Outcome of video-assisted thoracoscopic treatment of idiopathic chylothorax in 15 cats.

OBJECTIVE: To evaluate the outcomes and complications of video-assisted thoracoscopic (VATS) treatment of chylothorax in cats. STUDY DESIGN: Multi-institutional retrospective study. ANIMALS: Fifteen client-owned cats. METHODS: The medical records of cats undergoing thoracoscopic thoracic duct ligation (TDL) for treatment of idiopathic chylothorax were reviewed. Cats undergoing additional procedures including thoracoscopic pericardectomy and/or laparoscopic cisterna chyli ablation (CCA)_were included. Follow up was obtained through communication with the referring veterinarian or owner. RESULTS: All cats underwent thoracoscopic TDL. Thirteen cats underwent simultaneous pericardectomy and two cats underwent laparoscopic CCA without pericardectomy. Conversion from a thoracoscopic to open approach was necessary in 2/15 (13%) of thoracic duct ligations and 1/11 (9%) of pericardectomies. The most common postoperative complication was persistent pleural effusion in five cats (33%). Four of 15 cats (27%) died or were euthanized prior to hospital discharge following surgery. Recurrence of effusion occurred in 1/7 (14%) of cats that sustained resolution of the effusion at the time of surgery with a median follow up of 8 months. The overall mortality attributed to chylothorax was 47%. CONCLUSION: Thoracoscopic treatment of idiopathic chylothorax resulted in a low incidence of intraoperative complications or conversion in the study population; however, mortality related to feline idiopathic chylothorax remained high. CLINICAL SIGNIFICANCE: While VATS treatment of idiopathic chylothorax is technically feasible, further consideration of the underlying pathology and current treatment algorithm is needed to improve outcomes as this remains a frustrating disease to treat in the feline population.

Skewness in bee and flower phenological distributions.

Phenological distributions are characterized by their central tendency, breadth, and shape, and all three determine the extent to which interacting species overlap in time. Pollination mutualisms rely on temporal co-occurrence of pollinators and their floral resources, and although much work has been done to characterize the shapes of flower phenological distributions, similar studies that include pollinators are lacking. Here, we provide the first broad assessment of skewness, a component of distribution shape, for a bee community. We compare skewness in bees to that in flowers, relate bee and flower skewness to other properties of their phenology, and quantify the potential consequences of differences in skewness between bees and flowers. Both bee and flower phenologies tend to be right-skewed, with a more exaggerated asymmetry in bees. Early-season species tend to be the most skewed, and this relationship is also stronger in bees than in flowers. Based on a simulation experiment, differences in bee and flower skewness could account for up to 14% of pairwise overlap differences. Given the potential for interaction loss, we argue that difference in skewness of interacting species is an underappreciated property of phenological change.

Sleep patterns, fatigue, and working hours among veterinary house officers: a cross-sectional survey study.

OBJECTIVE: To describe the sleep patterns, working hours, and perceptions of fatigue among veterinary house officers and to identify potential areas for targeted intervention to improve well-being. SAMPLE: 303 house officers. PROCEDURES: A 62-item questionnaire was generated by use of an online platform and sent to veterinary house officers at participating institutions via email. Responses were analyzed for trends and associations between variables of interest. RESULTS: The mean age of respondents was 30 ± 3.7 years. Participants included 239 residents and 64 interns. House officers slept significantly less during times when they had clinical responsibilities compared to off-clinic time (6.0 hours vs 7.5 hours, respectively; P < 0.01). The majority of house officers reported working 11 to 13 hours on a typical weekday (58% [174/302]), and 32% reported clinical responsibilities 7 d/wk. Working hours were negatively related to sleep quantity (Pearson correlation coefficient, -0.54; P < 0.01), and perceived sleep quality was worse when on call (P < 0.01). The majority of house officers felt that fatigue negatively interfered with their technical skills, clinical judgment, and ability to empathize to some extent in the previous 4 weeks. CLINICAL RELEVANCE: Most house officers fail to obtain sufficient sleep for optimal cognitive function and physical and mental health. Working hours and on call may be important factors contributing to the sleep patterns of veterinary house officers, and training program structure should be critically evaluated to promote protected time for sleep.

Veterinary house officer perceptions of dimensions of well-being during postgraduate training.

