Kirk A Muñoz¹, Alexa Acevedo¹, Molly Stec¹, Kathryn Pitt², Sarah Jones³, Jane M Manfredi¹ 1) College of Veterinary Medicine, 2) Locum surgeon, 3) MedVet

Post-operative nausea is an undesirable complication after a laparoscopic procedure; ondansetron might ameliorate this effect. Twenty client-owned healthy male dogs were enrolled in this prospective clinical trial. Dogs were premedicated with dexmedetomidine (2-5 mcg/kg) and methadone (0.2-0.5 mg/kg) intramuscularly, induced with propofol, and maintained under general anesthesia with inhalant anesthetic. Dogs were randomized into two groups, ondansetron (ondansetron 0.2 mg/kg, intravenously) and saline (saline 0.1 mL/kg, intravenously) groups. Plasma and serum were collected before premedication and three hours after extubation to measure arginine vasopressin (AVP) and cortisol concentrations. Nausea scoring occurred 10 minutes after premedication, immediately after extubation, and at one, two, and three hours post-extubation by blinded observers. Statistics included: repeated measures ANOVAs and Mann-Whitney U tests (significant at p < 0.05). Cortisol concentrations were higher post-operatively versus pre-operatively ( p < 0.0001) in both groups. There was no significant difference between groups or between groups over time for cortisol ( p = 0.237; 0.16) and AVP concentrations ( p = 0.96; 0.92) or nausea scores (p = 0.739; 0.973), respectively. The dosage of propofol administered at induction ( p = 0.38), intraoperatively (p = 0.82) and when administered intraoperatively (p = 0.62) were not significantly different between groups. Ondansetron did not affect the incidence of nausea, as neither group demonstrated this state. Propofol, an induction agent, which has some evidence of anti-nausea properties in humans, should be explored as a cause for the lack of post-operative nausea seen in these dogs.

Khelsea Bahr, Suelee Robbe-Austermann, Tyler Thacker, Evan Brenner, Joe Darish, Srinand Sreevatsan Michigan State University College of Veterinary Medicine, Pathobiology and diagnostic investigation department, USDANational Veterinary Services Laboratory, Ames, IA

Tuberculosis is a disease of multiple host species, caused by members of the Mycobacterium tuberculosis Complex. Tuberculosis remains as one of the leading causes of death among people (caused by Mycobacterium tuberculosis variant tuberculosis) and devastating economic losses to animal agriculture( Mycobacterium bovis or MBO). The purpose of this research project is to index genomic signatures among elk isolates of MBO and provide an understanding of their divergence from other strains infecting animals and humans. In previous work using MassArray based SNP typing it was shown that all elk isolates from different geographic locations in the US, clustered separately into a unique clade. That study was based on a priori knowledge of genomic SNPs that was biased since those unique to these isolates based on de novo analysis were likely missed. Thus, we posit that genome wide analysis for unique single nucleotide polymorphisms and/or insertion-deletion events is expected to provide strong scientific foundations to understand host adaptation, host range, and zoonotic potential. Whole genomic DNA from MBO isolates (from elk) were prepared, MBO genomic DNA from elk obtained from USDA were amplified and genomes sequenced with Illumina (NovaSeq) technology. Genomes are assembled de novo and compared against a library of MBO draft genomes available from NVSL and the PARTIC databases to identify unique changes in the lineages and define the evolutionary trajectory of elk isolates. Genome analysis of this bacterium will establish within host evolution and provide a repertoire of targets that can be used in diagnostics and/or as targets for subunit vaccine development.

Brooke L Boger¹, Sarah A Shull², Amanda J Norman¹, Bea R Biddinger³, Jane M Manfredi¹ 1. Department of Pathology and Diagnostic Investigation 2. Small Animal Clinical Sciences 3. Clinical Skills Laboratory and Student Surgery, Michigan State University, College of Veterinary Medicine

Goniometry is a skill used in veterinary rehabilitation settings to help diagnose and monitor orthopedic conditions. Our objectives were to create a normal canine stifle goniometry model and to compare students’ confidence and accuracy in performing goniometry with exposure to either the model or traditional teaching methods. We hypothesized that students would demonstrate goniometry skills more confidently and accurately after using a simulation model than those given traditional materials. A flexible 3D printed model of a canine stifle was made. Twenty-eight veterinary students prepared with either instructional material from a textbook (n=13) or using the stifle model (n=15). Immediately after their accuracy in performing goniometry was assessed on a live dog. Students completed pre- and post-surveys where they indicated their confidence and anxieties. Statistical analyses included thematic analysis, descriptive statistics, and Chi Square analyses (significant at P ≤ 0.05). There was no difference in goniometry assessment or anatomy palpation scores between the model and reading groups. Clinical students (n =8) achieved higher scores in goniometry assessment (p= 0.01) and anatomy palpation (p=0.04). Students were more confident when identifying their anatomical landmarks after using prep materials as compared to before using the prep materials (P = 0.03), but only averaged identification of 3/5 landmarks. While the model does not appear to increase student confidence or accuracy, in the future if supplemented with goniometer instructions and taking in account student preferences, it may be a useful teaching aid.

Nicole Davis, Cassie Van Hoof, Harry Cridge Affiliations: Department of Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, Michigan

Discospondylitis is an infection of the intervertebral discs, adjacent cartilaginous endplates, and/or vertebral bodies. A paucity of information exists regarding canine discospondylitis which negatively impacts clinical management. The aims of our study were to describe signalment, clinical findings, treatment, and outcome in dogs with discospondylitis. Study methods included retrospective case review (01.01.10 – 12.31.21) at 4 referral institutions. A total of 172 dogs were identified. The median age of dogs was 6 years (range, 11 weeks – 15 years) and male dogs were overrepresented. Of the cases where duration of signs were known (n=136), 92 (68.1%) were chronic in duration. Twenty-three patients (17%) presented with subacute disease and 20 (14.8%) presented acutely. The most common clinical signs were lethargy, pain, and decreased appetite. Positive bacterial cultures were noted in 46 dogs (26.7%) and fungal cultures in 4 dogs (0.23%). The most common affected site was L7-S1. Twenty-one patients had evidence of discospondylitis on advanced imaging but no evidence of disease on initial radiographs. Treatment was medical in 159 dogs and surgical in 18 dogs. Of the patients with follow-up data available (n=58) 51 patients showed signs of clinical improvement while 3 patients had progressive disease, 3 patients initially improved but relapsed, and 1 patient never improved despite radiographic resolution of disease. Patients clinically improved at a median of 20 days from diagnosis (range 1-545 days). Twenty-six patients exhibited radiographic resolution of discospondylitis at a median of 110.5 days post treatment (range 20-604 days). Median duration of antibiotic use was 20 weeks.

