Ultrasonographically derived caudal vena cava parameters acquired in a standing position and lateral recumbency in healthy, lightly sedated cats: a pilot study

Objectives The aim of this study was to determine the feasibility of ultrasonographically measuring the caudal vena cava (CVC) at the subxiphoid view of healthy, lightly sedated cats in a standing position and lateral recumbency. Methods This was a prospective, observational, experimental single-centre study. Twenty healthy research-purposed cats were enrolled. Two trained operators scanned each cat in two positions – standing and lateral recumbency – in a randomised order. CVC diameter was measured at the narrowest diameter during inspiration and at the widest diameter during expiration, at two anatomical locations along the CVC – where the CVC crosses the diaphragm (base) and 2 mm caudal to the diaphragm. The CVC collapsibility index (CVC-CI) was calculated for each site. Normalcy was assessed with a Shapiro–Wilk test. A one-way ANOVA with post-hoc Tukey’s test was used to compare inspiratory with expiratory values within and between groups. A paired t-test compared the CVC-CI between groups ( P ⩽0.05 indicated statistical significance). Spearman’s correlation and Bland–Altman analysis assessed inter-operator variability. Results All ultrasonographic data passed normalcy and were reported as mean ± SD. When compared with each other, inspiratory and expiratory values were statistically different for position, location and operator (all P <0.0001). There was no statistically significant difference between lateral recumbency or standing position for inspiratory, expiratory and CVC-CI values. Inter-operator variability was substantial, with operator 2 consistently obtaining smaller measurements than operator 1. The mean CVC-CI in lateral recumbency at the base was 24% for operator 1 and 37% for operator 2. For the same site in standing position, CVC-CI was 27% and 41% for operators 1 and 2, respectively. Conclusions and relevance This pilot study demonstrates that it is possible to ultrasonographically measure the CVC diameter in both lateral recumbency and a standing position in healthy, lightly sedated cats. However, measurements obtained are operator dependent with variability between individuals. Further studies are needed to determine if ultrasonographic CVC assessment will prove helpful in estimating intravascular volume status in cats.

Anatomic characterization of the location of the esophageal ostium relative to the rima glottidis on CT in adult Labrador Retrievers

OBJECTIVE To characterize the anatomic location of the esophageal ostium relative to the rima glottidis in adult Labrador Retrievers with the use of CT. ANIMALS 98 CT scans of 75 adult Labrador Retrievers. PROCEDURES A search of the medical records database identified records of Labrador Retrievers that underwent CT of the head and neck between January 1, 2015, and December 31, 2018. Evaluators, blinded to each other's results, reviewed CT images and measured esophageal area at the level of the rima glottidis. For each dog, the left esophageal percentage (LEP) was calculated as the esophageal area left of the rima glottidis midline divided by the overall esophageal area at that level. Variables (age, sex, patient position, intubation status, and maxillary support during CT) were evaluated for association with LEP. The CT images of dogs that had multiple scans were assessed for within-patient variance. RESULTS Mean LEP was 56.2 ± 18.1% for all dogs. Only right lateral recumbency was significantly associated with LEP, with a lower LEP for dogs positioned in right lateral recumbency (42.4 ± 12.7%), compared with left lateral (63.0 ± 7.4%) or sternal (57.3 ± 18.8%) recumbency. No association was detected between LEP and other variables assessed. Eleven dogs had multiple CT scans; within-patient variance for LEP was ± 26.6%. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that, although most dogs had an LEP > 50%, the esophageal ostium was fairly centrally located in most dogs and may be more mobile than previously thought. Additional research is warranted to assess this mobility and whether the esophageal ostium location, relative to the larynx, affects the incidence of aspiration pneumonia in dogs undergoing surgical treatment for geriatric-onset laryngeal paralysis and polyneuropathy.

Bovine coenurosis

An 18-month-old mixed breed steer had incoordination, blindness, and opisthotonos for ten days. The clinical condition progressed to lethargy and lateral recumbency, and the steer was euthanized due to poor prognosis. There is a cyst located mainly on the left side of the brain, moderately distending the third ventricle and protruding through the transverse fissure into the right dorsal thalamic region anterior to the rostral colliculi. The cyst is 3.3 x 3.5 x 3 cm, consists of a thin transparent membrane filled with translucent fluid, and has numerous slightly elongated opaque white structures of approximately 1 mm (protoscolices) adhered to the inner aspect of the capsule (Fig. 1). The cyst causes compression and atrophy of the thalamus and hippocampus, more pronounced on the left side (Fig. 2). There is dilation of the lateral ventricles, moderate on the left side and mild on the right side. The mesencephalic aqueduct is moderately distended.

Horses’ Use of Lying Halls and Time Budget in Relation to Available Lying Area

Sleep is crucial to horses’ wellbeing, and their lying time can vary according to such factors as climate, exercise, bedding, and housing. This study aimed to analyze behavior and time spent in lying halls of various sizes. We examined the influence of housing systems on total lying time and behavior, and how changes to available lying area can affect lying time. Two open barns were used in this study, with lying areas of 8, 15, and 18 m2/horse available in the lying halls. The horses’ behavior was video recorded and logged using scan sampling and interval observations. Individual boxes were used as a control. The horses were found to spend longer time in sternal and lateral recumbency in the hall with a lying area of 18 m2/horse than the hall with a lying area of 8 m2/horse. Increasing the area of the lying hall also increased overall time spent there. Consequently, the hypothesis that increasing lying area will increase the horses’ use of the lying hall, as well as their total lying time, was accepted.

