Description of swine producer biosecurity planning for foreign animal disease preparedness using the Secure Pork Supply framework.

Introduction: Preventing potential foreign animal diseases is a high priority, with re-emerging threats such as African Swine Fever emerging close to North American borders. The Secure Pork Supply (SPS) plan provides a voluntary framework for swine producer biosecurity planning and disease outbreak preparedness. However, biosecurity knowledge varies greatly among swine veterinarians, managers, and caretakers within the industry, which impacts the understanding, quality, implementation and biosecurity plan agreements with the SPS guidelines unless review procedures and quality control mechanisms are in place. Therefore, this study aimed to describe and identify the level of biosecurity planning agreements between producer-and/or swine veterinarian-made biosecurity plans for commercial swine sites and the SPS plan guidelines during a review process. Material and methods: Biosecurity maps (N = 368) and written plans (N = 247) were obtained from six Midwest swine companies/veterinary clinics. Maps were evaluated on accuracy and placement of mandatory map features based on SPS guidelines, and discrepancies between the development of producer-made biosecurity maps and written biosecurity plans. Multivariable mixed logistic regression analyses were conducted to identify differences in SPS planning accuracy based on herd size, production stage, and characteristics related to geographical site location (e.g., land cover type and expected feral swine population density in the region). Results: In this study, 55.8% (205/368) of all provided biosecurity maps had to be revised due to misplaced or missing map features. In addition, 80.9% (200/247) of the written plans had one or more conflicts with the corresponding biosecurity maps. The main biosecurity planning issues involved feed delivery activities, where the mapping of vehicle movements (89.9%, 222/247) were in direct conflict with the written SPS plans. Sites located in areas with a moderate expected feral swine population density had 3-fold increased odds of needing map revisions compared to sites with low expected feral swine population density. Sites located in predominately farmland had 7.3% lower odds of having biosecurity map and SPS plan conflicts for every 1.0% increase in farmland landcover in a 10-km radius around the swine site. Discussion: Human oversight or lack of knowledge regarding biosecurity planning and implementation is common, which may culminate in important preparedness shortcomings in disease prevention and control strategies for U.S. swine farms. Future efforts should focus on additional biosecurity training for swine producers and veterinarians alongside with quality control benchmarking of producer made plans.

Contrasting PRRSV temporal lineage patterns at the individual farm, production system, and regional levels in Ohio and neighboring states from 2017 to 2021.

Porcine reproductive and respiratory virus (PRRSV), one of the most significant viruses in the swine industry, has been challenging to control due to its high mutation and recombination rates and complexity. This retrospective study aimed to describe and compare the distribution of PRRSV lineages obtained at the individual farm, production system, and regional levels. PRRSV-2 (type 2) sequences (n = 482) identified between 2017 - 2021 were provided by a regional state laboratory (Ohio Department of Agriculture, Animal Disease Diagnostic Center (ODA-ADDL)) collected from swine farms in Ohio and neighboring states, including Indiana, Michigan, Pennsylvania, and West Virginia. Additional sequences (n = 138) were provided by one collaborating swine production system. The MUSCLE algorithm on Geneious Prime® was used to align the ORF5 region of PRRSV-2 sequences along with PRRSV live attenuated vaccine strains (n = 6) and lineage anchors (n = 169). Sequenced PRRSV-2 were assigned to the most identical lineage anchors/vaccine strains. Among all sequences (n = 620), 29.8% (185/620) were ≥ 98.0% identity with the vaccine strains, where 93.5% (173/185) and 6.5% (12/185) were identical with the L5 Ingelvac PRRS® MLV and L8 Fostera® PRRS vaccine strains, respectively, and excluded from the analysis. At the regional level across five years, the top five most identified lineages included L1A, L5, L1H, L1C, and L8. Among non-vaccine sequences with production system known, L1A sequences were mostly identified (64.3% - 100.0%) in five systems, followed by L1H (0.0% - 28.6%), L1C (0.0% - 10.5%), L5 (0.0% - 14.4%), L8 (0.0% - 1.3%), and L1F (0.0% - 0.5%). Furthermore, among non-vaccine sequences with the premise identification available (n = 262), the majority of sequences from five individual farms were either classified into L1A or L5. L1A and L5 sequences coexisted in three farms, while samples submitted by one farm contained L1A, L1H, and L5 sequences. Additionally, the lineage classification results of non-vaccine sequences were associated with their restriction fragment length polymorphism (RFLP) patterns (Fisher's exact test, p < 0.05). Overall, our results show that individual farm and production system-level PRRSV-2 lineage patterns do not necessarily correspond to regional-level patterns, highlighting the influence of individual farms and systems in shaping PRRSV occurrence within those levels, and highlighting the crucial goal of within-farm and system monitoring and early detection for accurate knowledge on PRRSV-2 lineage occurrence and emergence.