Laura R. Hartung¹ and Kirk A. Muñoz¹ 1) College of Veterinary Medicine

This study sought to determine owners’ perception and their actions on management of pain in their pets after an ovariohysterectomy and castration procedure. An anonymous online survey was sent to about 5,200 pet owners. Responses from owners of felines and canines that were spayed or castrated within the last six months were included. Thirty-five questions including demographic information, if they have a painful health condition and how they manage it, level of importance of adequate pain management of their pets, how well their pet’s pain was controlled, if they administered the prescribed pain medications to their pets, and if intervention was taken to alleviate any signs of pain in their pets. Thematic analysis, Fisher’s exact test, and χ2 analyses, were performed (p < 0.05). One hundred and ninety-two owners met the inclusion criteria. Owners ranked the importance of pain management for their pets after ovariohysterectomy or castration at 8.87 on a 10- point scale, and the adequacy of pain control in their pets at 8.72 on a 10-point scale. 24% of owners thought that their pets were painful after surgery. There was no significant association between if the pet was perceived to be painful, and age of owner (p = 0.569), gender of owner (p = 0.888), and if owner had a painful condition (p = 0.16). Felines were discharged with pain medications after surgery in 6.7% of cases, and canines 17.4% of cases. Owners perceived that their pets’ pain management was adequate after ovariohysterectomy and castration. Owner gender, education level, and diagnosis of a painful health condition did not influence perception of pain in their pets, or compliance with administering pain medications as directed by their veterinarian (p > 0.05).

Kaitlyn G. Nikirk, College of Veterinary Medicine, Michigan State University; Jack Kottwitz PhD, DVM Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University

Veterinarians may be over or under estimating pet owners’ reliance on the internet for medical, husbandry, and general care information for pets, especially non-domestic pets like birds. While training in exotic medicine is not a staple for veterinary school curriculums, according to the AVMA, more than 13 percent of U.S. households owned an exotic or specialty pet at year-end 2016, which is a 25 percent increase from 2011. With birds being the 4th most popular pet in the US, many bird owners are left with the question of how to provide medical care for their pet, with some turning to Facebook groups for peer advice. The purpose of this study is to gain initial insight into factors that may contribute to why clients ask for medical advice on social media. Factors explored included: demographics, what minor and major clinical signs owners ask about on social media and take their bird to the vet, assessment of owner’s trust in the veterinarian, the effect of distance to an avian veterinarian, veterinarian response time to owner questions, cost of the veterinary visit, and owner’s belief in their ability to fix a bird without involving an expert. Data was obtained via Qualtrics, an online survey platform. Permission from Facebook group moderators was obtained, and the survey posted. Voluntary Facebook user responses were recorded for 30 days. Descriptive statistical analysis was performed based on answers provided.

Amanda Norman, Elaine Norton, Dalen Agnew, Chelsey Yob, and Jane Manfredi Pathobiology and Diagnostic Investigation (Norman, Agnew, Yob, Manfredi) Michigan State University College of Veterinary Medicine, East Lansing, MI; Animal and Comparative Biomedical Sciences (Norton), The University of Arizona College of Agricultural and Life Sciences, Tucson, AZ.

Gestational diabetes mellitus (GDM) in humans can lead to significant histological and secondary functional placental changes which can lead to fetal hypoxia and growth abnormalities. It is unknown if this occurs in horses. We hypothesize that the equine placenta from horses with insulin dysregulation (ID; similar to GDM) will show increased weight, immature villi, choriangiosis and ischemic lesions as compared to insulin sensitive (IS) horses. Placentas were collected immediately after expulsion from ten adult Arabian mares. The weight and gross characteristics of the placenta were recorded, along with mare reproductive history. Histological samples were collected from various areas of the placenta using a Swiss roll method and H & E slides which were randomized, read blindly and lesions were scored as not present, mild, moderate, or severe. Endocrine testing (baseline ACTH and Oral Sugar Tests) was performed on all mares. Comparisons were made between ID and IS mares using Student’s t-tests and Spearman’s Correlation Coefficients (significant at p < 0.05). There were six IS mares and four ID mares. Mares with ID have more histologic lesions (immature villi, thickened basement membrane, chorangiosis, fibrinoid degeneration, edema, and hemorrhage; all p values <0.05) and heavier placental weights (p=0.04) than IS mares. There were no significant correlations between histologic score and age, parity, or BCS. Findings from this study could support an equine translational model of placental dysfunction as well as guide peri-natal mare and foal care.

Jessica M. Rogers,¹ Jack J. Kottwitz,^1,2,3 and Amelia S. Munsterman,^1,2 1) College of Veterinary Medicine, 2) Large Animal Clinical Sciences, 3) Pharmacology and Toxicology, Michigan State University

Gastrointestinal disease resulting in abdominal pain, or colic, is a common cause of morbidity and mortality in horses. Hand-walking has been recommended by equine veterinarians anecdotally to both increase gastrointestinal motility and prevent horses from self-harm. However, the effect of hand-walking on gastrointestinal motility has not been directly measured. Electrointestinography (EIG) is a noninvasive technique used to evaluate changes in gastrointestinal motility by capturing slow wave electrical activity produced by the cells of Cajal. This study hypothesized that hand-walking would increase gastrointestinal motility in healthy, adult horses, measured by EIG, transabdominal ultrasound, and auscultation. After a 16 hour fast, a 30-minute EIG, along with transabdominal ultrasound and auscultation of borborygmi, were performed to measure baseline activity. The horses were then hand-walked, or stall rested for 15 minutes. Gastrointestinal motility measurements (EIG, ultrasound, and auscultation) were repeated immediately post-treatment and at 2 hours in a crossover design. Comparisons of EIG slow wave dominant power ratios and the dominant frequency were performed, as well as the number of contractions measured with ultrasound and auscultation. There was no difference observed in dominant power (P>0.58), dominant frequency (P>0.11) and number of contractions noted by ultrasound and auscultation (P>0.05) in horses that were hand-walked versus horses that were rested. The results of study do not support the use of hand-walking as a method to improve gastrointestinal motility. Evaluation is needed in horses with colic to confirm these findings.

Nicole Davis, Cassie Van Hoof, Harry Cridge. Affiliations: Department of Small Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, Michigan.

Discospondylitis is an infection of the intervertebral discs, adjacent cartilaginous endplates, and/or vertebral bodies. A paucity of information exists regarding canine discospondylitis which negatively impacts clinical management. The aims of our study were to describe signalment, clinical findings, treatment, and outcome in dogs with discospondylitis. Study methods included retrospective case review (01.01.10 – 12.31.21) at 4 referral institutions. A total of 172 dogs were identified. The median age of dogs was 6 years (range, 11 weeks – 15 years) and male dogs were overrepresented. Of the cases where duration of signs were known (n=136), 92 (68.1%) were chronic in duration. Twenty-three patients (17%) presented with subacute disease and 20 (14.8%) presented acutely. The most common clinical signs were lethargy, pain, and decreased appetite. Positive bacterial cultures were noted in 46 dogs (26.7%) and fungal cultures in 4 dogs (0.23%). The most common affected site was L7-S1. Twenty-one patients had evidence of discospondylitis on advanced imaging but no evidence of disease on initial radiographs. Treatment was medical in 159 dogs and surgical in 18 dogs. Of the patients with follow-up data available (n=58) 51 patients showed signs of clinical improvement while 3 patients had progressive disease, 3 patients initially improved but relapsed, and 1 patient never improved despite radiographic resolution of disease. Patients clinically improved at a median of 20 days from diagnosis (range 1-545 days). Twenty-six patients exhibited radiographic resolution of discospondylitis at a median of 110.5 days post treatment (range 20-604 days). Median duration of antibiotic use was 20 weeks.

