Western College of Veterinary Medicine

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2021 Videocast by Dr. Hiroo Suami: Anatomical Studies of the Lymphatic System - Comparative Anatomy between Canine and Humans
(University of Saskatchewan Pressbooks, 2021-08-24) Suami, Hiroo
A neglected and emerging antimicrobial resistance gene encodes for a serine-dependent macrolide esterase
(PNAS, 2023-02) Dhindwal, Poonam; Thompson, Charis; Kos, Daniel; Planedin, Koa; Jain, Richa; Jelinski, Murray; Ruzzini, Antonio
The accumulation of antimicrobial resistance genes (ARGs) in specific environments, and eventually in pathogens, challenges the utility of antibiotics. Thousands of ARGs and resistance-conferring mutations are known and accessible in curated databases. Nevertheless, our catalog of ARGs is incomplete. Blind spots—novel and unreported ARGs—pose unknown risks to human health, animal wellness, and the sustainability of agriculture. A novel and unreported ARG is one that cannot be identified by homology-based inference. These unknown genes are absent from the ARG databases that serve antimicrobial resistance (AMR) surveillance programs intended to inform clinical practice. Growing concerns related to antimicrobial use and efficacy prompted us to evaluate watering bowls as sentinel systems for ARG detection at a beef cattle feedlot. The identification and functional characterization of a neglected ARG that resulted form the basis of this report.
Antimicrobial Disc Diffusion Testing - A Visual Guide
(2024-05-29) Rubin, Joseph E; Weerasooriya, Gayani; Madalagama Appuhamilage, Roshan Priyantha
Avian influenza virus circulation and immunity in a wild urban duck population prior to and during a highly pathogenic H5N1 outbreak
(Veterinary Research, 2024-11) Wight, Jordan; Rahman, Ishraq; Wallace, Hannah; Cunningham, Joshua; Roul, Sheena; Robertson, Gregory J; Russell, Rod; Xu, Wanhong; Zhmendak, Dmytro; Alkie, Tamiru N.; Berhane, Yohannes; Hargan, Kathryn; Lang, Andrew S.
Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b viruses were first detected in St. John’s, Canada in late 2021. To investigate the patterns of avian influenza virus (AIV) infection and immune responses subsequent to the arrival of H5N1, we sampled the wild urban duck population in this area for a period of 16 months after the start of the outbreak and compared these findings to those from archived samples. Antibody seroprevalence was relatively stable before the outbreak (2011–2014) at 27.6% and 3.9% for anti-AIV (i.e., NP) and H5-specific antibodies, respectively. During the winter of 2022, AIV-NP and H5-specific antibody seroprevalence both reached 100%, signifying a population-wide infection event, which was observed again in late February 2023 following a second H5N1 incursion from Eurasia. As expected, population-level immunity waned over time, with ducks seropositive for anti-AIV-NP antibodies for approximately twice as long as for H5-specific antibodies, with the population seronegative to the latter after approximately six months. We observed a clear relationship of increasing antibody levels with decreasing viral RNA loads that allowed for interpretation of the course of infection and immune response in infected individuals and applied these findings to two cases of resampled ducks to infer infection history. Our study highlights the value of applying both AIV surveillance and seroprevalence monitoring to provide a better understanding of AIV dynamics in wild populations, which may be crucial following the global dissemination of clade 2.3.4.4b H5Nx subtypes to assess the threats they pose to both wild and domestic animals, and to humans.
Avulsion of the lateral origin of the gastrocnemius muscle mimicking cranial cruciate ligament deficiency in a dog
(Vet Record Case Reports, 2023-12) Zadeh, Abedin Shaban; Boston, Sarah Elizabeth
Avulsion of the lateral head of the gastrocnemius is an uncommon diagnosis. Nonetheless, it is a possible cause of lameness in dogs, and it could be misdiagnosed as a cranial cruciate ligament injury if a systematic approach to clinical case management is not followed. The treatment of choice for avulsion of the gastrocnemius is surgical stabilisation. The proximity to the peroneal nerve and scarcity of bone for purchase for stabilisation are surgical challenges. However, the stabilisation by a spiked washer and screw can yield an excellent outcome for return to function.
Contouring the canine optic apparatus using the optic plane
(2022) Walther, Eric
Contouring the canine optic apparatus using the optic plane
(2022) Walther, Eric; Mayer, Monique
Course Notes - Veterinary Bacteriology and Mycology
(2024) Rubin, Joseph E
Welcome to microbiology! In this 3-credit unit course we will cover the microbiology of bacterial and fungal organisms of importance to veterinary medicine. This content of this course lies somewhere in between basic microbiology and clinical infectious disease; although we will discuss some fundamental microbiological concepts, material will be presented from the clinician’s perspective where possible.