Investigating the uses of machine learning algorithms to inform risk factor analyses: The example of avian infectious bronchitis virus (IBV) in broiler chickens.

Infectious bronchitis virus (IBV) is a contagious coronavirus causing respiratory and urogenital disease in chickens and is responsible for significant economic losses for both the broiler and table egg layer industries. Despite IBV being regularly monitored using standard epidemiologic surveillance practices, knowledge and evidence of risk factors associated with IBV transmission remain limited. The study objective was to compare risk factor modeling outcomes between a traditional stepwise variable selection approach and a machine learning-based random forest Boruta algorithm using routinely collected IBV antibody titer data from broiler flocks. IBV antibody sampling events (n = 1111) from 166 broiler sites between 2016 and 2021 were accessed. Ninety-two geospatial-related and poultry-density variables were obtained using a geographic information system and data sets from publicly available sources. Seventeen and 27 candidate variables were screened to potentially have an association with elevated IBV antibody titers according to the manual selection and machine learning algorithm, respectively. Selected variables from both methods were further investigated by construction of multivariable generalized mixed logistic regression models. Six variables were shortlisted by both screening methods, which included year, distance to urban areas, main roads, landcover, density of layer sites and year, however, final models for both approaches only shared year as an important predictor. Despite limited significance of clinical outcomes, this work showcases the potential of a novel explorative modeling approach in combination with often unutilized resources such as publicly available geospatial data, surveillance health data and machine learning as potential supplementary tools to investigate risk factors related to infectious diseases.

Swine industry stakeholders' perception on the use of water-based foam as an emergency mass depopulation method.

The U.S. pork supply chain is vulnerable to various internal and external threats and in need of prompt, comprehensive response plans. Under urgent circumstances, for example in the case of foreign disease incursions, swine farms will have to perform on-farm animal depopulation to prevent disease spread. Several animal depopulation methods including water-based foam (WBF) have been proposed and are under evaluation for feasibility in the field. However, the psychological/emotional impacts of applying depopulation methods for personnel managing and carrying on the tasks are not currently well understood. Thus, this study aimed to investigate WBF as an alternative for depopulation compared to existing methods approved by the American Veterinary Medical Association. Swine industry stakeholders were invited to voluntarily observe a WBF depopulation trial and to provide their self-reported perspectives before and after the observation. A survey was designed to explore key areas on expected and perceived method effectiveness, efficiency, and animal welfare considerations, as well as to evaluate short-term post-observation psychological impacts. Among 42 recruited stakeholders, 31.0% (13/42) were educators/researchers followed by animal health officials (26.2%, 11/42) and veterinarians (23.8%, 10/42), with an average of 11.7 ± 12.6 (n = 39) years of work experience. After the trial, respondents' positive perception of WBF depopulation increased specifically regarding the animal loading process being less stressful than restrained in-barn depopulation options (P = 0.003) and by the observation of fewer swine escape attempts and vocalizations than expected (P < 0.001). Respondents' positive perception of WBF also increased regarding to the time required to fill the trailer with foam, to stop hearing animal vocalization, and stop hearing animal movement, as the observed trial times were faster than their pre-observation estimates (P < 0.001). Additionally, 79.5% (31/39) of respondents agreed that the rapid destruction of animal populations had priority over animal welfare under urgent scenarios. Minor post-traumatic stress disorder-like (PTSD-like) symptoms from the observed trials were reported (26.7%, 4/15 respondents) one month after the observation. This study showed that the WBF depopulation process was perceived positively by swine stakeholders and may have limited short-term psychological impacts on personnel involved in animal depopulation.

Space-Time Patterns of Poultry Pathogens in the USA: A Case Study of Ornithobacterium rhinotracheale and Pasteurella multocida in Turkey Populations.