Glorian Berrios-Vazquez¹, Kim Giessler¹, Gisela Soboll Hussey¹ 1) Pathobiology and Diagnostics Investigation, College of Veterinary Medicine, Michigan State University

Equine herpesvirus 1(EHV-1) is a major cause of respiratory disease in horses worldwide. In addition, EHV-1 can cause abortions, and equine herpesvirus myeloencephalopathy (EHM). Evidence suggests that early events at the respiratory tract determine immediate defense, transfer of the virus to PBMCs, and incidence of secondary disease. We hypothesized that infection of equine respiratory explants with EHV-1 and EHV-1 mutants can be used to identify the role of viral genes in the modulation of respiratory immunity and establishment of viremia. Equine tracheal explants were collected from 4 respiratory healthy horses euthanized for unrelated reasons and inoculated with EHV-1 or EHV-1 mutants based on their role in host immunomodulation and viral transfer (Ab4 N752, Ab4 gB4, Ab4ΔgI-gE, Ab4ΔOrf1, Ab4ΔORF2, Ab4 gD4, and Ab4ΔUS3). Tissues were collected at 12, 24, 48, 72 and 96 hpi for the determination of viral growth curves by real-time quantitative PCR and Immunohistochemistry (IHC). Tissues were also collected at 3, 6, 12, and 24 hpi for assessing interferon responses and cytokine/chemokine mRNA expression. At 24 and 48 hpi, deletion of Orf1 increased viral replication in comparison to wildtype inoculation and inoculation with the other mutants. Replacement of gD with gD of EHV-4 showed an increase in viral replication when compared to wild-type inoculation. Total endpoint titers were comparable between mutants and wild-type virus for all mutants. Interferon, cytokine, and chemokine responses are currently being evaluated to identify gene candidates that modulate the immune response during EHV-1 infection and EHM pathogenesis. Our results highlight the value of using primary equine respiratory explants and viral mutants for the selection of viral candidate genes involved in EHM pathogenesis and immunomodulation.

Miguel Chirivi¹, Daniela Cortes¹, Annette O'Connor¹, Andres Contreras¹; Department of Large Animal Clinical Sciences, Michigan State University

The current treatment for clinical ketosis (CK) is oral propylene glycol (PG) which stimulates gluconeogenesis. However, PG does not reduce adipose tissue (AT) lipolysis dysregulation, a key driver of CK. We hypothesized that NIA and Flunixin Meglumine (FM), known lipolysis inhibitors, reduce lipolysis dysregulation and improve AT insulin sensitivity in CK cows. Multiparous Jersey cows (n=72) were selected from a commercial dairy. Inclusion criteria: hyperketonemia (BHB ≥1.2 mmol/L), lethargy, and low milk yield. Cows were randomly assigned to one of 3 treatments T1) PG: 310g oral once per d for 5 d; T2) PG+NIA: 24g oral once per d for 3 d; T3) PG+NIA+FM: 1.1 mg/kg IV once per day for 3 d. Plasma was collected at enrollment (d 0) and 3, 7, and 14 d later in CK and healthy control cows (CON n=24). Subcutaneous AT was collected at d 0 and d 7 from 6 cows/group. AT explants were treated ex-vivo with insulin (IN=1μL/L) during β-adrenergic lipolysis stimulation. Lipolysis was assessed by glycerol release. At d0, CK cows showed high BHB, NEFA, haptoglobin, serum amyloid A, LPS binding protein, and proinflammatory cytokines, but low glucose concentrations compared to CON (P<0.001). Overall, T3 cows presented the greatest decrease of BHB, NEFA, and acute phase proteins, and higher glucose concentrations at d3, 7, 14. At d 0, IN reduced lipolysis by 41±8% in AT from CON, while no response was observed in CK cows (- 2.9±4%). At D7, AT from T3 had a stronger response to IN reducing lipolysis by 36.5±8% compared to T1 (26.9±7%) and T2 (7.4±8%) P<0.05. These data suggest that including NIA and FM in CK treatment reduced lipolysis and improved CK recovery and AT insulin sensitivity

B. Alexander Fonseca Martinez ¹ and Annette O'Connor ¹, 1) College of Veterinary Medicine, Michigan State University.

The significant growth and concentration of animal feeding operations (AFOs) in recent decades has increased concerns about the potential negative health impacts on communities surrounding these facilities. Studies on this topic are mainly observational, which makes the results more susceptible to systematic bias which limits the ability to make causal inferences. A systematic review was conducted to identify relevant observational studies addressing the effect of AFOs on the health of neighbors. Exposure-outcome effect sizes were extracted and thereafter the risk of bias was assessed using a tool. Next, the effects of the confounding in the body of work were analyzed: confounding variables were identified; methodology reported by the authors for the selection and identification of confounding variables as well as the statistical methods used to control for these variables were extracted; studies using directed acyclic graphs (DAGs) to describe the underlying causal structure were assessed and confounding related bias were identified. 8 case-control, 15 cross-sectional, and 10 cohort relevant studies were identified. None of the studies identified justified the choice of a set of variables as confounders, none used DAGs, multivariate methods were the unique used to control confounding and the lack of discussion for the selection of confounding variables could lead to the presence of overadjustment, residual confusion, unnecessary adjustment, and collinearity. In conclusion, confounding can prevent drawing causal conclusions in the body of work, as the sole use of multivariate models without a thorough analysis for the selection and identification of confounding factors may not capture the full spectrum of bias and generate problems derived from the efforts to control for confounding.