OBJECTIVE: To describe veterinary house officers' perceptions of dimensions of well-being during postgraduate training and to identify potential areas for targeted intervention. SAMPLE: 303 house officers. PROCEDURES: A 62-item questionnaire was generated by use of an online platform and sent to house officers at participating institutions in October 2020. Responses were analyzed for trends and associations between selected variables. RESULTS: 239 residents, 45 rotating interns, and 19 specialty interns responded to the survey. The majority of house officers felt that their training program negatively interfered with their exercise habits, diet, and social engagement. House officers reported engaging in exercise significantly less during times of clinical responsibility, averaging 1.6 exercise sessions/wk (SD ± 0.8) on clinical duty and 2.4 exercise sessions/wk (SD ± 0.9) when not on clinical duty (P < 0.001). Ninety-four percent of respondents reported experiencing some degree of anxiety regarding their physical health, and 95% of house officers reported feeling some degree of anxiety regarding their current financial situation. Overall, 47% reported that their work-life balance was unsustainable for > 1 year; there was no association between specialty and sustainability of work-life balance. Most house officers were satisfied with their current training program, level of clinical responsibility, and mentorship. CLINICAL RELEVANCE: Veterinary house officers demonstrated a poor balance between the demands of postgraduate training and maintenance of personal health. Thoughtful interventions are needed to support the well-being of veterinary house officers.

Behavioural responses by a bumble bee to competition with a niche-constructing congener.

While feeding, foragers can alter their environment. Such alteration constitutes ecological niche construction (ENC) if it enables future benefits for the constructor and conspecific individuals. The environmental modification may also affect non-constructing, bystander species, especially if they share resources with constructor species. If so, ENC could confer the constructor species a competitive advantage by both enhancing its foraging returns and reducing those of bystander species. Expectations - (E1) ENC frequency should vary positively with the recent and current density of the constructor species, and (E2) constructors should use modifications disproportionately. In contrast, bystanders should (E3) experience intensified competition for the affected resource, and (E4) exhibit diverse, possibly mitigating, responses to ENC, depending on opportunity and relative benefits. We investigated these expectations in Argentina for competition for Fuchsia magellanica nectar between an invasive bumble bee Bombus terrestris (terr: putative constructor), which often bites holes at the bases of floral tubes to rob nectar, and native B. dahlbomii (dahl: bystander), which normally accesses Fuchsia nectar through the flower mouth (front visits). Robbing holes constitute ENC, as they persist until the 7-day flowers wilt. The dynamics of the incidence of robbed flowers, abundance of both bees and the number and types of their flower visits (front or robbing) were characterised by alternate-day surveys of plants during 2.5 months. After initially accessing Fuchsia nectar via front visits, terr switched to robbing and its abundance on Fuchsia increased 20-fold within 10 days (E2). Correspondingly, the incidence of robbed flowers varied positively with recent and past terr abundance (E1). In contrast, dahl abundance remained low and varied negatively with the incidence of robbed flowers (E3). When terr ceased visiting Fuchsia, dahl abundance increased sixfold within 10 days (E3), possibly because many dahl previously had avoided competition with terr by feeding on other plant species (E4). While terr was present, dahl on Fuchsia used front visits (tolerance) or used existing robbing holes (adoption: E4). The diverse dahl responses suggest partial compensation for competition with terr. ENC alters competitive asymmetry, favouring constructor species. However, bystander responses can partially offset this advantage, perhaps facilitating coexistence.