Respiratory infections caused by Ornithobacterium rhinotrachealis (ORT) and Pasteurella multocida (PM) bacteria are significant threats to the poultry industry by causing economic losses and welfare issues. Due to characterization difficulties and underutilization of epidemiological tools, description of the spatio-temporal spread of these diseases in the field is limited. The objectives of this retrospective observational cross-sectional study were to (a) investigate the existence of space-time clusters (hotspots); and (b) investigate the association between genetic similarity and spatial proximity for both pathogens using molecular typing and a recently developed Core-Genome Multilocus Sequencing Typing (cgMLST) scheme. ORT (n = 103) and PM (n = 69) isolates from confirmed disease outbreaks from one commercial company between 2013 and 2021 were obtained from a veterinary diagnostic laboratory, characterized using a cgMLST scheme and visualized using a minimum spanning tree. Spatio-temporal cluster analysis using SaTScanTM and a Spearman's rank correlation were performed to investigate clustering and any association between allelic diversity and geospatial distance. The cgMLST sequencing revealed three allelic clusters for ORT and thirteen clusters for PM. The spatio-temporal analysis revealed two significant clusters for PM, one with a 259.3 km cluster containing six cases between May and July 2018 and a 9 km cluster containing five cases between February 2019 and February 2021. No spatio-temporal clusters were found for ORT. A weak negative correlation between allelic diversity and geospatial distance was observed for ORT (r = -0.04, p < 0.01) and a weak positive correlation was observed for PM (r = 0.11, p < 0.01). This study revealed regional spatio-temporal clusters for PM in commercial turkey sites between 2018 and 2021 and provided additional insight into bacterial strain subgroups and the geographical spread of ORT and PM over time.

Shelter dog behavior after adoption: Using the C-BARQ to track dog behavior changes through the first six months after adoption.

Despite millions of dogs entering and exiting shelters annually, little is known about dog behavior long-term after adoption. Entering a shelter is stressful for dogs which may inhibit or exaggerate behavior. There is a common public sentiment that dogs have a "honeymoon period" after adoption where dogs do not show their full repertoire of behaviors, both positive and negative, until getting more comfortable in their new home. The aim of this prospective observational cohort study was to identify prevalence of and changes in behavior issues in dogs throughout the first six months following adoption. The owners of ninety-nine dogs adopted from five Ohio shelters between October 1, 2020 and June 1, 2021 were surveyed 7, 30, 90, and 180 days after adoption, using the Canine Behavioral Assessment & Research Questionnaire (C-BARQ). Owners were also asked about household changes that may affect behavior. Estimated age, sex, weight, length of shelter stay, shelter intake reason, use of gastrointestinal, antibiotic, and psychotropic medications in the shelter, whether the animal had been previously returned to the shelter, and whether the owner was a first-time dog owner, were evaluated as predictors in a mixed effect regression model of different behavior measures over time. At various timepoints, dogs showed high prevalence for stranger-directed aggression (81.7%), owner-directed aggression (32.3%), dog-directed aggression (75%), familiar dog aggression (37.8%), stranger directed fear (58.2%), nonsocial fear (95.8%), dog directed fear (80.0%) and separation-related behaviors (92.6%). Over 180 days, stranger-directed aggression, excitability, touch sensitivity, training difficulty, and chasing increased, while separation-related behaviors, attachment and attention-seeking decreased. Owners reported high satisfaction with their dogs' behavior. Use of psychotropic medications in the shelter was predictive of stranger-directed aggression and touch sensitivity at home. These findings help veterinarians and shelter professionals council owners on potential behavior changes after adoption.

Refinement of water-based foam depopulation procedures for finisher pigs during field conditions: Welfare implications and logistical aspects.