Peter Daniel Fowler¹ , Samuel K. Abban² Dawn Lopez² and Jay D. Evans² Meghan Milbrath³ 1) Department of Comparative Medicine and Integrative Biology, Veterinary Medical Center, Michigan State University, East Lansing, MI, 2) Bee Research Laboratory, USDA–Agricultural Research Service, East Beltsville, MD 3) Department of Entomology, Michigan State University, Lansing, MI 48910

One of the most serious bacterial pathogens of honey bees is Melissococcus plutonius, the cause of the disease European foulbrood. Because European foulbrood is highly variable, with diverse outcomes at both the individual and colony levels, it is difficult to diagnose through visual inspection alone. Common lab diagnostic techniques include microscopic examination and molecular detection through PCR. In 2009, a lateral flow device was developed and validated for field diagnosis of European foulbrood. At the time, M. plutonius was thought to be genetically homogenous, but we have subsequently learned that this bacterium exists as multiple strains, including some strains that are classified as ‘atypical’ for which the lateral flow device is potentially less effective. These devices are increasingly used in the United States, though they have never been validated using strains from North America. It is essential to validate this device in multiple locations as different strains of M. plutonius circulate in different geographical regions. In this study, we validate the field use of the lateral flow device compared to microscopic examination and qPCR on larval samples from 78 commercial honey bee colonies in the United States with visual signs of infection. In this study, microscopic diagnosis was more sensitive than the lateral flow device (sensitivity = 97.40% and 89.47%, respectively), and we found no false positive results with the lateral flow device. We find high concurrence between the three diagnostic techniques, and all three methods are highly sensitive for diagnosing European foulbrood.

Lauren K. Heine, Tasha Scarlett, James G. Wagner, Ryan P. Lewandowski, James J. Pestka, and Jack R. Harkema Michigan State University, East Lansing, MI, USA

Lupus is an autoimmune disease that affects multiple organ systems. Inhalation exposure to crystalline silica (cSiO2) has been epidemiologically linked to disease manifestation. Previously, we have shown that dietary supplementation with the omega-3 fatty acid, docosahexaenoic acid (DHA), prevents cSiO2-triggered autoimmunity and pathology in juvenile 8-week-old lupus-prone mice. In the present study, we tested the hypothesis that dietary supplementation with DHA at a human dose equivalent of 5 g/d prevents cSiO2-triggered autoimmune disease in adult lupus-prone mice that more accurately reflect the age of cSiO2-exposed workers. Female 14-week-old NZBWF1 mice received either a purified AIN-93G control (CON) or DHA amended diets. Two weeks later, mice were intranasally instilled with either saline vehicle (VEH) or 1 mg cSiO2 once per week for 4 consecutive weeks and sacrificed at 1 or 5 weeks after the last instillation (PI). Lung and kidney tissues were processed for light microscopy, immunohistochemistry, and morphometric analysis. Bronchoalveolar lavage fluid (BALF) was collected for total and differential inflammatory cell counts. VEH/CON mice had no pulmonary or renal pathology at 1- or 5-weeks PI. cSiO2/CON mice had mild pulmonary ectopic lymphoid tissue (ELT) formation at 1-week PI, with a marked increase at 5- weeks PI. Correspondingly, lungs of cSiO2/CON mice had increases in CD3+ T-cell, CD45R+ B-cell, and IgG+ plasma cell densities at both timepoints compared to VEH/CON mice. cSiO2 significantly increased macrophages and neutrophils in the BALF. Kidneys from cSiO2/CON mice had conspicuous glomerular IgG deposition. Dietary DHA dramatically attenuated cSiO2-triggered pulmonary ELT formation, increases in T-cell, B-cell and plasma cell densities, and inflammatory cell counts in BALF at both 1- and 5-weeks PI. cSiO2/DHA mice also had no IgG deposition in renal glomeruli. These results demonstrate that dietary DHA markedly prevents cSiO2-triggered lupus pathology in adult mice similar to juvenile mice of the same sex and strain.

Nathan Kauffman¹ and Kurt Zinn² 1) CMIB, Human Medicine 2) BME, Radiology, Small Animal Clinical Science, Michigan State University

Locoregional internal radioisotope therapy is an alternative treatment strategy for solid tumors when external beam radiation is contraindicated. Current therapies rely on beta- decay to deliver the radiation dose to tumors; however, radioisotopes emitting alpha particles deliver 1000x more radiation dose comparatively. Novel vehicles to deliver alpha particles are highly sought. Macroaggregated albumin (MAA) is one FDA-approved vehicle that is used widely for human clinical imaging studies and is a viable delivery platform for alpha emitters. A preformulated kit of MAA was radiolabeled with lead-214 (Pb-214, 27-min halflife, single alpha particle emission during decay) and evaluated for stability. Purified Pb-214-MAA was placed in a serum solution, incubated at 37C, and periodically sampled to measure purity and stability of the complex. Pb-214-MAA was stable for over two hours in 37C serum, with over 95% of the radioactivity remained bound to MAA. Ion chamber and phosphor imaging indicated that over 90% of the radiation dose from the Pb-214 would be from alpha particle emissions. Another MAA kit was radiolabeled with technetium-99m (Tc-99m, 6-hr halflife, gamma emissions only for imaging/biodistribution) and injected directly into mice bearing orthotopic 4T1 breast tumors (n=3) to assess Tc-99m-MAA tissue distribution. Two hours after injection, a mean of 200% of the injected dose per gram (SE=8%) was in the tumors. In summary, the MAA was lodged within the tumors and the radiopharmaceutical complex was stable. These data are supportive of using Pb-214-MAA for therapeutic studies. Current studies are ongoing for both in vitro breast cancer cell survival and in vivo Pb-214-MAA treatment in breast cancer mouse models. Future directions include combining Pb-214-MAA therapy with immune checkpoint inhibitors.

Vishvapali Kobbekaduwa¹, William Miller² and Jean Tsao³ 1) Comparative Medicine and Integrative Biology, 2) Department of Biology, Calvin College, 3) Department of Fisheries and Wildlife and Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University

In the eastern USA, blacklegged tick is the vector of Lyme disease. In Michigan, blacklegged ticks were first discovered in the late 1980s. This study aimed to develop habitat suitability models using maximum entropy (MaxEnt) to predict suitable habitats for the blacklegged ticks in Michigan. Ticks were drag sampled throughout Michigan from 2017 – 2021. According to the CDC, a site is classified as having an established tick population if at least six ticks of one life stage or two ticks of two different life stages are detected within a calendar year. A site is classified as “reported” if at least one blacklegged tick is found. Based on CDC criteria, we compared outputs for three models where tick presence comprised 1) all sites with at least one detected blacklegged tick from any year (least strict, n=171); 2) all sites with established populations based on at least one of the establishment criteria (intermediate model, n=117); or 3) all sites where both establishment criteria were attained (most strict, n=87). A random 50% of the positive sites were used to train each model, and then the remaining sites were used to test the model. The area under the curve (AUC) values were 0.938, 0.946, and 0.968 for the least, intermediate, and strict models. Five critical environmental variables were identified for developing the model: the amount of leaf litter, tree canopy cover, land cover features, average snow density, and growing degree days. According to the models, the most suitable habitats were found along coastal and southern Michigan. The lower probability occurrence sites were found in the Lower Peninsula's northern areas and the Upper Peninsula's eastern areas. Predicting the spatial distribution of disease risk is essential for targeting public health prevention messages and diagnosing and treating disease.