Los animales pueden alterar su ambiente como consecuencia del forrajeo. Esta alteración constituye una forma de construcción de nicho ecológico (CNE) cuando la misma promueve beneficios para el constructor y otros individuos de la misma especie. Esta modificación ambiental puede también afectar otras especies no involucradas directamente en la CNE, especialmente cuando comparten recursos con la especie constructora. En este caso, la CNE puede conferir una ventaja competitiva a la especie constructora, incrementado sus beneficios alimenticios en detrimento de los de las especies no constructoras. Expectativas - (E1) La frecuencia de eventos de CNE debería variar positivamente con la densidad presente y pasada de la especie constructora, y (E2) los individuos de la especie constructora deberían usar las modificaciones asociadas a la CNE en forma diferencial. Por el contrario, los individuos de las otras especies que usen el mismo recurso deberían (E3) experimentar una intensificación de la competencia, y (E4) exhibir una diversidad de respuestas, algunas que atenúen las consecuencias negativas de la CNE, lo que va a depender de la oportunidad y de los beneficios relativos. En Argentina, investigamos el cumplimiento de estas expectativas en la competencia por el néctar de Fuchsia magellanica entre el abejorro invasor, Bombus terrestris (terr: la especie constructora), quien frecuentemente agujerea la base de tubos florales para robar néctar, y el abejorro nativo B. dahlbomii (dahl: la especie afectada), quien normalmente accede al néctar de Fuchsia en forma legítima a través de la apertura de la flor (visitas frontales). Los agujeros realizados por terr constituyen un caso de CNE, ya que persisten a lo largo de la vida de la vida de la flor (aprox. 7-day). En este trabajo relevamos la incidencia de flores robadas, la abundancia de las dos especies de abejas, y el número y tipo de sus visitas florales (frontales o de robo) día por medio durante 2.5 meses. Inicialmente terr accedió las flores de Fuchsia frontalmente, pero más tarde cambió su comportamiento convirtiéndose en un robador casi exclusivo a lo largo de un período de 10 días en que su abundancia se incrementó 20 veces (E2). En consecuencia, la incidencia de flores robadas varió positivamente con la abundancia de terr presente y pasada (E1). Por el contrario, la abundancia de dahl fue baja y varió negativamente con la incidencia de flores robadas (E3). En particular, la abundancia de dahl se incrementó seis veces en un período de 10 días una vez que terr cesó de visitar las flores de Fuchsia (E3), posiblemente porque dahl evitó la competencia con terr forrajeando en otras especies de plantas (E4). Cuando terr estuvo presente, dahl visitó las flores de Fuchsia frontalmente (tolerancia) o usó los agujeros existentes (adopción de comportamiento robador: E4). Estas respuestas diversas de dahl sugieren una compensación parcial de los efectos negativos de la competencia con terr. La CNE incrementa la asimetría de la competencia, favoreciendo la especie constructora. Sin embargo, las diferentes respuestas de las especies afectadas pueden compensar parcialmente esta desventaja competitiva, tal vez facilitando la coexistencia.

Earlier snow melt and reduced summer precipitation alter floral traits important to pollination.

Climate change can cause changes in expression of organismal traits that influence fitness. In flowering plants, floral traits can respond to drought, and that phenotypic plasticity has the potential to affect pollination and plant reproductive success. Global climate change is leading to earlier snow melt in snow-dominated ecosystems as well as affecting precipitation during the growing season, but the effects of snow melt timing on floral morphology and rewards remain unknown. We conducted crossed manipulations of spring snow melt timing (early vs. control) and summer monsoon precipitation (addition, control, and reduction) that mimicked recent natural variation, and examined plastic responses in floral traits of Ipomopsis aggregata over 3 years in the Rocky Mountains. We tested whether increased summer precipitation compensated for earlier snow melt, and if plasticity was associated with changes in soil moisture and/or leaf gas exchange. Lower summer precipitation decreased corolla length, style length, corolla width, sepal width, and nectar production, and increased nectar concentration. Earlier snow melt (taking into account natural and experimental variation) had the same effects on those traits and decreased inflorescence height. The effect of reduced summer precipitation was stronger in earlier snow melt years for corolla length and sepal width. Trait reductions were explained by drier soil during the flowering period, but this effect was only partially explained by how drier soils affected plant water stress, as measured by leaf gas exchange. We predicted the effects of plastic trait changes on pollinator visitation rates, pollination success, and seed production using prior studies on I. aggregata. The largest predicted effect of drier soil on relative fitness components via plasticity was a decrease in male fitness caused by reduced pollinator rewards (nectar production). Early snow melt and reduced precipitation are strong drivers of phenotypic plasticity, and both should be considered when predicting effects of climate change on plant traits in snow-dominated ecosystems.

Post-operative complications following apocrine gland anal sac adenocarcinoma resection in dogs.

Describe the complications associated with surgical resection of primary apocrine gland anal sac adenocarcinoma (AGASACA) tumours study design multi-institutional retrospective cross-sectional cohort study Animals Client owned dogs with spontaneous disease using the Clavien-Dindo classification system, post-operative events were assigned and described. Logistic regression analysis was used to analyse for risk factors for a significant association with complications. One hundred sixty-one dogs were included in the analysis. The post-operative sequelae, complication, and failure to cure rates specific to the anal sac site was 14%, 17% and 1%, respectively. The majority (68%) of complications were grade II or higher, therefore requiring some form of intervention. Intra-operative complications were identified in 11 cases (7%) with anorectal wall perforation being most common. An intra-operative complication was significantly associated with post-operative complications (p < 0.001; OR 7.4) while anorectal wall perforation was the only significant risk factor on regression analysis (p < 0.001; OR 19). Surgical site infection was identified in 20 of 161 (12%) of cases. Local recurrence (LR) occurred in 18% of cases at a median of 374 days (95% CI: 318-430). The only risk factor significantly associated with LR was the presence of vascular or lymphatic invasion (p = 0.008; OR 3). Post-operative complications were relatively infrequent but the risk was significantly increased when there was an intraoperative complication during resection of a primary AGASACA tumour. This study provides information for the clinician regarding risk factors for post-operative complications.

