Julie Arsenault

Background: After the identification of five novel feline erythrocyte antigens (FEAs) and evidence establishing FEA 1's immunogenicity, attempts to sensitize a cat to FEA 4 unexpectedly resulted in the production of alloantibodies directed against an unknown antigen, named FEA 6. Objectives: To estimate the prevalence of FEA 6 as a presumably new antigen, identify corresponding naturally occurring alloantibodies (NOAb), and investigate the associations between known FEAs. Animals: Two hundread and seven cats. Methods: Prospective blood typing for FEAs 1–6 was conducted in Type A cats (n = 193), followed by serial crossmatching in groups of 3–7 cats to detect NOAb and identify their target FEA. Agreement between FEA 6 blood typing and other FEAs was assessed. Associations between FEAs were evaluated to identify expression patterns. Results: Among 193 Type A cats, 67% were FEA 6-positive. Agreement analyses were supportive of FEA 6 being distinct from FEAs 1–5. NOAb were detected in 11 cats (5.7%), none of which were anti-FEA 6. Only FEA 1-negative status was significantly associated with the presence of NOAb (OR = 6.6, 95% CI, 1.9–23.1; p < 0.001). Significant associations were observed between the expressions of FEAs 1 and 4 (χ2 = 25.7, p < 0.001), and FEAs 3 and 5 (Fisher's exact test, p < 0.001), respectively. Conclusions and Clinical Importance: The immunogenicity and prevalence of the newly discovered FEA 6 raise concerns regarding its clinical relevance and role in posttransfusion sensitization. FEA 1/FEA 4 and FEA 3/FEA 5 pairs might belong to distinct antigenic systems.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial infections, including in veterinary settings. Hypothesis/Objectives: To investigate the prevalence, risk factors for Staphylococcus aureus (SA) and MRSA colonization, and the duration of MRSA colonization. Animals: Elective cases admitted to the Veterinary Teaching Hospital were recruited (228 horses). Methods: A cross-sectional study was conducted over 3 years. Nasal swabs were collected at admission and cultured for SA. Methicillin-resistant isolates were identified using matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) technology, oxacillin minimal inhibitory concentration (MIC), and PCR testing. Horses colonized with MRSA were resampled until two negative cultures were obtained. Stabling management, activity, and medical history were obtained from owners and medical files. Multivariable logistic regressions were used to model associations between risk factors and colonization. Results: The prevalence of SA and of MRSA nasal carriage was 17.5% (95% CI: 12.4–22.7) and 6.2% (95% CI: 2.9–9.4), respectively. Of the 10 horses colonized by MRSA and monitored over time, only one tested positive after 3 months. More than 10 horses on the premises (OR 6.0 – 95% CI 1.1–64.2), previous hospitalization (OR 6.0 – 95% CI 1.0–35.2), and year of admission (2022 vs. 2020–2021; OR 9.0 – 95% CI 1.7–92.2) were associated with MRSA nasal carriage. Conclusions and Clinical Importance: The prevalence of MRSA nasal colonization is of concern; however, the carriage seems transitory. Apart from the medical risk factors, the importance of social interactions in MRSA transmission needs to be elucidated in horses.

In Québec, Canada, nonreplacement calves are generally sent at a young age to auction markets to be sold for veal or dairy beef production. Various clinical observations found during the calves' journey, either at an auction market or on arrival at a calf raiser farm, have been associated with increased risk of morbidity, such as dehydration or umbilical problems. The objective of this cross-sectional study was to quantify associations between calf raising management strategies at the dairy farm level and clinical observations at auction markets during sale. For this purpose, during 8 different sale days, the 2 largest auction markets in Québec were visited, and all calves sold on those days were systematically examined. The number of clinically relevant findings (CRF) present per calf (among presence of umbilical cord, wet umbilical area, umbilical pain, umbilical swelling, persistent cervical skin fold ≥2 s, sunken eyes, eye or nasal discharge, ear drop, limb anomaly, emaciation or dirty hide) was recorded. After the sale, farm owners were contacted to answer a specific questionnaire on calf management. The total number of CRF from all sold calves from the same farm (dependent variable) was modeled using Poisson multivariable regression, with questionnaire answers as potential covariates and the number of calves sold per farm during the observation period as an offset. The questionnaire was completed during a standardized phone call and focused on farm characteristics and characteristics of calves sold, including calving management, calf care at birth, nutrition, housing, and transportation. A total of 3,656 calves from 1,349 different sellers were examined. The questionnaire information was obtained from 409 different farms representing 847 calves. The median number of calves sold per farm was 2 (range: 1-19). The umbilical cord was visually present in 376 calves (44%). Among the most commonly observed CRF, eye discharge (n = 290, 34%), umbilical swelling (n = 144, 17%), and presence of dehydration signs (persistent cervical skin fold ≥2 s [n = 111, 13%] or sunken eyes [n = 83, 9.8%]) were the most commonly reported anomalies. According to the final multivariable Poisson regression model, the incidence rate ratio (IRR) of CRF for farms that sold calves at a mean age 10 d (IRR = 1.21, 95% CI: 1.04-1.41). The IRR was also higher for farms that did not give colostrum to calves within 1 h following birth compared with calves receiving colostrum within 1 to 2 h (IRR = 1.73, 95% CI: 1.24-2.49), 2 to 6 h (IRR = 1.48, 95% CI: 1.06-2.14) and more than 6 h (IRR = 1.59, 95% CI: 1.06-2.44) after birth. The IRR were higher for farms using milk replacer to feeding sold calves versus raw milk (IRR = 1.2, 95% CI: 1.06-1.37) and higher for farms where calves typically receive their last meal >3 h before transportation to the auction market versus calves receiving their last meal <1 h before transportation (IRR = 1.26, 95% CI: 1.04-1.53). This study provides interesting insight into farm practices that are associated with an improved clinical status of nonreplacement calves sold at auction markets for veal and beef meat.

