Evidence of the development of ‘domain‐restricted’ expertise in the recognition of asymmetric motion characteristics of hindlimb lameness in the horse

Reasons for performing study: Visual assessment of horses' movements is subjective, affected by bias and dependent on the level of experience of the assessor. However, to date there are no data available on the ability of the human visual system to recognise (a)symmetry in moving objects. Objectives: To investigate, using visual lameness assessment, the limits of human perception and the ability of experienced and nonexperienced individuals to detect asymmetry in 2 moving objects simulating hindlimb lameness in the horse. Methods: Twelve experienced individuals (equine and small animal clinicians), and 24 nonexperienced individuals (undergraduate veterinary students) were presented with computer simulations showing 2 ‘tuber coxae markers’ created using data from both lame and nonperceptibly lame horses, as well as artificial data based on a sine wave. Individuals were asked to classify as symmetrical or asymmetrical, and then rank based on the grade of perceived asymmetry. Repeatability and learning effect were evaluated by repeating the tests on a subset of subjects. Results: The threshold for detection of movement asymmetry was found to be approximately 25% difference in amplitude between the 2 moving objects for all individuals. There was no significant difference between experienced and nonexperienced individuals in the ability to detect asymmetry in the simulations based on artificial data. However, the percentage of correct answers was higher for experienced compared to nonexperienced individuals for simulations based on data from real lame horses. Conclusions: There was a significant difference between experienced and nonexperienced individuals in the ability to identify asymmetric movement based on the pattern seen in a lame horse, as opposed to an artificial pattern for which all individuals showed similar performance. Potential relevance: The study provides the basis for the development of computer simulations that could aid in training veterinarians in the diagnosis of lameness and, even, the objective assessment of expertise in this field.     

Electrocardiographic changes in the growing Mastín Español

Serial electrocardiograms were recorded from 70 Mastín Español dogs in right lateral recumbency, aged between one day and three years, in order to observe the changes in the waveform and intervals, QRS morphology, cardiac rhythm and heart rate caused by their growth. Age and bodyweight caused a gradual increase in the duration and amplitude of the P wave, duration of the PR, QT and RR intervals, amplitude of the R wave and duration of the QRS complex and ST segment. Q wave was observed in nearly all the recordings with different amplitudes. The S wave was only significant in one-day-old animals and QRS morphology showed significant important changes from qrS and rS to qR and qRs morphologies during the first two weeks of life. The T wave increased its amplitude until the age of two months and changed its polarity (from negative to positive) from five months of age onwards. The heart rate decreased until the age of seven months, reaching stabilised values of 110 ± 7-3 beats per minute. Sinus tachycardia was commonplace in animals under one month old and respiratory sinus arrhythmia was found from six months of age. Sex only influenced the duration and amplitude of the T wave. Males had higher mean values than females.     

The relationships between the myocardial bridge and ramus interventricularis paraconalis characteristics in lamb and sheep

The myocardial bridge (MB) is an anomaly that the myocardial fibres cover on a segment of the subepicardial coronary arteries or their branches in domestic animals and humans. The aim of the present study was to determine the relationships between the characteristics of the MB and ramus interventricularis paraconalis at three levels in lambs and adult sheep. Thirty-three hearts (16 lambs and 17 sheep) were used to determine the MB (length, angle and thickness) and vessel (vessel diameter and thicknesses of tunica intima et media of ramus interventricularis paraconalis) characteristics. Independent-samples t test was applied to compare variables between lambs and sheep. Spearman's correlation analysis was conducted to evaluate the relationships between bridge and vessel characteristics at three bridge levels. Length, angle and thickness of myocardial bridges were not significantly different between the lambs and sheep (p > .05). The mean length, angle and thickness were 24.9 ± 16.1 mm, 113.7 ± 11.2° and 1,098 ± 555 µm in 33 hearts, respectively. In lambs, the mean vessel diameters were 1,930 ± 742 µm (1,534–2,325 µm), 1,247 ± 665 µm (893–1,601 µm) and 865 ± 172 µm (774–957 µm) at the pre-bridge, bridge and post-bridge levels, respectively. In sheep, the mean vessel diameters in the same order were 1,861 ± 1,068 µm, 1,337 ± 308 µm and 1,287 ± 549 µm. The bridge prevalence was 100% in the samples examined. In conclusion, coronary arterial diseases related to myocardial bridge should not be expected in sheep for veterinary cardiology practice. It may also be concluded that the cross-breeds of the Awassi and Chios sheep may be useful in experimental studies related to myocardial bridge surgery.     