Janelle V. LeMon, Nidia C. Maradiaga, Yu Ping Tang, Kyan Thelen, Jeff Gandy, Andres G. Contreres, and Adam J. Moeser College of Veterinary Medicine, Michigan State University

Early life adversity (ELA) induces chronic low-grade inflammation and increases the risk for immune and metabolic dysfunction in adulthood. While the link between ELA and chronic inflammatory disease risk is well known, the mechanisms remain poorly understood. Using a model of ELA (neonatal maternal separation + early weaning; NMS), we previously demonstrated that NMS developmentally programs bone marrow derived MCs (BMMCs) to exhibit an enhanced capacity to store, release, and de novo synthesize secretory granule (SG) proinflammatory mediators. To explore the potential transcriptional mechanisms driving the NMS-induced MC phenotype, we conducted RNA sequencing and gene pathway analysis on BMMCs from adult normally handled (NH) and NMS mice, which revealed enrichment of expressed genes associated with lipid metabolism. Based on these findings, we tested the hypothesis that NMS programs MC progenitors with enhanced lipid storage and lipogenesis which is linked to enhanced SG biogenesis and inflammatory potential. Using AdipoRed to quantify triglyceride (TG) content, NMS female BMMCs had greater basal TG storage (p=.041) and following 48h culture in lipogenic media (0.1ng/mL insulin + 0.25μmol dexamethasone), compared with NH female BMMCs (p=.078). Additionally, NMS female BMMCs exhibited heightened IgE-mediated oxylipid biosynthesis and eicosanoid release, while this response was suppressed in NMS male BMMCs. Female BM progenitors cultured in the presence of the cholesterol-modifier DEUP had decreased TG levels and reduced histamine content, thus establishing a novel developmental link between lipid metabolism and MC SG biogenesis. Further studies investigating the functional role of this link are expected to provide mechanistic understanding of the long-term effects of ELA on inflammatory disease risk and reveal novel therapeutic targets.

Garrick M. Moll¹, Vilma Yuzbasiyan-Gurkan¹, Cheryl L. Swenson²; ¹Comparative Medicine & Integrative Biology, ²Pathobiology & Diagnostic Investigation, College of Veterinary Medicine, Michigan State University

Feline leukemia virus (FeLV) is a cosmopolitan gammaretrovirus that causes lifelong infections and fatal diseases including leukemias, lymphomas, immunodeficiencies, and anemias in domestic and wild felids. There is currently no definitive treatment for FeLV and while existing vaccines reduce the prevalence of progressive infections, they neither provide sterilizing immunity nor prevent regressive infections that result in viral reservoirs with potential for reactivation, transmission, and development of associated clinical diseases. Previous studies of murine leukemia virus (MuLV) established that host cell epigenetic reader Bromodomain & Extra-Terminal domain (BET) proteins exert a dual faciliatory effect on MuLV replication: molecular tethering of integrase to N-ε-acetyl-L-lysine chromatin residues via their bromodomains and allosteric activation of integrase enzymatic activity via their extra-terminal domain, thereby promoting proviral integration. Here, we show that this faciliatory effect of BET proteins extends to FeLV. Infection and treatment of two phenotypically disparate feline cell lines, 81C fibroblasts and 3201 lymphoma cells, with BET protein bromodomain inhibitor (+)-JQ1 significantly inhibits proviral integration; total FeLV DNA load, FeLV proviral load, and subsequently FeLV p27 capsid protein expression, were significantly attenuated in a dose-dependent manner. These findings elucidate the importance of BET proteins for efficient FeLV integration and provide a prudent direction for development of treatments for FeLV infections.

Madison Myers¹, Ursula Abou-Rjeileh¹, Miguel Chirivi¹, Jair Parales², Adam Lock², Joseph Tam³, Maya Zachut⁴, Andres Contreras¹ 1) Large Animal Clinical Sci., CVM, MSU, 2) Animal Sci., CANR, MSU, 3) Obesity and Met. Lab., Hebrew U., Ruminant Sci., Volcani Center

In periparturient (PP) dairy cows, lipid mobilization from adipose tissue (AT) compensates for disparities between energy expenditure and nutrient intake. Lipolytic intensity subsides as lactation progresses, however, if excessive and/or protracted, disease risk is amplified. Reducing AT lipid release and enhancing storage capacity may improve cows’ health and productivity. Cannabinoid 1 receptor (CB1R) activation enhances AT energy conservation in rodent AT, however, effects in cows are unknown. We determined CB1R activation’s effects on bovine AT lipolysis, adipogenesis, and lipolysis using a CB1R agonist (arachidonyl-2'-chloroethylamide; ACEA) and an antagonist (Rimonabant; RIM). AT was collected from healthy, non-lactating, non-gestating (NLNG) and PP cows at -7, +14, and +21d relative to calving. Lipolysis, quantified by glycerol release, was stimulated in AT explants with/without ACEA±RIM. CB1R activation reduced lipolysis in in NLNG cow AT. Lipolysis in all PP samples was unaffected by ACEA±RIM exposure. To determine CB1R’s adipogenic and lipogenic effects (quantified based on lipid accumulation and expression of key genes/proteins), preadipocytes were isolated from NLNG cows’ AT, cultured, and differentiated for 4 or 12d with/without ACEA±RIM. Adipogenesis was promoted by ACEA and reduced by RIM. Lipogenesis was enhanced in AT exposed to ACEA or RIM, but not ACEA+RIM. In summary, CB1R activation promotes AT adipogenesis and lipogenesis and, in NLNG cows, reduces lipolysis. Stimulating AT CB1R may enhance energy conservation and improve the health and production of dairy cows.

Rendon CJ¹, Flood ED², Watts SW², Contreras GA¹. 1.Large Animal Clinical Sciences and 2.Pharmacology and Toxicology, Michigan State University.

Perivascular adipose tissue (PVAT) modifies vascular function due to its capacity to synthesize vasoactive products and its mechanical properties. During cardiovascular diseases (CVD), changes in adipose tissue (AT) affect PVAT function. In hypertension, expansion of AT associated to obesity exhibit sex-related differences in a site-dependent manner. However, how adipocyte progenitors (APC) contribute to those differences in PVAT depots is currently unknown. Our objective was to evaluate APC distribution among different AT sites in both sexes under healthy conditions. We hypothesize that APC population distribution differs by age, sex, and anatomical depot. PVAT from abdominal and thoracic aorta, mesenteric arteries, and non-PVAT subscapular (BAT), perigonadal (GON), and subcutaneous (SCAT) were collected from 13 and 30-week-old female and male double transgenic mice (PDGFRa-CreERT2/R26-LSL-tdTomato; n=17). Tamoxifen (5d, 150 mg/kg) induced the expression of tdTomato reporter in the well defined PDGFRa+ APC populations. AT was digested [Liberase™]and then after filtration the cell suspension was incubated with antibodies anti CD45, CD31, and Zombie NIR. Flow cytometry was performed to quantify APC population defined as CD45-, CD31-, and tdTomato+; results are reported as % APC±SEM. Among PVAT sites, abPVAT had fewer APC (1.17±0.25) compared with GON (5.6±0.25). Age reduced APC population aortic PVAT. There were no sex differences in APC populations in PVAT; however, in GON, males (1.28±0.75; n=4) had fewer APC compared to females (9.92±0.31; n=9). These results might explain the different expansion potential of AT depots, regarding sex, also the effect of aging could reduce the adipogenic potential of PVATs; in future experiments, we will study how APC can be affected by hypertensive conditions.