Dioctophyme renale (giant kidney worm) in a dog: A review of a parasitic disease requiring surgical treatment
(Vet Record Case Reports, 2025-01) Zadeh, Abedin Shaban; Carr, Anthony P; Jenkins, Emily J
Infection with the nematode Dioctophyme renale (giant kidney worm) in dogs and other mammals occurs following the ingestion of an aquatic host containing the infective larvae. This parasitic disease has no known effective pharmaceutical treatment. This case report describes a 7-month-old, entire, female Husky with a 2-month history of haematuria and intermittent vomiting. An abdominal ultrasound examination and microscopic finding of eggs of D. renale in urine sediment helped to establish the diagnosis. The affected right kidney and retroperitoneal worms were removed by exploratory celiotomy. The sonographic features of the worms and a comprehensive review of the latest literature, suggesting future research topics on early serological diagnosis, medical treatment options and the most recent nephron-sparing nephrotomy techniques (via nephroscopy or laparoscopy), are discussed.
Exploring the effect of play on heart rate variability as a measure of positive emotional states in pigs
(Frontiers in Veterinary Science, 2025-01) Steinerová, Karolína; Krause, Annika; Parker, Sarah E; Seddon, Yolande Maria
Play behaviour has been suggested to be inherently rewarding for animals, inducing positive emotional states. The psychophysiological effect of emotions can be assessed through heart rate variability (HRV), serving as a proxy measure of sympathovagal balance. This study investigated how the performance of play influences heart rate (HR) and HRV parameters (RMSSD, SDNN) in pigs. It was hypothesized that HRV would increase during and immediately after play due to predominant vagal activation compared to baseline, indicating a positive emotional state. Gilts (n = 32, 18 and 19 weeks of age), housed in standard partly-slatted pens, were selected from two pen-level play treatments: Novelty (NOV) and Play Pen (PLP). Play treatment pigs were reared with intermittent play promotion (3x/week) from 10 weeks of age. For HRV recordings, play was promoted for 15-min in pairs of gilts within treatment, with destructible novel objects given either in the home pen (NOV, 1 m2/pig), or in an enclosed ‘playpen’ area providing extra space (PLP, 2.9 m2/ pig). HRV was measured during a play session in three consecutive periods: (i) baseline (before play bout, no play occurring), (ii) play bout (play expression), and (iii) after-play (immediately after play bout). Twenty-six gilts played at least once. Play bouts lasted between 10 and 30 s (10 s: n = 60, 20 s: n = 18, 30 s: n = 6). In 10-s bouts, compared to baseline, RMSSD was higher during play (p = 0.027) and after-play (p = 0.015), while SDNN increased during play (p ≤ 0.001) and after-play (p = 0.008) only with ambulation (pig moving forward: walking or running). HR did not differ across periods but was higher at ambulation (p = 0.003). Twenty-sec bouts followed the same relationship with only numerical differences, while HRV in 30-s bouts did not differ. Treatments did not influence HRV. Results suggest that engaging in play increases HRV, with this effect persisting into the period immediately after play. This indicates that play contributes to positive emotional states in pigs. Physical activity involved in play influences HRV. More dynamic and energetic play involving ambulation might be more rewarding for pigs. This study provides evidence for assessing positive emotions in pigs and underscores the importance of incorporating rewarding experiences into conventional farming practices.
Frequency and antimicrobial susceptibility of Staphylococcus aureus isolated from clinical bovine mastitis cases in British Columbia, Canada
(Journal of Veterinary Diagnostic Investigation, 2024-12-26) Leon, Melissa; Rubin, Joseph; Raverty, Stephen; Ghosh, Kazal
Staphylococcus aureus is one of the most important bacteria responsible for clinical bovine mastitis globally, leading to significant economic losses in the dairy industry. Antimicrobials used to treat and prevent mastitis can lead to antimicrobial resistance (AMR) in S. aureus. We retrospectively evaluated AMR of S. aureus isolates from clinical bovine mastitis cases submitted to the Animal Health Centre in British Columbia from 2013 to May 2024. S. aureus was isolated from 15.0% of submitted bovine milk samples. Antimicrobial susceptibility testing was done on 611 of 1,347 S. aureus isolates. No methicillin-resistant S. aureus isolates were detected based on cefoxitin susceptibility test results, which is encouraging. The highest frequencies of resistance were found for penicillin (46.6%) and ampicillin (42.1%). The lowest frequencies of resistance were to ceftiofur and sulfamethoxazole–trimethoprim (0.2% each) and cephalothin (0.3%). AMR trends over our study period were generally stable, except for penicillin and ampicillin; penicillin resistance increased from 15.2% to 71.1%, and ampicillin resistance increased from 18.2% to 70.1%. The information in our study could help guide clinicians when choosing antimicrobial treatments to treat mastitis caused by S. aureus, particularly in the province of British Columbia. Because S. aureus has a broad host range and is of importance to both human and veterinary medicine, continued monitoring to detect the emergence of resistance is warranted.