Water-based foam (WBF) depopulation is currently being researched as an alternative for rapid destruction of swine populations under emergency circumstances. Appropriate guidelines are needed to maintain method reliability and depopulation efficacy while minimizing animal distress under field conditions. Finisher pigs were depopulated using WBF with a 7.5-minute dwell time in two trials to evaluate the effect of; trial 1) foam fill level (1.5, 1.75, or 2.0 times the pig's head height) and trial 2) foam fill rate (slow, medium, or fast) on aversive pig responses (surface breaks, vocalization, and escape attempts) and time to cessation of cardiac activity. Activity and cardiac activity were recorded using subcutaneous bio-loggers for swine in trial 2. The average time to cessation of movement (COM) from the start of foam filling was compared for the foam fill rate groups using a generalized linear mixed effect model under Poisson distribution. Foam rate group was used as an independent variable, and replicates as a random effect. For trial 1, the average (mm:ss ± SD) time to fill completion was 01:18 ± 00:00, 00:47 ± 00:05, and 00:54 ± 00:05, for 1.5, 1.75, and 2.0 times the pig's head height, respectively. For trial 2, the average time to fill completion was 03:57 ± 00:32, 01:14 ± 00:23 and 00:44 ± 00:03, and the average time (mm:ss ± SE) to COM was 05:22 ± 00:21, 03:32 ± 00:14, and 03:11 ± 00:13 for slow, medium, and fast fill rate groups, respectively. A higher number of aversive pig responses were observed for the lowest foam fill level and slowest foam fill rate compared to increased fill levels and faster fill rates. For trial 2 the median (mm:ss ± IQR) time to fatal arrhythmia was 09:53 ± 02:48, 11:19 ± 04:04, and 10:57 ± 00:47 post-foam initiation for fast, medium, and slow foam rate groups, respectively. Time to cessation of cardiac activity was significantly shorter for the fast foam rate group compared to medium and slow foam rates groups (P = 0.04). For both trials, vocalizations were absent, and all pigs were unconscious following the 7.5-minute dwell time and no pigs needed a secondary euthanasia method. This WBF study showed that slower fill rates and low foam fill levels may extend the time until cessation of cardiac activity in swine during depopulation. A conservative recommendation with consideration of swine welfare during an emergency scenario would be a minimum foam fill level twice the pig's head height and a foam fill rate capable of covering pigs in foam within 60 s to minimize aversive responses and expedite cessation of cardiac activity.

Water-based medium-expansion foam depopulation of adult cattle.

Current options for depopulation of adult cattle are limited, have logistic constraints, and may not be practical on a large scale. Aspirated water-based foam (WBF) has been shown to be successful in depopulating poultry and swine but has yet to be tested in cattle. WBF is advantageous because necessary equipment can be readily available, easy to use, and presents minimal personnel risk. With the use of a modified rendering trailer in a field setting, we evaluated the efficacy of aspirated WBF for depopulation of adult cattle. Water-based medium-expansion foam was added to the trailer holding cattle to a depth of approximately 50 cm greater than head height. The study was conducted as a gated design and the initial trial was conducted using six anesthetized and six conscious animals for verification of the process and followed by four replicates each containing 18 conscious cattle. A total of 84 cattle were used, with a subset (n = 52) implanted with subcutaneous bio-loggers that recorded activity and electrocardiograms. Cattle were loaded onto the trailer and three gasoline-powered water pumps delivered foam into the trailer followed by a 15-min foam dwell period. Average (± SD) time to completely fill the trailer with foam was 84.8 ±â€…11.0 s. No animal vocalizations were heard during foam application or the dwell period, and all cattle were confirmed dead upon removal from the trailer after 15 min of immersion. Necropsies of a subset of cattle revealed foam extending to at least the tracheal bifurcation in all cattle and distal to this level in 67% (8/12) animals. Time to cessation of movement, which served as a proxy for loss of consciousness, was 2.5 ±â€…1.3 min and time to cardiac death was 8.5 ±â€…2.5 min as determined by data from animals carrying subcutaneous bio-loggers. The results of this study indicate that WBF is a rapid and effective method for depopulation of adult cattle with potential advantages in speed and carcass handling and disposal over current methods.

Interactive euthanasia training program for the dairy industry: Implementation and perceived respondent knowledge change.

This study described the development of an interactive euthanasia training program and its potential to improve dairy workers' perceived euthanasia decision-making skills and awareness of timely euthanasia by using a survey instrument before and after the program. Training material encompassed euthanasia information over 2 production stages (calves and cows or heifers) and material was delivered on-farm in a case-scenario format (14 cases). During a 3-mo period, 30 different dairy farms were visited and 81 participants were enrolled in this study. Each participant was required to complete a survey pretraining, to complete the case studies from the production stage in which their job responsibility was more closely aligned with (estimated completion time of 1 h), and to complete a survey post-training. Surveys contained 8 statements regarding participants' perceived knowledge of euthanasia practices. The questions were answered on a 5-point scale: (1) strongly disagree, (2) disagree, (3) neither agree nor disagree, (4) agree, or (5) strongly agree. Multivariable mixed-effects logistic regression models were created for each question to investigate the effect of age, sex, dairy experience, farm size, role at the farm, race, previous experience with euthanasia, veterinarian degree, and production stage in the score change, defined by the presence or absence of an increase in the 5-point scale score. Upon completion of the training, respondents were more confident in identifying compromised animals (score change = 0.35), determining when an animal should be euthanized (score change = 0.64), and understanding the importance of timely euthanasia (score change = 0.26). Age and euthanasia experience were significantly associated with the respondents' perceived knowledge; suggesting that younger, less-experienced caretakers on-farm should be prioritized to receive training. The proposed interactive case-based euthanasia training program has proven to be valuable to dairy participants and veterinarians as it provides a means to improve dairy welfare.