Comparison of the cardio‐respiratory effects of methadone and morphine in conscious dogs††

The effects of methadone and morphine were compared in conscious dogs. Six animals received morphine sulfate (1 mg/kg) or methadone hydrochloride (0.5 mg/kg [MET0.5] or 1.0 mg/kg [MET1.0]) intravenously (i.v.) in a randomized complete block design. Cardiopulmonary variables were recorded before (baseline), and for 120 min after drug administration. One outlier was not included in the statistical analysis for hemodynamic data. Morphine decreased heart rate (HR) compared to baseline from 30 to 120 min (?15% to ?26%), while cardiac index (CI) was reduced only at 120 min (?19%). Greater and more prolonged reductions in HR (?32% to ?46%) and in CI (?24% to ?52%) were observed after MET1.0, while intermediate reductions were recorded after MET0.5 (?19 to ?28% for HR and ?17% to ?27% for CI). The systemic vascular resistance index (SVRI) was increased after methadone; MET1.0 produced higher SVRI values than MET0.5 (maximum increases: 57% and 165% for MET0.5 and MET1.0, respectively). Compared to morphine, oxygen partial pressure (PaO₂) was lower (?12% to ?13%) at 5 min of methadone (0.5 and 1.0 mg/kg), while carbon dioxide partial pressure (PaCO₂) did not change significantly. It was concluded that methadone induces cardiovascular changes that are dose‐related and is a more potent cardiovascular depressant agent than morphine in conscious dogs.     

Roles of the zona pellucida and functional exposure of the sperm‐egg fusion factor ‘IZUMO’ during in vitro fertilization in pigs

The zona pellucida (ZP) is considered to play important roles in the prevention of polyspermy in mammalian oocytes. However, in pigs we have shown that the presence of the ZP accelerates sperm penetration into the ooplasm during in vitro fertilization (IVF). In the present study, we investigated the effects of the ZP on sperm binding, acrosomal status, and functional exposure of IZUMO, a critical factor involved in sperm‐egg fusion, during IVF in pigs. We evaluated the numbers and acrosomal statuses of sperm binding to the ZP and oolemma, and being present in the ZP and perivitelline space (PVS) using ZP‐intact and ZP‐free oocytes. More sperm bound to the ZP than to the oolemma. The average number of sperm present in the PVS was 0.44?0.51 per oocyte, and all sperm had lost their acrosomes. The proportion of sperm that were immunopositive for anti‐IZUMO antibody was significantly higher after they were passing or had passed through the ZP. Furthermore, addition of anti‐IZUMO antibody to the fertilization medium significantly inhibited the penetration of sperm into ZP‐free oocytes. These results suggest that, in pigs, the ZP induces the acrosome reaction, which is associated with the functional exposure of IZUMO, resulting in completion of fertilization.     

Decreased blood cell counts were not observed in cattle living in the “difficult‐to‐return zone” of the Fukushima nuclear accident

White blood cells, especially lymphocytes, are susceptible to radiation exposure. In the present study, red blood cell, total white blood cell, and lymphocyte counts were repeatedly measured in cattle living on three farms located in the “difficult‐to‐return zone” of the Fukushima nuclear accident, and compared with two control groups from unaffected areas. Blood cell counts differed significantly between the two control groups, although almost all the values fell within the normal range. The blood cell counts of the cattle in the “difficult‐to‐return zone” varied across sampling times even on the same farms, being sometimes higher or lower than either of the two control groups. However, neither a statistically significant decrease in blood cell counts nor an increase in the rate of cattle with extremely low blood cell counts was observed overall. The estimated cumulative exposure dose for the cattle on the most contaminated farm was within a range of 500–1000 mSv, exceeding the threshold for the lymphopenia. Because of the low dose rate on these farms, potential radiation damages would have been repaired and have not accumulated enough to cause deterministic effects.     

Distribution of T cells in the Endometrium of the Mare 6 and 48 h after Insemination

Contents
In order to study the T-cell response after the introduction of semen into the uterine cavity, the distribution of helper T cells (CD4+) and cytotoxic/suppressor T cells (CD8+) was examined immunohistochemically in endometrial biopsy specimens. Endometrial tissue samples were obtained from 19 gynaecologically healthy mares during oestrus, both before and 6 or 48 h after deposition of a single dose of neat stallion semen. An increase (p = 0.04) in the numbers of helper T cells (CD4+) was observed at 6 h after insemination; thereafter the number of CD4+ cells decreased to pre-insemination values by 48 h after insemination. No significant variations in numbers of CD8+ cells were recorded either 6 or 48 h after insemination. There seems to be an early (6 h), recruitment of helper T cells into the equine endometrium after semen deposition, which might be related to the activation of the endometritis-like reaction seen as part of the equine uterine immune defence system during oestrus.     

Rabies Prevention and Management of Cats in the Context of Trap–Neuter–Vaccinate–Release Programmes

Domestic cats are an important part of many Americans' lives, but effective control of the 60–100 million feral cats living throughout the country remains problematic. Although trap–neuter–vaccinate–return (TNVR) programmes are growing in popularity as alternatives to euthanizing feral cats, their ability to adequately address disease threats and population growth within managed cat colonies is dubious. Rabies transmission via feral cats is a particular concern as demonstrated by the significant proportion of rabies post‐exposure prophylaxis associated with exposures involving cats. Moreover, TNVR has not been shown to reliably reduce feral cat colony populations because of low implementation rates, inconsistent maintenance and immigration of unsterilized cats into colonies. For these reasons, TNVR programmes are not effective methods for reducing public health concerns or for controlling feral cat populations. Instead, responsible pet ownership, universal rabies vaccination of pets and removal of strays remain integral components to control rabies and other diseases.