Surgical management and outcome of dogs with primary spontaneous pneumothorax: 110 cases (2009-2019).

OBJECTIVE: To describe surgical management and associated outcomes for dogs with primary spontaneous pneumothorax. ANIMALS: 110 client-owned dogs with primary spontaneous pneumothorax that underwent surgical management. PROCEDURES: Medical records at 7 veterinary teaching hospitals were reviewed. Data collected included signalment, history, clinical signs, radiographic and CT findings, surgical methods, intraoperative and postoperative complications, outcomes, and histopathologic findings. Follow-up information was obtained by contacting the referring veterinarian or owner. RESULTS: 110 dogs were included, with a median follow-up time of 508 days (range, 3 to 2,377 days). Ninety-nine (90%) dogs underwent median sternotomy, 9 (8%) underwent intercostal thoracotomy, and 2 (2%) underwent thoracoscopy as the sole intervention. Bullous lesions were most commonly found in the left cranial lung lobe (51/156 [33%] lesions) and right cranial lung lobe (37/156 [24%] lesions). Of the 100 dogs followed up for > 30 days, 13 (13%) had a recurrence of pneumothorax, with median time between surgery and recurrence of 9 days. Recurrence was significantly more likely to occur ≤ 30 days after surgery, compared with > 30 days after surgery. Recurrence > 30 days after surgery was rare (3 [3%]). No risk factors for recurrence were identified. CONCLUSIONS AND CLINICAL RELEVANCE: Lung lobectomy via median sternotomy resulted in resolution of pneumothorax in most dogs with primary spontaneous pneumothorax. Recurrence of pneumothorax was most common in the immediate postoperative period, which may have reflected failure to identify lesions during the initial thoracic exploration, rather than development of additional bullae.

Feasibility of thoracoscopic attenuation of the azygos vein as a model for portoazygos shunts: A canine cadaveric study.

OBJECTIVE: To evaluate the feasibility of thoracoscopic placement of three vascular attenuation devices by using the azygos vein as a model for portoazygos (PA) shunts and to describe the approach for thoracoscopic placement of these attenuation devices in small breed dogs. STUDY DESIGN: Randomized, prospective, cadaveric study. ANIMALS: Cadavers of 10 adult small breed dogs. METHODS: Cadavers were placed in sternal recumbency with left dorsolateral obliquity, and three thoracoscopic ports were established in the right hemithorax at the mid-10th intercostal space and dorsal third of the ninth and 11th intercostal spaces. The caudal azygos vein was thoracoscopically isolated along three adjacent segments bordered by four intercostal arteries, beginning just cranial to the first intercostal artery visualized cranial to the diaphragm. Three attenuation devices including coated cellophane, uncoated cellophane, and a 5-mm ameroid constrictor were thoracoscopically placed around one segment in each dog. Minor port access modifications were required to improve working space and triangulation in three dogs. Ability to successfully place the device, time required for placement, endoscopic clip configuration, and complications associated with placement were recorded. RESULTS: Median dog weight was 7.7 kg (range, 1.8-11). All attenuation devices were successfully placed thoracoscopically in all cadavers. No difference was detected in time required for placement between the ameroid constrictor and coated and uncoated cellophane (range, 2.3-33.8 minutes, P = .8). CONCLUSION: Ameroid constrictors and thin film bands were consistently placed via thoracoscopy around the caudal azygos vein of small breed dogs. CLINICAL SIGNIFICANCE: These results justify further investigation of thoracoscopic PA shunt attenuation in affected dogs.

Computed tomography in two recumbencies aides in the identification of pulmonary bullae in dogs with spontaneous pneumothorax.