Each year ∼150,000 surplus calves are sold at auction markets in Québec, Canada. Surplus calves (male or female not kept in the herd of origin) are sold at a young age, but these animals are at risk of receiving lower quality neonatal care than replacement heifers. Knowledge of factors associated with a higher selling price could help convince farmers to spend more resources in the care surplus calves. Our objective was to explore the associations between farm management practices and the median percentile of surplus calf selling price per farm at auction markets. The price (Canadian dollars/kg of BW) and the individual identification number of surplus calves sold in 2 auction markets in Québec during 4 sale days in the summer 2019 and in the winter 2020 were recorded. The recorded price of each surplus calf was transformed as percentile for each breed and day of sale. Farmers managing the surplus calves were contacted and interviewed on farm management practices. The data from farmer's interviews were analyzed as potential variables associated with the median percentile of calves' selling price per farm (farm-level dependent variable) in a multivariable linear regression model. A total of 509 farmers were contacted, of which 433 farmers agreed to participate, and 409 interviews were retained for statistical analysis. The farms enrolled in the study had sold a median of 2 calves (range 1-19 calves) during the sale days considered. The main breed of surplus calves sold were Holstein (82%) and Angus crossbred calves (9%). The results from the multivariable model showed that median percentile of calves' selling price was positively associated with farms with an average milk production per cow superior to 11,000 L/yr (β 0.13, 95% CI: 0.045, 0.221) and farms with 3 or more workers available to take care of surplus calves (β 0.08, 95% CI: 0.005, 0.167). Those results indicate that farms having an average milk production per cow superior to 11,000 L/yr increase the calves' selling price by 13 percentiles (i.e., from 50th to 63rd) and that farms having at least 3 caretakers increase their median percentile calves' selling price by 8 percentiles (i.e., from 50th to 58th). Median percentile of calves' selling price was negatively associated with farms that vaccinated cows for neonatal calf diarrhea (β -0.06, 95% CI: -0.127, -0.011), that do not disinfect the navel of newborn calves (β -0.07, 95% CI: -0.133, -0.012), that allow transporters to enter the farm's building (β -0.07, 95% CI: -0.130, -0.015) and that used wood shaving as bedding for surplus calves (β -0.08, 95% CI: -0.156, -0.021). Sensitivity analyses performed on farms that have sold 2 or more surplus calves did not show significant changes in the associations found. Despite the fact that the study was based on self-reported questionnaire answers and a small number of calves per farm, it provides insight on farm management practices associated with median percentile of surplus calf selling price at the auction markets. Taking these results in consideration, farmers could potentially improve the market value of their animals.

Echinococcus spp. is an emerging zoonotic parasite of high concern. In Canada, an increase in the number of human and animal cases diagnosed has been reported, but information regarding the parasite’s distribution in wildlife reservoir remains limited. A cross-sectional study was conducted to estimate the prevalence of wild canids infected with Echinococcus spp. and Echinococcus multilocularis in areas surrounding populated zones in Québec (Canada); to investigate the presence of areas at higher risk of infection; to evaluate potential risk factors of the infection; and as a secondary objective, to compare coproscopy and RT-PCR diagnostic tests for Taenia spp. and Echinococcus identification. From October 2020 to March 2021, fecal samples were collected from 423 coyotes (Canis latrans) and 284 red foxes (Vulpes vulpes) trapped in 12 administrative regions. Real-time PCR for molecular detection of genus Echinococcus spp. and species-specific Echinococcus multilocularis were performed. A total of 38 positive cases of Echinococcus spp., of which 25 were identified as E. multilocularis, were detected. Two high-risk areas of infection were identified. The prevalence of Echinococcus spp. was 22.7% (95% CI 11.5–37.8%) in the Montérégie centered high-risk area, 26.5% (95% CI 12.9–44.4%) in the Bas-St-Laurent high-risk area, and 3.0% (95%CI 1.8–4.7%) outside those areas. For E. multilocularis, a prevalence of 20.5% (95% CI 9.8–35.3%) was estimated in the high-risk area centered in Montérégie compared to 2.4% (95% CI 1.4–3.9%) outside. Logistic regression did not show any association of infection status with species, sex, or geolocation of capture (p > 0.05). This study shows the circulation of Echinococcus in a wildlife cycle in 9/12 administrative regions of Québec.