A Modified Approach for the Ultrasound-Guided Quadratus Lumborum Block in Dogs: A Cadaveric Study

Ultrasound-guided quadratus lumborum block (QLB) is a locoregional technique described in canine cadavers. The aim of this study was to assess a modified approach to QLB to minimise potential complications such as abdominal organ puncture. Nine canine cadavers were included and were positioned in lateral recumbency. An ultrasound-guided QLB was performed on each side. The probe was placed in the transverse position over the lumbar muscles just caudal to the last rib, and a needle was advanced in-plane from a dorso-lateral to a ventro-medial. A volume of 0.2 mL kg−1 of a mixture of iomeprol and methylene blue was injected. Computed tomography (CT) and dissection were performed to evaluate the spreading. Success was defined as staining of the nerve with a length of more than 0.6 cm. Potential complications such as intra-abdominal, epidural, or intravascular spreading of the mixture were also assessed. The CT images showed a T13 to L7 vertebra distribution, with a median of 5 (3–6). Dissection showed staining of the nerves from T13 to L4, with a median of 3 (2–5). No complications were found. This modified approach to QLB is safe and shows similar results to the previous studies in canine carcass.

Effects of Slaughter Positions on Catecholamine, Blood Biochemical and Electroencephalogram Changes in Cattle Restrained Using a Modified Mark IV Box

The proper slaughter positioning of animals is among the most crucial factors in animal welfare. The lateral position in Halal slaughter is a technique used around the world by Muslims, with a few practicing the upright position. The literature on the effects of slaughter in upright versus lateral positions on pain and stress is scarce. Thus, this study was designed to evaluate the effects of slaughter positions on blood biochemical parameters, plasma catecholamines, and electroencephalographic (EEG) responses. Twenty Brahman crossbred steers were subjected to slaughter in either lateral recumbency (LP) (n = 10) or an upright position (UP) (n = 10). There was a significant increase in adrenaline (p < 0.0001) and noradrenaline (p < 0.05) at T2 compared to T1 in the animals of both groups. A significant difference (p < 0.0001) was observed in the median frequency (MF) and total power (Ptot) of EEG, parameters for pain and stress, between the animals slaughtered in the upright and the lateral position. However, MF and delta waves were significantly higher (p < 0.05) after slaughter in the UP group than in the LP group. The results demonstrate a lesser amount of stress and pain responses among the LP group.

Parasitic encephalitis caused by Stephanurus dentatus in a pig in Brazil

A pig was in left lateral recumbency with limb spasticity, accentuated prostration, and strabismus, and was euthanized. During autopsy, yellowing of the leptomeninges at the ventral pons to medulla oblongata was noted. In the cerebellar peduncles, there was a focally extensive black-to-yellow area at the level of the vestibular nuclei. Histologic examination revealed a cross-section of a nematode larva, consistent with Stephanurus dentatus, bordered by edema and marked infiltration of mononuclear cells, plasma cells, and a few eosinophils. Vacuolation of the neuropil, with rare gitter cells and axonal spheroids, was also observed. We diagnosed parasitic encephalitis caused by S. dentatus migration based on the pathology findings and characterization of the parasite.

Xylazine or detomidine in dairy calves: a comparison of clinically relevant pharmacodynamic parameters under sedation

Objective Chemical restraint in dairy calves is necessary to enable diagnostic and surgical procedures. It is unclear whether xylazine or detomidine differ with regard to desirable and unwanted effects. Material and methods In a prospective randomized interventional study, 10 healthy Holstein-Friesian calves (age range 3–6 month) were sedated with either xylazine (0.1 mg/kg, Group X, n = 5) or detomidine (0.03 mg/kg, Group D, n = 5) intravenously, followed by butorphanol (0.1 mg/kg i. v.) in all animals. Characteristics of sedation and selected pharmacodynamic parameters were compared between groups using a non-parametric Mann-Whitney U test. Results All calves (5/5) in Group X and (3/5) calves in Group D became laterally recumbent within 5 minutes. Two calves (40 %) in Group D remained standing and could not been positioned in lateral recumbency 15 minutes after initial administration of the sedation agents. Sedation scores, onset and duration of sedation did not differ between groups. Heart and respiratory rate decreased in both groups. Mean arterial pressure was with around 30 mmHg significantly higher in Group D (t25, t30, t35, t40 with p = 0.018, 0.036, 0.029 and 0.016, respectively). In Group X, glucose level (t60) and packed cell volume (t30) were significantly lower (p = 0.032 and 0.048, respectively). Conclusion and clinical relevance The xylazine-butorphanol combination provided reliable recumbent chemical restraint. With detomidine-butorphanol recumbency failed in some individuals, but a sufficient clinical sedation was achieved. Based on the limited monitoring used in this study, the side effects are of minor clinical relevance in healthy individuals.