Hinako Terauchi^1,2, Julia A. Bell¹, Yu Jiang⁴, Hongmei Zhang⁴, John W. Holloway⁵, Susan L. Ewart³, Hasan Arshad^5,6, Linda S. Mansfield^{1, 2, 3} 1Comparative Enteric Diseases Laboratory, 2Microbiology and Molecular Genetics, 3College of Veterinary Medicine, Michigan State University, 4University of Memphis, 5University of Southampton, 6The David Hide Asthma and Allergy Research Centre, UK

Incidence of atopic and autoimmune disorders have been on the rise in industrialized nations. The exact cause and mechanism for this rise in incidence have yet to be clearly determined. Many factors have been associated with this rise in such disorders including genetics, epigenetics, environmental toxins and particulates, as well as the microbiota. The host microbiome has been associated with a multitude of human and animal diseases, disorders, and conditions, and its involvement in the atopic and autoimmune disorders is an ever-growing field of new knowledge. One leading hypothesis is that the start-of-life microbiota determines such outcomes, as it is responsible for early-life immune system development. To further investigate this hypothesis, we analyzed fecal microbiota data from fecal samples of 3-month-old infants enrolled in the Isle of Wight Allergy Cohort study. These infants were followed clinically longitudinally, providing their atopic and autoimmune disorder status. We focused on eczema, or atopic dermatitis, which can be diagnosed in infancy, and associated with later development of additional autoimmune disorders. An increase in the number of positive eczema diagnoses with age was observed within the first 12 months in this study group, coinciding with the national data of increase in number of eczema and related diseases with age in children. Out of the 80 bacterial clusters (OTU’s) identified by 16SV4 rRNA amplicon sequencing, the genus Veillonella was associated with eczema diagnosis at 3 months of age. Infants who had a positive diagnosis of eczema had consistently higher relative abundance of genus Veillonella whether grouped by diagnosis status at 3, 6, or 12 months. Veillonella contains both commensal and pathogenic species that resides in human oral cavities, often causing periodontal diseases. Our study suggests having an increased abundance of Veillonella spp. in early gut microbiota may pose an increased risk of developing eczema.

Kyan Thelen¹, Neco Wilson¹, Masha Fardisi¹, Carmen-Maria Garcia¹, Adam J. Moeser¹ Large Animal Clinical Sciences Department, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan

Weaning associated intestinal inflammation is detrimental for short and long-term health, but the mechanism by which inflammation is triggered is unclear and thus early targeted anti-inflammatory interventions are lacking. Previous studies investigating the impact of weaning stress in piglets showed that histamine is released shortly after weaning and is followed by increased gene expression of histamine receptor 2 (H2R) in intestinal mucosa. The precise contribution of histamine and histamine receptor subtypes to weaning stress-induced intestinal inflammation is unknown. Here we tested the hypothesis that weaning induced intestinal inflammation is mediated by H2R. Fifteen-day-old Yorkshire piglets were administered either saline vehicle, H1R antagonist desloratadine (2 mg/kg) or H2R antagonist, famotidine (4 mg/kg), 30 minutes prior to weaning. At weaning, piglets were weaned from their dams and housed in nursery pens with ad libitum access to water. At 8 and 24 hours post-weaning, mid-jejunum was collected for IHC localization of H1R and H2R as well as qPCR gene and protein expression to assess markers of immune activation and. IHC analysis revealed increased expression of H1R in the intestinal lamina propria and of H2R in epithelium at 8 hours post weaning. Compared with saline-treated controls, piglets administered either desloratadine or famotidine had increased gene expression of jejunal adhesion molecules, while only animals administered famotidine had reduced protein expression of jejunal MPO and IL1-β. Together, these data demonstrate that histamine via H2R plays an important role in early weaning stress-induced intestinal inflammation and provides a potential target for mediation of the stress response to weaning practices.

Zimu (Christine) Wei¹, Kevin Baker¹, Dafna Groeneveld¹, Lauren Poole¹, Holly Cline-Fedewa¹, Matthew Flick², James Luyendyk^{1 1}MSU. ²UNC.

Acetaminophen (APAP) hepatotoxicity is associated with rapid activation of the coagulation protease thrombin and hepatic accumulation of its primary substrate fibrinogen. Inhibition of thrombin-mediated fibrin clot formation enhanced peak APAP hepatotoxicity in mice. Surprisingly, the magnitude and timing of traditional fibrin formation in the APAP-injured liver are not fully understood. In fact, recent studies suggest at peak liver injury, the majority of fibrin(ogen) in the APAP-injured liver accumulates through a unique thrombin-independent mechanism. We tested the hypothesis that traditional thrombin-mediated fibrin clot formation occurs early after APAP challenge in mice. FibrinogenAEK (FibAEK) mice, which express mutant fibrinogen that cannot support thrombin-mediated fibrin formation, and wild-type mice were challenged with a hepatotoxic dose of APAP (300 mg/kg) and liver and plasma samples collected 6 hours later. APAP-induced hepatic injury was similar in wild-type and FibAEK mice, indicated by serum alanine aminotransferase activity and area of hepatic necrosis. Immunohistochemistry revealed similar fibrin(ogen) accumulation within areas of necrosis in both wild-type and FibAEK mice challenged with APAP. Western blotting revealed robust fibrinogen accumulation in the insoluble protein fraction in livers of APAP-challenged wild-type mice. In contrast, fibrinogen in livers of APAP-challenged FibAEK mice did not partition to the insoluble fraction and was instead retained in the soluble protein fraction. The results indicate the rapid formation of insoluble fibrin in the APAP-injured liver does not contribute to APAP hepatotoxicity. Alongside prior studies, the results imply early thrombin-mediated fibrin polymer formation precedes and pairs with thrombinindependent pathways to drive fibrinogen accumulation in the injured liver.

Duque-Wilckens, N.^1,2; Joseph, D¹.; Maradiaga, N.²; Szu-ying, Y.³; Nestler, E.³; Subramanian, H.¹; Robison, A.J.¹; Moeser, A.J.² 1)Dept. of Physiology, Michigan State University. 2)Dept. of Large Animal Clinical Sciences, Michigan State University. 3.Icahn School of Medicine at Mount Sinai.

