Effects of naloxone in treating hemorrhagic shock in dogs with maintained baroreceptor responsiveness

The efficacy of treating hemorrhagic shock with naloxone in conjunction with fluids, compared with fluid therapy alone, was studied. Previously instrumented dogs were anesthetized with 0.04 mg of fentanyl/kg + 2.2 mg of droperidol/kg and pentobarbital sodium (to effect). Blood was withdrawn from each animal to achieve and maintain a mean arterial blood pressure of 40 to 50 mm of Hg for the first 2 hours of the experiment (t = 0 to 120 minutes). At t = 120 minutes, IV fluid administration was begun (all dogs) and continued for 1 hour (lactated Ringer's solution at a dosage of 70 ml/kg/hr). Hypothermia was corrected. Control dogs were given no other treatment. Dogs in the naloxone plus fluids group were given an IV bolus of naloxone (1 mg/kg) at t = 120 minutes and 1 mg of naloxone/kg/hr in the fluids from t = 120 to t = 180 minutes. Treatment (either naloxone plus fluids or fluids alone) was stopped at t = 180 minutes, and measuring of response was continued for an additional hour (posttherapeutic period). Significant differences were not seen in mean arterial pressures, left ventricular peak systolic pressures, dP/dt max, time constant T (a measure of left ventricular elasticity), and mean pulmonary arterial pressures between the dogs given naloxone and fluid therapy and those given fluid therapy alone. All dogs in both groups survived the procedure.     

ESTIMATION OF SOFT TISSUE INTERPOSITION AFTER FEMORAL HEAD AND NECK EXCISION IN DOGS USING VENTRODORSAL PELVIC RADIOGRAPHY

Extended-hip ventrodorsal pelvic radiographs performed on 16 dogs after femoral head and neck excision, with (n = S) and without (n = 8) biceps femoris interpositional muscle flaps, were used to estimate the relative amount of soft tissue interposition between the femoral ostectomy site and acetabulum. A linear measurement was made of the shortest distance between the femoral ostectomy and the acetabulum. The linear measurement was capable of determining the presence of biceps femoris muscle flaps in most dogs prior to flap atrophy or necrosis, but failed to be predictive of limb function as determined by functional limb usage grading, force plate analysis, and thigh circumference measurements.     

Recurrence rate of presumed thoracolumbar intervertebral disc disease in ambulatory dogs with spinal hyperpathia treated with anti-inflammatory drugs: 78 cases (1997–2000)

Objective: To determine the recurrence rate of clinical signs in dogs with spinal hyperpathia and mild neurological deficits due to presumed Hansen Type 1 thoracolumbar intervertebral disc disease (IVDD) that were managed medically with anti‐inflammatory agents, and to compare the recurrence rates between dogs treated with corticosteroids and those treated with nonsteroidal anti‐inflammatory drugs (NSAIDs). Design: Retrospective study. Setting: Private veterinary emergency clinic in a large metropolitan area. Animals, interventions, and measurements: Medical records were used to ascertain study eligibility, record patient signalment and condition severity, and document medical treatment regimen. Each dog was assigned a severity score: (1) spinal hyperpathia with no neurological deficits, (2) spinal hyperpathia with conscious proprioceptive deficits only, or (3) spinal hyperpathia with ataxia but still retaining ambulatory motor function. Owners of 78 dogs weighing less than 16 kg presented from 1997 through 2000 were sent a questionnaire to determine recurrence rate. Main results: All dogs recovered from the initial episode; 39 experienced recurrence and 39 did not. There was no statistically significant relationship between gender, age, or severity score and recurrence rate. Dogs treated with NSAIDs or methylprednisolone sodium succinate (MPSS) were less likely to experience recurrence than dogs treated with corticosteroids other than MPSS. Conclusion: A 50% recurrence of presumed IVDD occurred in this population of dogs after treatment with NSAIDs or corticosteroids. Those treated with NSAIDs or MPSS were less likely to experience a recurrence.     

Measurement of body temperature by use of auricular thermometers versus rectal thermometers in dogs with otitis externa

OBJECTIVE: To compare measurements of body temperature obtained with auricular thermometers versus rectal thermometers in dogs with otitis externa. DESIGN: Prospective study. ANIMALS: 100 client-owned dogs: 50 with and 50 without clinical evidence of otitis externa. PROCEDURE: Dogs were evaluated for the presence of otitis externa on the basis of clinical signs, otoscopic examination, and cytologic evaluation of ear exudate. Auricular and rectal temperatures were obtained simultaneously in all dogs prior to and following ear examination. RESULTS: There was a high correlation between auricular and rectal temperatures in dogs with otitis externa both prior to and after ear manipulation. Significant differences were not detected in temperature measurements among dogs with different degrees of otitis externa. CONCLUSIONS AND CLINICAL RELEVANCE: Auricular temperature readings obtained by use of an auricular thermometer in dogs with otitis externa are accurate measurements of body temperature, compared with rectal temperature measurements. Temperature measurements are reliable before and after examination of the ear canal.     