Winter mortality of honey bee colonies represents a major source of economic loss for the beekeeping industry. The objectives of this prospective study were to estimate the incidence risk of winter colony mortality in southwestern Quebec, Canada and to evaluate and quantify the impact of the associated risk factors. A total of 242 colonies from 31 apiaries was selected for sampling in August 2017. The presence of Varroa destructor, Vairimorpha (Nosema) spp., Melissococcus plutonius, deformed wing virus (DWV), and viruses of the acute-Kashmir-Israeli complex (AKI complex) was investigated in each colony. Management practices of the various colonies were obtained from a questionnaire. The incidence risk of colony mortality during the winter of 2017-2018 was estimated to be 26.5% [95% confidence interval (CI): 15.4 to 40.3]. In logistic regression modeling of winter mortality in colonies, an interaction was discovered between V. destructor and DWV; the detection of >= 1 V. destructor mites per 100 bees was associated with higher odds of mortality (3.46, 95% CI: 1.35 to 8.90) compared to colonies with < 1 mite per 100 bees, but only in DWV-positive colonies. There were more colony losses in apiaries from beekeepers owning 1 to 5 colonies than in apiaries from beekeepers owning over 100 colonies, which suggests that beekeeper experience and/or type of management are important contributors to winter colony mortality. Assuming a causal relationship, the results of this study suggest that up to 9% of all colony mortalities in the population could have been prevented by reducing the level of V. destructor to < 1 mite per 100 bees in all colonies.

Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern Quebec to: i) estimate the prevalence of 11 bee pathogens; ii) assess the agreement between beekeeper suspicion of a disease and laboratory detection of the causative pathogen; and iii) explore the association between observed clinical signs and pathogen detection in a colony. A total of 242 colonies in 31 apiaries owned by 15 beekeepers was sampled in August 2017. The prevalence of Varroa destructor detection was estimated as 48% for colonies and 93% for apiaries. The apparent prevalence of colonies infected by Nosema spp. and Melissococcus plutonius was estimated as 40% and 21%, respectively. At least 180 colonies were tested by polymerase chain reaction (PCR) for deformed wing virus (DWV), acute-Kashmir-Israeli complex (AKI complex), and black queen cell virus (BQCV), which were detected in 33%, 9%, and 95% of colonies, respectively. Acarapis woodi, Paenibacillus larvae, and Aethina tumida were not detected. Varroasis was suspected by beekeepers in 14 of the 15 beekeeping operations in which the mite was detected. However, no correlation was found between suspected European foulbrood and detection of M. plutonius or between suspected nosemosis and detection of Nosema spp. Colony weakness was associated with Nosema spore counts of at least 0.5 x 10(6) per bee. Melissococcus plutonius was more frequently detected in colonies showing scattered brood.

Salmonella Dublin and Campylobacter spp. are two foodborne pathogens of importance. A small number of studies reported that consumption of veal liver was associated with an increased risk of human illness from these two pathogens. To better characterize the risk of exposure from liver, a cross-sectional study was conducted to estimate the prevalence of white veal calf liver contamination with these two pathogens and to characterize the antimicrobial non-susceptibility patterns of isolates. Veal liver samples were collected at two slaughterhouses in Quebec, Canada, in 2016 and 2017. Samples were submitted for polymerase chain reaction (PCR) screening followed by culture of Salmonella and thermotolerant Campylobacter. Isolates were tested for antimicrobial susceptibility using broth microdilution. Salmonella Dublin was the only serotype cultured from 3.6% (95% confidence interval [CI]: 0.0–7.9) of 560 liver samples. Among them and for technical reasons, 498 were tested by PCR for Campylobacter. The prevalence of PCR-positive livers was estimated to be 65.8% (95% CI: 58.7–72.9) for Campylobacter jejuni and 7.0% (95% CI: 3.9–10.1%) for Campylobacter coli. Fourteen Salmonella Dublin isolates were submitted for antimicrobial resistance (AMR) testing; all were non-susceptible to at least eight antimicrobials from six different classes. Most (81.4%) of the 188 C. jejuni isolates submitted for AMR testing were non-susceptible to tetracycline, and 23.0% of isolates were non-susceptible to nalidixic acid and ciprofloxacin. Of the seven C. coli isolates, four were multidrug resistant. This study highlights the importance of veal liver as a potential source of exposure to multidrug-resistant Salmonella Dublin and thermotolerant Campylobacter spp.