Mast cells (MCs) are innate immune cells with multiple physiologic functions thanks to their capacity to respond to a variety of stimuli and release bioactive molecules ranging from cytokines to neurotransmitters. Surprisingly, the transcriptional mechanisms controlling MC responses remain unknown. Based on findings that stress and IGE-mediated activation of MCs increase the expression of FosB, we hypothesized that FosB plays a fundamental role in regulating stimulus-induced MC activation and mediator release. To test this, we crossed the Mcpt5-Cre with the Cre-dependent floxed FosB mouse lines to ablate FosB expression specifically in MCs (MC^FosB-). In vitro studies showed that bone marrow derived mast cells (BMMCs) from MC ^FosB- show increased IGE-antigen induced Ca ²⁺ mobilization and release of proinflammatory mediators compared to wild type (WT) BMMCs. We next combined CUT&RUN and RNAseq data from baseline and activated BMMCs and found that one of ΔFosB functional targets is the dual specificity phosphatase Dusp4, critical negative regulator of IGE-mediated activation of mitogen-activated protein kinases (MAPKs). Finally, in vivo experiments showed that MC^FosB mice show exaggerated hypothermic responses, plasma inflammatory cytokines, and activation of mesenteric MCs after passive systemic anaphylaxis. Together, these data show that FosB products exert an inhibitory effect on MC activation and proinflammatory mediator release in vitro and in vivo and suggest that this effect could be partly mediated by DUSP1 mediated dephosphorylation of MAPKs.

Cahya Kurnia Fusianto¹, Luke VanBlois¹, Juan-Ting Liu¹, Gary Whelan², Bartolomeo Gorgoglione¹ 1) Dept. Pathobiology and Diagnostic Investigation & Dept. Fisheries and Wildlife, Michigan State University 2) Fisheries Division, Michigan Department of Natural Resources, MI

Changing ecosystems expose fishes to emerging pathogens, threatening wild and enhanced populations. The myxozoan parasite Tetracapsuloides bryosalmonae causes Proliferative Kidney Disease (PKD), a severe immunosuppressant pathology that impacts salmonid management. In North America, T. bryosalmonae infections are known in Trout and Pacific Salmon species across Western States, up to Alaska, but have never been reported in the Great Lakes. We opportunistically sampled Chinook (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch) at river weirs during their seasonal spawning migrations. During the Fall of 2020 and 2021, 167 kidney samples were collected from adults (sexually mature) and jacks (precocious males), returning from Lake Michigan (at Boardman River, Little Manistee River, and Platte River weirs), and from Lake Huron (Swan River weir). PCR assessment targeted the T. bryosalmonae 18S rRNA. Both adults and jacks of Chinook and Coho Salmon were found positive to T. bryosalmonae. Parasite prevalence varied across sites and species (7 to 52%). BLAST analysis unequivocally confirmed the first detection of T. bryosalmonae from fish hosts in the Great Lakes. Further studies are ongoing to better assess T. bryosalmonae presence across the Great Lakes, and to confirm any occurrence of PKD in each species. Prophylactic and therapeutic treatments against PKD are still not available, hence predicting outcomes of T. bryosalmonae infections and PKD outbreaks may guide actionable management solutions to mitigate economic and ecological damages in the larger freshwater system in the world.

Juan-Ting Liu¹, Jie Li², Vikram N. Vakharia², Bartolomeo Gorgoglione¹, 1) Fish Pathobiology and Immunology Laboratory, Dept. Pathobiology and Diagnostic Investigation & Dept. Fisheries and Wildlife, Michigan State University, 2) Institute of Marine & Environmental Technology, Dept. of Marine Biotechnology, University of Maryland

Infectious haematopoietic necrosis (IHN) is a major economic concern in aquaculture, indeed is OIE-notifiable. An injectable plasmid-based DNA vaccine of glycoprotein (G) gene is available, but there are no oral vaccines available for juvenile fish. Two recombinant baculoviruses were generated to produce IHNV-G and IHNV-G-C5a proteins in cabbage looper (Trichoplusia ni) larvae. In the latter construct, the complement C5a was coupled with IHNV-G protein to enhance the host immune response. Insects expressing target proteins were converted into a powder, and added to artificial feed at 3%, top coated with gelatin binder and oil. Rainbow trout were fed with commercial feedings added each recombinant vaccine protein for 2 weeks and boosted 4 weeks post primary immunization. Fish were then challenged with IHNV by immersion 4 weeks after. Non-vaccinated, IHNV-G and IHNV-G-C5a fed trout reached a final cumulative mortality respectively of 97.6%, 88.4% and 81.7% by the experiment termination, at 15 days post infection (dpi). Individual viral load in spleen samples collected at 7 and 14 dpi was measured by qPCR detection of IHNV nucleoprotein from cDNA, showing no significant difference across experimental groups. The transcription of selected immune response markers including Type I IFN-a, Mx-1, CD4, and IgM genes was evaluated. Further study is needed to assess how the new oral vaccines may prevent host infection, protect from IHNV pathogenesis, thus how they modulate the host immune response towards IHNV exposure.

Sarad Paudel, Srinand Sreevatsan. Authors Affiliation: Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI

Bovine tuberculosis (TB) is one of the devastating diseases in dairy industry globally. It is caused by Mycobacterium bovis. There is an urgent need for the development of rapid and early diagnostic tools for bovine TB in different animal species for its control and prevention. Our lab has recently validated three pathogen specific biomarkers during M. bovis infection in cattle., deer, and primates. To enable facile testing in the field, we aim to develop a rapid test using DNA aptamers against the two PSBs. Systematic evolution of ligands by exponential enrichment (SELEX) is applied to select the aptamers against two mycobacterial specific proteins viz. MB2515C (a LuxR family transcription regulator) and pks5. The redundant aptamer sequences against these two proteins are identified and further characterized by gel shift assay and DNase I footprint assay followed by testing of sera from naturally infected and control animals (cattle, deer, elephants, and primates). The analytical specificity and binding affinity of each aptamer candidates against these proteins will be determined. PSB-specific, aptamerbased diagnostics to identify and track M. bovis will make major inroads to the early detection and therefore control for bovine TB in animals and humans.