When less is more: heterogeneity in grass patch height supports herbivores in counter-intuitive ways

Herbivores are an integral part of the African landscape and have evolved with the vegetation to create the savanna landscape. Managers of these landscapes can benefit from a better understanding of how indigenous herbivores use the landscape to which they are adapted. In this study we observed which patches were frequently utilised, by doing regular monthly road counts, grass height observations and dung counts on selected short grass patches in the Kruger National Park. Smaller-framed impala and blue wildebeest (meso-herbivores) were most regularly seen on these nutritious patches, while from dung deposits it was clear that the even larger-framed buffalo (mega-herbivores) spent time there. This preference can be explained by considering the nutritional needs and food intake of the herbivores. Smaller-framed herbivores seem to be able to satisfy their dietary requirements on the high-quality forage patches, while larger-framed herbivores seem to supplement the quality forage by also spending foraging time on areas of higher grass biomass. From this insight we propose that range management should take herbivore preferences into account and allow herbivores to select and concentrate their foraging on the most nutritious forage. This approach is likely to decrease inputs while allowing animals to maintain or increase production.     

Bone Morphogenetic Protein‐6 (BMP‐6) Stimulates the Antrum Formation by the Regulation of its Signalling Pathway in Caprine Pre‐antral Follicles Cultured In Vitro

BMP‐6 has been found to be important to ovarian cells and oocyte, as well as to uterus. Thus, this study investigated the effect of bone morphogenetic protein (BMP‐6) and recombinant follicle‐stimulating hormone (rFSH) alone or in combination on the in vitro culture (IVC) of isolated caprine secondary follicles (Experiment 1) and the mRNA levels for BMP receptors/Smad signalling pathway (BMPR1A, BMPR2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7 and SMAD8) in vivo and in vitro using BMP‐6 (Experiment 2). Secondary follicles were cultured in αMEM⁺ alone (control medium) or supplemented with BMP‐6 at 1 or 10 ng/ml and rFSH alone or the combination of both BMP‐6 concentrations and rFSH. The results from Experiment 1 showed that the antrum formation rate was higher in the BMP‐6 at 1 ng/ml (p < 0.05) than in MEM. In Experiment 2, the mRNA expression for BMPR2, SMAD1, SMAD5 and SMAD6 was detected in non‐cultured control and after in vitro culture (MEM and 1 ng/ml BMP‐6); while the expression of SMAD7 and SMAD8 mRNA was only detected after IVC, SMAD4 was only detected in the BMP‐6 at 1 ng/ml treatment. In conclusion, the low BMP‐6 concentration positively influenced antrum formation and ensured normal mRNA expression for BMP receptor and Smads after IVC of caprine secondary follicles.     

Evaluation of the specificity of three enzyme-linked immunosorbent assays for detection of antibodies against Salmonella in bovine bulk milk

Background

The Swedish Salmonella control program has been running for decades and has resulted in a low prevalence of Salmonella in Swedish food producing animals. Routine bacteriology is used to detect Salmonella, however, bacteriology is time consuming, costly and has a low sensitivity. Different enzyme-linked immunosorbent assays (ELISAs) have been developed for detection of antibodies against Salmonella Dublin and S. Typhimurium in bovine bulk milk, individual milk samples as well as in sera. Screening bulk milk for antibodies against Salmonella spp. could improve the cost-effectiveness of the surveillance in Swedish dairy cattle, but as characteristics of tests may vary in different populations, tests should always be evaluated in the specific population where they will be used. Hence, the aim of this study was to evaluate the specificities of three bovine ELISAs when used to analyse bulk milk samples from Swedish dairy cattle. A second aim was to compare the performance of the two Dublin ELISAs tested.

Methods

Bulk milk samples for analysis were randomly selected from samples collected within the Swedish bulk milk sampling scheme and analyzed with the three ELISAs; a Danish in-house Dublin ELISA, PrioCHECK® Salmonella Ab bovine Dublin ELISA and PrioCHECK® Salmonella Ab bovine ELISA (hereafter named mixed ELISA). The specificities of the ELISAs were calculated assuming a disease-free status in Sweden i.e. that all test positive samples were assumed to be false positive results. This assumption can be used when a disease is known to be infrequent.