Dairy workers' attitudes toward dairy cattle euthanasia.

Implementing timely and humane euthanasia in dairy farms remains a critical concern. One of the possible barriers for the implementation of timely euthanasia on-farm is dairy workers' attitudes toward the act. The objectives of this study were to investigate dairy workers' attitudes toward dairy cattle euthanasia and their association to individuals' demographic characteristics. A total of 81 workers from 30 dairy farms (ranging in size from less than 500 to more than 3,000 cows) participated in the survey and most participants were caretakers (n = 45; 55.6%) or farm managers (n = 16; 19.8%), with an average work experience of 14.8 years. Dairy workers' attitudes toward dairy cattle (empathy affect, empathy attribution, and negative attitudes about cattle), working environment (relying on others, perceived time constraints) and euthanasia decision-making (feeling comfortable with euthanasia, feeling confident, seeking knowledge, using different sources to obtain advice, having negative attitudes about euthanasia, having insufficient knowledge, having trouble deciding when to euthanize and avoiding if possible) were identified and used for cluster analyses. Cluster analyses identified 3 distinct clusters: (1) confident but uncomfortable with euthanasia (n = 40); (2) confident and comfortable with euthanasia (n = 32); and (3) unconfident, lacking knowledge and detached from cattle (n = 9). Dairy workers' demographic characteristics (age, sex, race and ethnicity, dairy experience, role on-farm, farm size, and previous euthanasia experience) were used as predictors for the risk factor analyses. The risk analysis demonstrated that there were no predictors for cluster 1, but White workers (P = 0.04) and caretakers that had previous euthanasia experience tended to be more likely to be members of cluster 2 (P = 0.07) whereas respondents that worked in farms with 501-1,000 cows were more likely to be grouped in cluster 3. This study provides vital information about variability in dairy workers' attitudes toward dairy euthanasia as well as its association with race and ethnicity, farm size, and previous euthanasia experience. This information can be used to implement appropriate training and euthanasia protocols to increase both human and dairy cattle welfare on-farm.

Description of electroencephalographic data gathered using water-based medium-expansion foam as a depopulation method for nursery pigs.

The United States' swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination protocols in place prior to pathogen introduction is paramount for business continuity and economic recovery. During extraordinary circumstances, it may become necessary to depopulate large populations of animals, including swine, as a disease containment measure. Currently approved depopulation methods for swine present significant logistical challenges when scaled to large populations or performed in field conditions. In the United States, water-based foam is currently approved for poultry depopulation, and recent field studies demonstrate water-based foam is an effective depopulation alternative for swine. While effective, the speed at which water-based foam induces loss of consciousness prior to death, a major welfare consideration, has not been adequately investigated. In this study, 12 nursery pigs were terminated using water-based medium-expansion foam to quantify the time to induce loss of consciousness and ultimately brain death. Each pig was implanted with subdermal electrodes to capture electroencephalographic data, placed in a body sling, and suspended in a plastic bulk container that was subsequently filled with water-based foam. Electroencephalographic data was recorded for 15 min, during which the pigs remained immersed in the water-based foam. Conservatively, average (± SD) time to unconsciousness and brain death was 1 min, 53 s ± 36 s and 3 min, 3 s ± 56 s, respectively. The relatively rapid loss of consciousness compared to other methods limits the amount of distress and is overall a positive finding for the welfare of the pigs that might be depopulated with water-based foam. The findings of this study add additional evidence supporting the use of water-based medium-expansion foam for an emergency depopulation of swine.

Characterizing the connection between swine production sites by personnel movements using a mobile application-based geofencing platform.

