (a benzodiazepine) in six adult horses. Duration of recumbency was significantly prolonged when temazepam was administered with xylazine and ketamine. No significant differences in heart rate, respiratory rate, blood pressure or arterial pH, pCO2 and pO2 were seen between the xylazine and ketamine combination plus temazepam, and xylazine and ketamine combination only treated horses.     

Halothane-sparing effect of benzodiazepines in ponies

The halothane-sparing effect of 2 benzodiazepines, diazepam and temazepam, were investigated in ponies by measuring the minimum alveolar concentration (MAC) for halothane before and after drug administration. The MAC value for halothane decreased 29% and 16% when either 0.044 mg/kg of diazepam or 0.044 mg/kg of temazepam, respectively, was administered intravenously. Heart rate, respiratory rate, systolic and mean arterial blood pressure, and expired CO2 were also measured. No differences were present in these variables before and after drug administration nor were differences noted between the benzodiazepines.     

Comparison of topical lidocaine/prilocaine anesthetic cream and local infiltration of 2% lidocaine for episioplasty in mares

Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty-two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8-12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was conducted using standard methods, but employing simple interrupted sutures. Horses were not sedated and use of a twitch was recorded. Four millimeter punch biopsies were harvested 1, 3, and 10 days following episioplasty and scored for degree of inflammation by a blinded pathologist. Clinical inflammation scores were assigned when biopsies were obtained. Seven of 11 horses receiving lidocaine infiltration required twitching, but none of the horses that received the anesthetic cream required twitching. Six of 11 and seven of 11 of the lidocaine and anesthetic cream groups, respectively, required twitching for episioplasty. Except for the clinical scores on day 3, no statistical differences for clinical and histopathologic scores between samples from the two treatment groups for a given day were identified. Use of lidocaine/prilocaine topical anesthetic cream was as effective as lidocaine infiltration in providing local anesthesia when performing episioplasty in mares. Its use decreased the need for twitching horses as well as the risk of deformation of the labia caused by lidocaine infiltration.     

Quantification,Morphology and Ultrastructure of Preantral Follicles of Buffalo (Bubalus bubalis) Foetuses

The objective of this study was to determine the number, morphology and ultrastructure of preantral ovarian follicles of buffalo (Bubalus bubalis) foetuses at different ages. Quantification revealed number of primordial, primary and secondary follicles of 48 857 ± 17 506, 26 000 ± 20 452, 18 428 ± 10 875 and 18 375 ± 19 690, 225 ± 349, 326 ± 288 at 12–34 cm and 35–60 cm crown rump length (CRL), respectively. Follicular diameter values were 28.9 (±3.4), 34.7 (±5.9) and 59.4 (±12.6) μm; oocyte diameters were 21.7 (±2.8), 24.3 (±3.4) and 33.0 (±7.7) μm, and the numbers of follicular cells in the follicle equatorial section were 7.1 (±1.4), 12.0 (±2.4) and 13.8 (±2.4) for primordial, primary and secondary follicles, respectively. The primordial follicle consisted of an oocyte surrounded by a layer of flattened follicular cells with a normally eccentric oocyte nucleus. Dispersed Golgi complex, smooth endoplasmic reticulum, rounded mitochondria and several lipid vesicles were observed in the cytoplasm and cell junctions between the follicle cell membranes and the oocyte. This work describes the number, morphometry and ultrastructure of preantral follicles of buffalo foetuses, concluding that folliculogenesis is established between 8 and 34 cm CRL and that follicle number varies individually and according to age and that further studies are needed in this species.     

Clinical use of positive-pressure ventilation in the horse

Positive-pressure ventilation is used to provide improved ventilatory support during anesthesia in the horse. Because of the horse's size and the physiologic changes it undergoes during anesthesia, however, the use of positive-pressure ventilation does not always provide the improvement seen in smaller species. Careful attention to respiratory rate, inspiratory pressure, and I:E ratio minimizes the negative aspect of IPPV on the cardiovascular system. The goal of future ventilatory techniques will be to improve oxygenation without cardiovascular compromise and to do so at a reasonable cost to the client.     

Effects of allopurinol in experimental endotoxin shock in horses

The effect of allopurinol pretreatment 12 hours before an intraperitoneal challenge with a sublethal dose of Escherichia coli endotoxin (50 micrograms kg-1) was evaluated in 18 horses. The horses were divided among three equal groups: 1-endotoxin alone; 2-5 mg allopurinol kg-1 bodyweight plus endotoxin; and 3-50 mg allopurinol kg-1 bodyweight plus endotoxin. A variety of evaluation parameters were used. No differences among the groups were noted in rectal temperature, heart rate, respiration rate, haematological values, blood PaO2, blood PaCO2, blood pH or blood bicarbonate. Significant (P less than 0.05) differences between the groups were noted as regards the changes in capillary refill time, base excess, blood glucose, blood lactate, blood beta-glucuronidase and recumbency time. The protection afforded by 5 mg allopurinol kg-1 appeared to be superior to that with 50 mg allopurinol kg-1.     

Detection of Follicular Apoptosis in Water Buffalo (Bubalus bubalis) Ovary by Histology and Nick End Labelling Technique

The objective of this experiment was to assess the features and extent of follicular apoptosis in the water buffalo (Bubalus bubalis) ovary using classical histology and nick end labelling technique. Ovaries (n = 40) procured from the slaughterhouse were used for the study. The sections (5 μm) were used for detection of terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick end labelling (TUNEL) and classical histology (H&E). Those follicles showing ≥ 5% TUNEL positivity (TUNEL assay) and pyknotic nuclei (histology) in granulosa cells were classified as atretic. Based on histology, the atretic primary and secondary follicles (%) were 93.82 and 95.62 respectively. The histology study reveals that the rates (%) of atresia in <1, 1–3, 3–5 mm and >5 mm were 36.90, 40.50, 62.84 and 74.5 respectively. Further the atretic tertiary follicles (%) were significantly lower than the primary and secondary classes of follicles. TUNEL assay reveals that the atretic rate (%) of tertiary follicles in <1, 1–3, 3–5 and ≥ 5 mm class follicles were 50.88, 53.84, 81.81 and 36.36 respectively. The percentage of atresia in >5 mm diameter follicles were significantly lower in TUNEL than histology. Percentages of granulosa and thecal cells positive for atresia by TUNEL were 30.7 ± 0.53 and 13.82 ± 0.18 respectively per follicle. The initial structural changes in atretic follicles were seen primarily in the granulosa cells. In severely atretic follicles TUNEL positive granulosa cells along with theca cells have to be considered in assessing the rate and extent of atresia.