Results

The calculated specificities of the two Dublin ELISAs and the mixed ELISA, when using the producer’s recommended cut-off value of the corrected optic-density percent (ODC%) were 99.4% (95% Confidence Interval (CI): 98.8% -99.8%), 99.4% (95% CI: 98.8% -99.8%) and 97.9% (95% CI: 96.8% -98.7%), respectively. The correlation between the ODC% values of the two Dublin ELISAs was 0.83.

Conclusions

We conclude that the evaluated ELISAs have sufficiently high specificities to be used as supplement to bacteriological examinations in the Swedish Salmonella control program in cattle as well as a primary screening test in routine surveillance for S. Dublin.     

A comparison of auricular, rectal and pulmonary artery thermometry in dogs with anesthesia-induced hypothermia

Objective: To determine if a correlation exists among auricular, rectal and pulmonary artery (PA) temperatures in hypothermic dogs. Design: Prospective study. Setting: Angiography suite at a college of veterinary medicine. Animals: Sexually intact female research hounds (13.9–25.4 kg; n=8). Measurements and main results: Dogs were anesthetized for instrumentation with a percutaneously placed, thermistor‐tipped, PA catheter. Anesthesia was maintained until the core body temperature decreased to 36.6°C (97.8°F). Anesthesia was discontinued, and auricular and rectal temperatures were obtained every 15 minutes until the PA temperature reached 38.3°C (100.9°F). A strong correlation was noted among the 3 methods of temperature measurement (P<0.001; R≥0.846). No statistical difference was detected among measurement methods at baseline, the minimum temperature attained, nor the median temperature attained. However, at the maximum temperature attained, auricular measurements (37.7±0.4°C or 99.8±0.7°F) were lower than either the rectal (38.3±0.3°C or 100.9±0.5°F) or PA (38.3±0.3°C or 100.9±0.5°F) temperature measurements (P=0.001). Conclusion: There is a strong correlation among rectal, auricular and PA temperatures. Auricular temperature may be used to monitor core body temperature during postoperative rewarming; however, it might be slightly lower than core temperature as normothermia is reached.     

Epigallocatechin‐3‐gallate (EGCG) and green tea polyphenols do not improve stallion semen parameters during cooling at 4°C

Stallion semen storage for artificial insemination is mainly based on liquid cooled storage. In many stallions this technique maintains sperm quality for an extended period of time (24–72 hr) at 7°C. While this technique is commonly used in the horse industry, there can be a decline in fertility in some stallions, due to an inability of their sperm to tolerate the cool storage process. The aim of the present work was to evaluate the effect of two natural antioxidants (epigallocatechin‐3‐gallate (EGCG) at 20, 60 and 120 μm and green tea polyphenols, and p at .001, .01 and .1 mg/ml) on some sperm parameters (sperm motility, viability/acrosome integrity and DNA quality) in extended semen immediately after its collection (T0) and after 2, 6, 24 and 48 hr of cool storage. Two ejaculates from three trotter stallions were analysed after 48 hr of storage at 4°C. No beneficial effect on the analysed parameters was observed: the two antioxidants were not able to improve sperm quality after 48 hr of storage. These results are in agreement with previous findings on the effect of different antioxidants reported by other researches, who have demonstrated that stallion semen keeps good antioxidant capacity after dilution for 24 hr. In conclusion, the positive effect exerted by antioxidant molecules in other species is not confirmed in the equine one.     

Impact of Ultra‐Rapid Freezing on the Motility,Morphology, Viability and Acrosome Integrity of Epididymal Cat Sperm Diluted in Sucrose‐Based Extenders

The objective of the present study was to investigate the influence of different sucrose‐based extenders on the motility, morphology, viability and acrosomal integrity of epididymal cat spermatozoa cryopreserved by ultra‐rapid freezing method. Nine cats were castrated, and collected semen was diluted 1 : 1 with Dulbecco`s phosphate‐buffered saline‐BSA1%‐based extender supplemented with different sucrose concentrations (0, 0.25, 0.4 and 0.6 m ). After ultra‐rapid freezing, samples were thawed and sperm motility, morphology, viability and acrosome status were assessed. At thawing, the number of progressively motile (p < 0.01) and morphologically normal (p < 0.01) sperm was higher in the sucrose‐supplemented groups than in the sucrose‐free group. Viability of spermatozoa cryopreserved without sucrose was significantly reduced. In extender supplemented with 0.4 m sucrose, spermatozoa viability showed higher values (57.0 ± 4.7; p < 0.01). No significant differences were detected among groups for sperm acrosome integrity. Results support that cat sperm survive after ultra‐rapid freezing using sucrose as a cryoprotectant, and the best results were achieved when 0.4 m of sucrose was used. This is the first report on sperm ultra‐rapid freezing of cat sperm and further studies on extenders, sperm management or cryovials should be carried out to improve sperm cryosurvival.