Biosecurity is critical to productivity and profitability in swine production systems and can be achieved by incorporating external (bioexclusion) and internal (biocontainment) practices. Although increasing threats of foreign animal diseases have justified the need of rigorous external biosecurity plans, their effectiveness highly depend on the compliance of on-farm employees, farm-related personnel, and visitors. In this study, we evaluated the uses of a mobile application-based geofencing platform in two swine production systems for accurately identifying personnel movements between swine production sites and detecting potential biosecurity breaches by violating required downtime between site visits. The geofencing platform accurately recognized 95.2% (379/398) of personnel entries comparing to physical entry logs. Further, among 1861 entries over a period of one month, 19 strongly connected components and 12 potential biosecurity breaches were identified. Personnel with duty in communications and information systems committed 75% of biosecurity breaches. The results reported herein demonstrated the possible uses of geofencing platforms for investigating connections among swine production sites by personnel movements and identifying biosecurity breaches.

Detection of Multiple Lineages of PRRSV in Breeding and Growing Swine Farms.

The detection and co-circulation of multiple variants of porcine reproductive and respiratory syndrome virus (PRRSV) have been observed and reported in swine. However, the potential long-term impact of multiple prevailing PRRSV variants on pig-performance is not yet fully understood. The primary objective of this study was to describe the genetic variation of PRRSV in processing fluid (PF), oral fluid (OF), and tonsil scraping (TS) specimens from five swine farms with different production types and PRRS status over a period of time (~1 year). Furthermore, the association between PRRSV prevalence and production parameters was investigated. Results showed that PRRSV was detected by RT-qPCR in 21-25% of all types of specimens. In breeding farms, PRRSV detection in PF and/or TS samples was correlated with stillborn and mummified fetuses, and pre-weaning mortality throughout the study period. Although ORF5 sequences were obtained in <16% of all sample types, simultaneous detection of PRRSV variants including field and vaccine strains within a single sampling event was identified in both breeding and growing pig farms. Phylogenetic analyses based on the ORF5 sequence classified the detected field PRRSV into L1A and L1H, two sub-lineages of lineage 1 (L1). Our study demonstrated the presence of multiple PRRSV lineages, sub-lineages, and variants in swine herds and its potential association with swine reproductive performance under field conditions.

Impact of transdermal flunixin administration on serum prostaglandin E2 and cortisol concentrations in piglets following castration.

OBJECTIVE: To assess the effects of transdermal flunixin administration on serum prostaglandin E2 (PGE2) and cortisol concentrations in piglets undergoing castration. ANIMALS: 104 litters with at least 4 male piglets/litter. PROCEDURES: Litters were randomly assigned to 1 of 4 treatments: transdermal flunixin (3.33 mg/kg) administration followed by surgical castration (CF; n = 28), transdermal flunixin administration followed by sham castration (SF; n = 26), application of physiologic saline solution followed by sham castration (S; n = 26), and application of physiologic saline solution followed by surgical castration (C; n = 24). Blood samples were collected 24 hours before and 1, 4, and 25 hours after castration or sham castration. RESULTS: Serum PGE2 concentrations for piglets in the C and CF groups did not differ at any time. Piglets in the S group tended to have higher serum PGE2 concentrations 1 hour after sham castration compared with piglets in the SF group. One hour after the procedure, piglets that underwent castration had higher serum cortisol concentrations than did piglets that underwent sham castration. Piglets in the CF group had higher serum cortisol concentrations than did piglets in the SF group 4 hours after the procedure, but serum cortisol concentrations did not differ between the C and S groups. CLINICAL RELEVANCE: Further studies are needed to explore dosing regimens, including effective doses and administration frequencies, and the pharmacokinetics of flunixin following transdermal administration in piglets undergoing castration.

Reliability of water-based medium-expansion foam as a depopulation method for nursery pigs and cull sows.