From bees and bison to vaccines and medical imaging
(AVMA Publications, 2022-12-28) Muir, Gillian; MacDonald, Myrna
How Does African Swine Fever Virus Evade the cGAS-STING Pathway?
(Pathogens, 2024-11) Lin, Can; Zhang, Chenyang; Chen, Nanhua; Meurens, Francois; ZHU, JIANZHONG; Zheng, Wanglong
African swine fever (ASF), a highly infectious and devastating disease affecting both domestic pigs and wild boars, is caused by the African swine fever virus (ASFV). ASF has resulted in rapid global spread of the disease, leading to significant economic losses within the swine industry. A significant obstacle to the creation of safe and effective ASF vaccines is the existing knowledge gap regarding the pathogenesis of ASFV and its mechanisms of immune evasion. The cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a major pathway mediating type I interferon (IFN) antiviral immune response against infections by diverse classes of pathogens that contain DNA or generate DNA in their life cycles. To evade the host’s innate immune response, ASFV encodes many proteins that inhibit the production of type I IFN by antagonizing the cGAS-STING signaling pathway. Multiple proteins of ASFV are involved in promoting viral replication by protein–protein interaction during ASFV infection. The protein QP383R could impair the function of cGAS. The proteins EP364R, C129R and B175L could disturb the function of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). The proteins E248R, L83L, MGF505-11L, MGF505-7R, H240R, CD2v, E184L, B175L and p17 could interfere with the function of STING. The proteins MGF360-11L, MGF505-7R, I215L, DP96R, A151R and S273R could affect the function of TANK Binding Kinase 1 (TBK1) and IκB kinase ε (IKKε). The proteins MGF360-14L, M1249L, E120R, S273R, D129L, E301R, DP96R, MGF505-7R and I226R could inhibit the function of Interferon Regulatory Factor 3 (IRF3). The proteins MGF360-12L, MGF505-7R/A528R, UBCv1 and A238L could inhibit the function of nuclear factor kappa B (NF-Κb).
Identification of genetic markers of resistance to macrolide class antibiotics in Mannheimia haemolytica isolates from a Saskatchewan feedlot
(American Society for Microbiology [Society Publisher], 2024-06-12) Deschner, Darien; Voordouw, Maarten J.; Fernando, Champika; Campbell, John; Waldner, Cheryl L.; Hill, Janet E.
Mannheimia haemolytica is a major contributor to bovine respiratory disease (BRD), which causes substantial economic losses to the beef industry, and there is an urgent need for rapid and accurate diagnostic tests to provide evidence for treatment decisions and support antimicrobial stewardship. Diagnostic sequencing can provide information about antimicrobial resistance genes in M. haemolytica more rapidly than conventional diagnostics. Realizing the full potential of diagnostic sequencing requires a comprehensive understanding of the genetic markers of antimicrobial resistance. We identified genetic markers of resistance in M. haemolytica to macrolide class antibiotics commonly used for control of BRD. Genome sequences were determined for 99 M. haemolytica isolates with six different susceptibility phenotypes collected over 2 years from a feedlot in Saskatchewan, Canada. Known macrolide resistance genes estT, msr(E), and mph(E) were identified in most resistant isolates within predicted integrative and conjugative elements (ICEs). ICE sequences lacking antibiotic resistance genes were detected in 10 of 47 susceptible isolates. No resistance-associated polymorphisms were detected in ribosomal RNA genes, although previously unreported mutations in the L22 and L23 ribosomal proteins were identified in 12 and 27 resistant isolates, respectively. Pangenome analysis led to the identification of 79 genes associated with resistance to gamithromycin, of which 95% (75 of 79) had no functional annotation. Most of the observed phenotypic resistance was explained by previously identified antibiotic resistance genes, although resistance to the macrolides gamithromycin and tulathromycin was not explained in 39 of 47 isolates, demonstrating the need for continued surveillance for novel determinants of macrolide resistance.