Spontaneous pneumothorax presents a unique diagnostic and therapeutic challenge in veterinary medicine, specifically with regard to accurate identification of bullous lesions. Positioning of dogs with spontaneous pneumothorax during CT has not previously been evaluated. This retrospective, diagnostic accuracy study was performed to evaluate the sensitivity, positive predictive value (PPV), and interobserver variability for detection of pulmonary bullae with dogs positioned in multiple recumbencies. Dogs underwent CT in sternal and dorsal recumbency followed by thoracic exploration via median sternotomy. Three American College of Veterinary Radiology-certified veterinary radiologists blinded to surgical findings reviewed dorsal and sternal images simultaneously. Severity of pneumothorax, degree of atelectasis, lesion location and size, and view in which lesions were most confidently identified were compared to surgical and histologic findings. Sensitivities and PPVs for bulla detection ranged from 57.7% to 69.2% and 62.1% to 78.9%, respectively. For two of the 3 radiologists, the location of bullae in the thorax was significantly associated with the recumbency in which the lesion was best identified. Degree of atelectasis was found to be associated with the ability to identify lesions (P ≤ .02). The interobserver variability for identification was good (κ = 0.670). The sensitivity of CT when performed in both sternal and dorsal recumbency is similar to that previously reported. Because the distribution of bullae is unknown prior to advanced imaging and bulla location affects which recumbency is most useful for identification, acquisition of CT images in both sternal and dorsal recumbency may improve detection of bullous lesions and aid surgical planning.

Effect of Abscisic Acid (ABA) Combined with Two Different Beekeeping Nutritional Strategies to Confront Overwintering: Studies on Honey Bees' Population Dynamics and Nosemosis.

In temperate climates, beekeeping operations suffer colony losses and colony depopulation of Apis mellifera during overwintering, which are associated with biotic and abiotic stressors that impact bees' health. In this work, we evaluate the impacts of abscisic acid (ABA) dietary supplementation on honey bee colonies kept in Langstroth hives. The effects of ABA were evaluated in combination with two different beekeeping nutritional strategies to confront overwintering: "honey management" and "syrup management". Specifically, we evaluated strength parameters of honey bee colonies (adult bee and brood population) and the population dynamics of Nosema (prevalence and intensity) associated with both nutritional systems and ABA supplementation during the whole study (late autumn-winter-early spring). The entire experiment was designed and performed with a local group of beekeepers, "Azahares del sudeste", who showed interest in answering problems associated with the management of honey bee colonies during the winter. The results indicated that the ABA supplementation had positive effects on the population dynamics of the A. mellifera colonies during overwintering and on the nosemosis at colony level (prevalence) in both nutritional strategies evaluated.

The effect of enterococci on feline Tritrichomonas foetus infection in vitro.

Tritrichomonas foetus is a common cause of large bowel diarrhea in cats. Probiotics have been suggested to be effective for many intestinal pathogens; however, there are a lack of studies evaluating the effect of probiotics in T. foetus infection. In vitro studies were performed to evaluate the effect of a probiotic containing Enterococcus faecium (Efm) SF68 and a novel probiotic, Enterococcus hirae, on the inhibition of T. foetus growth, adhesion to, and cytotoxicity towards the intestinal epithelium. The effect of enterococci on T. foetus proliferation during co-culture was evaluated throughout log phase T. foetus growth. The previously validated in vitro co-culture model system using porcine intestinal epithelial cells (IPEC-J2) was used to evaluate the effect of enterococci on T. foetus adhesion and cytotoxicity towards intestinal epithelial cells. Cytotoxicity was assessed using fluorescent microscopy and spectrophotometry. Interactions of T. foetus, enterococci, and intestinal epithelial cells were assessed using scanning electron microscopy and immunofluorescence assays (IFA). Enterococcus-induced inhibition of T. foetus growth was demonstrated at concentrations as low as 104 enterococci colony forming units (CFU)/mL and was dependent, in part, on environmental pH and the presence of viable enterococci organisms. T. foetus adhesion, including with a ronidazole-resistant strain, was reduced with pretreatment of intestinal epithelial cells with enterococci but was not significantly affected when enterococci were introduced simultaneously or following T. foetus infection. Compared to Efm, E. hirae more effectively decreased T. foetus adhesion, suggesting its superior potential as a novel probiotic for T. foetus infection. There was no effect of enterococci treatment on T. foetus-induced intestinal epithelial cell cytotoxicity. Our results support further study into the investigation of a possible benefit of enterococci-containing probiotic treatment for prevention of T. foetus infection in at-risk uninfected cats.