Animal disease preparedness plans including depopulation guidelines are paramount to prevent the spread of emerging infectious diseases but difficult to implement for swine under field conditions. However, water-based foam (WBF) is currently an approved and successfully deployed depopulation methodology in poultry. Therefore, the reliability of WBF as a depopulation method and the effectiveness and irreversibility of consciousness and consequential mortality in pigs of different ages was assessed across two trials. Trial 1 investigated the time to loss of consciousness and cessation of cardiac activity in nursery pigs (n = 72) at six different foam immersion time points (2.5, 5, 7.5, 10, 12.5 and 15 min) when placed in a 1.47 m3 (1.2 × 1.2 × 1.02 m, length × width × height) plastic bulk container. One pig per replicate was implanted with an ECG bio-logger. Irreversible loss of consciousness was observed after a 5-min immersion. The average (SD) time to development of a fatal arrhythmia from the initiation of the foam application was 7.3 min (1.82 s). Trial 2 aimed to validate the findings from Trial 1 in 75 larger cull sows across three replicates (n = 25). Sows were loaded into a 41-m3 sealed trailer (12.2 × 1.5 × 2.24 m), immersed in WBF and left undisturbed for 5 min post foam-filling completion. Six pigs in each replicate were implanted with an ECG bio-logger. A 5-min dwell time resulted in irreversible loss of consciousness and subsequent mortality in all cull sows. The average time (SD) to cessation of movement and fatal arrhythmia post foam-filling completion was 2.2 min (34.8 s) and 8.7 min (138.0 s), respectively. While a 5-min immersion in WBF induced irreversible loss of consciousness and death in both trials, a 7.5-min dwell time followed by observation for confirmation of death post WBF removal would be advisable for pigs of all sizes.

Investigation of the distance to slaughterhouses and weather parameters in the occurrence of porcine reproductive and respiratory syndrome outbreaks in U.S. swine breeding herds.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases affecting the swine industry. The main objective of this study was to assess whether sow farm distance to slaughterhouses and meteorological variables were associated with PRRS outbreaks. This case-control study paired 104 sow farms with or without a reported PRRS outbreak (N = 208) during the same period. Data on the distance to the closest slaughterhouse, swine density, presence of an air filtration system, or a neighboring farm, and weather conditions were collected, and a multivariable conditional logistic regression model was created to investigate the association between variables of interest and the occurrence of a PRRS outbreak. Swine density, presence of an air filtration system, presence of a neighboring farm, and PRRS herd-level status before the outbreak were associated with the occurrence of PRRS outbreaks. Farms in areas with higher swine density and nearby swine farms had increased odds of reporting an outbreak compared to farms in low swine density areas and farms having no neighbors. Under the conditions of this study, none of the meteorological variables or the distance to the closest slaughterhouse were associated with occurrence of PRRS outbreaks.

Enquête sur la distance aux abattoirs et les paramètres météorologiques dans l'apparition d'épidémies de syndrome reproducteur et respiratoire porcin dans les troupeaux reproducteurs de porcs aux États-Unis. Le syndrome reproducteur et respiratoire porcin (SRRP) est l'une des maladies les plus importantes sur le plan économique affectant l'industrie porcine. L'objectif principal de cette étude était d'évaluer si la distance entre les élevages de truies et les abattoirs et les variables météorologiques étaient associées aux épidémies de SRRP. Cette étude cas-témoin a apparié 104 élevages de truies avec ou sans éclosion de SRRP déclarée (N = 208) au cours de la même période. Des données sur la distance à l'abattoir le plus proche, la densité porcine, la présence d'un système de filtration d'air ou d'une ferme voisine et les conditions météorologiques ont été recueillies, et un modèle de régression logistique conditionnelle multivariable a été créé pour étudier l'association entre les variables d'intérêt et l'occurrence d'une épidémie de SRRP.La densité porcine, la présence d'un système de filtration de l'air, la présence d'une ferme voisine et le statut du troupeau relativement au SRRP avant l'épidémie ont été associés à l'apparition d'épidémies de SRRP. Les fermes situées dans des zones à forte densité porcine et d'autres fermes porcines à proximité avaient plus de chances de signaler une épidémie que les fermes situées dans des zones à faible densité porcine et les fermes sans voisins. Dans les conditions de cette étude, aucune des variables météorologiques ni la distance à l'abattoir le plus proche n'étaient associées à la survenue d'épidémies de SRRP.(Traduit par Dr Serge Messier).

Evaluation of a Water-Based Medium-Expansion Foam Depopulation Method in Suckling and Finisher Pigs.