Insight into antimicrobial resistance at a new beef cattle feedlot in western Canada
(AMS Journals, 2023-10) Kos, Daniel; Schreiner, Brittany; Thiessen, Stuart; McAllister, Tim; Jelinski, Murray; Ruzzini, Antonio
In North America, beef production relies on the administration of antimicrobials to manage disease. Bovine respiratory disease (BRD) is the most significant disease of beef cattle, and antimicrobial resistance (AMR) to conventional therapies presents an existential risk to animal welfare and food production. While AMR surveillance programs are poised to help facilitate antimicrobial stewardship and decision making at feedlots, monitoring strategies for large numbers of animals at an individual or group level are time consuming and costly. Accordingly, we completed a pilot investigation of feedlot water bowls, which is an understudied interface between cattle and bacteria. By performing cultivation-dependent and cultivation-independent studies, we demonstrate that water bowl-dwelling bacteria can act as sentinel organisms for clinically relevant antimicrobial resistance genes (ARGs) and that cattle have an impact on the microbial communities in the bowls. Moreover, by sampling water at a feedlot site before animal arrival, we detected resistance to two antibiotics: florfenicol and tulathromycin. After just 4 weeks of operation, multidrug-resistant bacteria were routinely found in most water bowls. A comparison of ARGs encoded by five water bowl bacterial isolates along with previously reported source and wastewater metagenomes to those found in BRD pathogens confirmed the utility of using water samples for AMR surveillance.
Laboratory Procedures Manual
(2024-03-01) Madalagama Appuhamilage, Roshan Priyantha; Rubin, Joseph E.
The development of this laboratory manual was a collaboration between Drs. M.A.R. Priyantha and J.E. Rubin. This manual is intended to serve as a foundational guide to the microbiological techniques and principles required for diagnostic and research microbiology. These materials were developed specifically for the regional labs within the Department of Animal Production and Health and the Veterinary Research Institute of Sri Lanka.
Laboratory Procedures Manual
(2025-03-04) Madalagama Appuhamilage, Roshan Priyantha; Rubin, Joseph
The development of this laboratory manual was a collaboration between Drs. M.A.R. Priyantha and J.E. Rubin. This manual is intended to serve as a starting point bacterial identification using biochemical tests. These materials were developed specifically for the regional labs within the Department of Animal Production and Health and the Veterinary Research Instituteof Sri Lanka.
New approaches to teaching the art and science of veterinary medicine
(AVMA Publications, 2022-12-01) Muir, Gillian; MacDonald, Myrna
Outcomes of surgically treated sialoceles in 21 cats: A multi-institutional retrospective study (2010–2021)
(Wiley, 2024-07-31) Marti, Laura G.; Del Carpio, Laura-Isabela; Goldschmidt, Stephanie; Gagnon, Dominique; Shmon, Cindy; Sterman, Allyson A.; Scharf, Valery F.; MacPhail, Catriona M.; Maki, Lynn; Arzi, Boaz
Abstract Objective: To report the outcomes of cats that underwent surgical correction for sialoceles. Study design: Multi-institutional retrospective cohort study. Animals: Twenty-one client-owned cats. Methods: Medical records were examined of cats diagnosed with sialocele, which underwent surgical intervention over an 11-year period at one of10 referral hospitals. The data collected included signalment, clinical signs, diagnostic imaging, histopathology, surgical procedures performed, and post-operative complications. Results: The most common presenting complaints for cats with sialocele included dysphagia and ptyalism. Only two cats had a recent history of trauma, and one was diagnosed with a concurrent sialolith. Most displayed visible tis-sue swelling, with ranulae being most common. Surgical treatment consisted of sialoadenectomy and/or marsupialization. Intraoperative complications occurred in three cats, and postoperative complications in five cats. No recurrence or development of contralateral sialoceles were reported during the follow-up period (30–968 days). Conclusion: The majority of cats did not have a clear underlying cause for developing a sialocele. The sublingual and mandibular salivary glands were presumed to be the most commonly affected. Mandibular and sublingual sialoadenectomy and/or marsupialization provided resolution of clinical signs to the 21 cats that underwent these procedures. Clinical significance: Sialocele, although rare, should remain a differential diagnosis when managing cats with relevant clinical signs. Surgical intervention appears to offer resolution of signs with apparently low over-all risk of complication or short-term recurrence. In cats it is necessary to evaluate whether sialoadenectomy is necessary, or whether marsupialization alone should be attempted as a less invasive first-line surgical intervention.
Participant Consent Form
(2023) Monique, Mayer

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