The threat of foreign animal disease introduction through contaminated animal products, feed ingredients, and wildlife vectors have highlighted the need for additional approved methods for mass depopulation of swine under emergency scenarios, especially methods that can be applied to pigs across all production phases. The market disruption within the swine industry due to the SARS-CoV-2 pandemic has demonstrated this lack of preparation. The objective of this study was to validate water-based foam as a mass depopulation method for suckling (18 to 24 days of age) and finisher stage (63 to 100 days of age) pigs. Finisher pigs (n = 31, originally 32 but one finisher pig died prior to foaming), allocated as 9 triads and 1 set of 4 pigs, in 10 total replicates, and suckling pigs (n = 32), randomly allocated to two replicates, were completely covered in water-based medium-expansion foam for a 15-min dwell time in a bulk container. Container fill time for the trials were 6.5 ± 0.68 s and 5.3 ± 0.03 s for finisher and suckling pig replicates, respectively. Average (± SD) time for cessation of movement was 105 ± 39.1 s (s) for finisher pigs and 79.5 ± 10.5 s for suckling pigs. After completion of the 15-min dwell time in the foam, all pigs were confirmed dead upon removal from the container. The results from the present study suggest that the use of water-based foam can be an effective means of mass depopulation for suckling and finisher stage pigs, supporting previous research on the application to adult swine.

A longitudinal study on PRRSV detection in swine herds with different demographics and PRRSV management strategies.

Porcine reproductive and respiratory syndrome virus (PRRSV) has been one of the major health-related concerns in the swine production industry. Through its rapid transmission and mutation, the simultaneous circulation of multiple PRRSV strains can be a challenge in PRRSV diagnostic, control and surveillance. The objective of this longitudinal study was to describe the temporal detection of PRRSV in swine farms with different production types and PRRS management strategies. Tonsil scraping (n = 344) samples were collected from three breeding and two growing herds for approximately one year. In addition, processing fluids (n = 216) were obtained from piglet processing batches within the three breeding farms while pen-based oral fluids (n = 125) were collected in the two growing pig farms. Viral RNA extraction and reverse-transcription quantitative PCR (RT-qPCR) were conducted for all samples. The sample positivity threshold was set at quantification cycle (Cq) of ≤ 37. Statistical analyses were performed using generalized linear modelling and post hoc pairwise comparisons with Bonferroni adjustments using R statistical software. The results suggested a higher probability of detection in processing fluids compared to tonsil scraping specimens [odds ratio (OR) = 3.86; p = .096] in breeding farms whereas oral fluids were outperformed by tonsil scrapings (OR = 0.26; p < .01) in growing pig farms. The results described herein may lead to an improvement in PRRSV diagnostic and surveillance by selecting proper specimens.

Risk factors and impact of COVID-19-related clinic closures on the detection of gastrointestinal parasites in dogs, a cross-sectional study.

Infections with endoparasites, especially gastrointestinal helminths, are a common finding in client-owned dogs. The Community Practice section at the Ohio State University Veterinary Medical Center (OSU-VMC) follows Companion Animal Parasite Council, American Animal Hospital Association, and American Veterinary Medical Association guidelines for parasitology by recommending annual fecal analyses for dogs and prescribing year-round, broad-spectrum parasite preventatives. There is increasing interest in determining if parasite occurrence is changing in client-owned dogs. Therefore, a retrospective study was designed to examine risk factors associated with the detection of parasites in samples submitted to the OSU-VMC Clinical Veterinary Parasitology Diagnostic Laboratory. Of the 1198 canine fecal samples, 254 (21.2%) of these samples had a positive fecal analysis for gastrointestinal (GI) parasites. The age of the dog, time of year, reproductive status, purpose of fecal examination, GI signs, and type of parasite preventatives were assessed as potential risk factors for GI parasite infection in dogs. To determine if Coronavirus Disease 2019 (COVID-19)-associated hospital restrictions impacted the number of fecal examinations performed, data from January to December 2020, was compared to the same period in 2019. There was nearly a 50% reduction in canine fecal samples submitted to the OSU-VMC Clinical Veterinary Parasitology Diagnostic Laboratory in March 2020 compared to March 2019. At least one canine GI parasite was found in over 20% of all 1198 canine fecal samples (21.2%, 254/1198). The most commonly detected canine GI parasite in all the fecal samples was hookworm at 9.6% (115/1198), followed by Giardia sp. at 7.6% (91/1198). Age, use of parasite preventatives, breed, and reproductive status were found to be associated with parasite occurrence in the dog samples. Identifying such risk factors in dogs will guide veterinarians to advise annual fecal examinations more strongly to clients with high-risk dogs or when routine health visits are postponed for an extended period.