Nattawipa Ampaiwan¹, Jacquelyn Jacobs¹ and Marie Hopfensperger², 1) College of Agricultural & Natural Resources, 2) College of Veterinary Medicine, Michigan State University

The transition between the animal shelter and home environments may be stressful for many dogs. Stress impacts the expression of behavior, and dogs may not display their full behavioral repertoire immediately post-adoption. Anecdotally, 3 days, 3 weeks and 3 months have been described as key timepoints post-adoption; however, the length of time until consistent behavior is demonstrated has not been evaluated. The goals of this study are two-fold: 1) describe the average length of time for recently adopted dogs to display consistent behavior, and 2) identify dog, household and environmental factors that may influence behavioral stabilization in the home environment. At the time of adoption, new owners (n = 55) were recruited to participate in a 12-week survey-based study. The survey included questions from the validated Canine Behavioral Assessment and Research Questionnaire (C-BARQ), which measures 13 different behavior constructs including excitability and activity. Questions about the home environment, attachment and owner demographics were also included. The survey was distributed via email to adopters 3 days after adoption and at weeks 1, 2, 3, 4, 8 and 12 post-adoption. Response rate varied between weeks from 52 to 69%. Thirteen adopters have completed surveys through week 12, although data collection and analysis is ongoing. Preliminary data suggests that excitability scores, measured on a scale of 0-24, decreased between day 3 (10.8 + 0.98) and week 8 (9.8 + 1.13), while energy levels, measured on a scale of 0-12, increased between day 3 (4.1 + 0.55) and week 8 (5.7 + 0.68). Results of this study could help shelter staff inform adopters what they might expect from their newly adopted shelter dog and potentially reduce shelter return rates.

Emily Beson^1,2, Niesa Kettler², Rinosh Mani² 1Department of Animal Science, MSU 2 MSU Veterinary Diagnostic Laboratory, Lansing, MI

Non-typhoidal Salmonella are widely distributed in domestic and wild animals often causing fatal infection in young and immunocompromised animals. Genus Salmonella has more than 2500 serovars determined by somatic O antigen and flagellar H antigen. Serotyping Salmonella is important in epidemiological outbreak investigation and for treatment/eradication purposes. Traditional Salmonella serotyping, a slide agglutination method involving more than 250 antisera, is labor intensive and costly. In this study, we investigated the utilization of the IRBiotyper using Fourier-transformed infrared spectroscopy (FTIR) as an alternative to traditional serotyping. To begin building a database within the IR Biotyper software, 16 lab-maintained quality-control Salmonella enterica serovars were utilized. After overnight incubation on blood agar plates, bacteria were re-streaked out for purification and inoculated into Brain Heart Infusion Broth (BHI). Overnight grown culture in BHI was centrifuged, washed in Millipore water, and reconstituted in equal volume of 70% ethanol and water. The resulting bacterial solution was vortexed and 15μL was placed on designated well of a silicon plate for spectral capture. The FTIR spectra were analyzed using the IR Biotyper software, through generation of a scatterplot and dendrogram. Scatterplots can be viewed in both principal component analysis (PCA) and linear data analysis (LDA). The laboratory maintained serovars separated into unique clusters on IR Biotyper with a couple of exceptions. Serovars belonging to C2C3 O antigen group were close together and failed to separate into unique clusters. The IR Biotyper is an extremely useful instrument for strain typing and we have demonstrated that it has the potential to differentiate Salmonella serotypes utilizing only a fraction of time, cost and labor compared to traditional serotyping.

Kirk A Muñoz¹, Jiordan Washington², Laura Hartung³, Angela Hall⁴ 1) College of Veterinary Medicine, 2) Michigan State University, 3) College of Veterinary Medicine, 4) College of Social Science, Michigan State University

To determine the effective dosage of ketamine needed to induce general anesthesia (GA) in elective, and colic horses when used in combination with midazolam at 0.08 mg/kg. A retrospective cohort study was performed. Anesthetic records from 300 horses that underwent GA between 2018 and 2022 for elective, and colic surgery were reviewed. Horses aged <6 months, and those administered anything other than xylazine as a premedicant were excluded. Only horses induced with ketamine and midazolam were included in the analysis. Data analyzed included signalment, procedure, anesthetic drugs, time administered and the amount of ketamine administered for induction of GA during induction before the horse was hoisted. Parameters such as age, breed, sex, weight, pulse rate, packed cell volume and total solids were also recorded. Chi-square, Fisher's exact and Tukey's post hoc comparison tests were used. Parametric data were reported as mean ± standard deviation with significance at p <0.05. In total, 143 healthy and 84 colic horses met the inclusion criteria. There was no significant difference in the dosage of ketamine used to induce GA in elective cases (2.5 ± 0.3 mg/kg), and colic horses (2.5 ± 0.4 mg/kg) ( p = 0.42) or in the total dosage of ketamine needed to induce GA at an appropriate plane to allow for hoisting of the horses in both elective (2.8 ± 0.5 mg/kg), and colic (2.8 ± 0.6 mg/kg) cases (p = 0.57). The dosage of ketamine needed to effectively anesthetize elective, and colic horses, with midazolam at 0.08 mg/kg, after sedation with xylazine at 0.8 mg/kg was 2.8 mg/kg, which was higher than the currently reported dosage of 2.2 mg/kg.

Billie Beckwith-Cohen¹, Paige A. Winkler¹, Laurence M. Occelli¹, Kelian Sun¹, Maciej Parys², Vilma Yuzbasiyan-Gurkan², Simon M. Petersen-Jones¹, 1) CVM, Michigan State University, 2) Microbiology and Molecular Genetics, Michigan State University.

Retinal function depends on calcium signaling and subsequent glutamate release in the first retinal synapse. Calcium binding protein-4 is required to modulate the interaction of calcium with rod- and cone-voltage gated calcium channels. Mutations in CaBP4 lead to deleterious effects on vision in people. We identified a mutation in the CaBP4 start codon in dogs which results in reduced protein production and protein mistrafficking. CaBP4 mutants have synaptic loss of function which results in an absent electroretinographic B-wave, progressive retinal atrophy and visual impairment. Affected dogs exhibit synaptic immaturity in the outer plexiform layer (OPL). While molecular changes in the OPL are present early in the disease, atrophy progresses to span all retinal layers as disease advances. Gene augmentation therapy with CaBP4 cDNA not only restores vision, but also enables retinal re-organizing, synaptic maturation and retinal layer preservation. Restoration of retinal function is illustrated with the recovery of the B-wave and vision restoration is illustrated with improved visual performance. These results offer insight to the importance of calcium regulation in both upstream and downstream structural retinal plasticity and remodeling. The recovery of previously absent anatomic features in the OPL following gene therapy is unique and supports plastic capabilities in the first retinal synapse of large mammals. This first naturally occurring large animal model of mutant-CaBP4 recapitulates important components of the human disease and illustrates the potency of gene therapy in reversing blindness caused by the mutation, paving the way for a cure to the condition.

Sara N Taylor¹, Aimee C Colbath², Jane M Manfredi³, Kirk A Muñoz¹ 1)Department of Small Animal Clinical Sciences 2)Department of Large Animal Clinical Sciences 3)Department of Pathobiology and Diagnostic Investigation. College of Veterinary Medicine, Michigan State University

Horses experience a redistribution hypothermia under general anesthesia (GA) caused by potent vasodilation from the inhalant anesthetics. Distal limbs are a major source of heat loss during anesthesia. Thus, measuring core and peripheral body temperatures may be a more effective way to monitor heat loss trends. This pilot study measured core and peripheral body temperatures in horses under GA. Seven healthy client-owned horses presenting for orthopedic procedures were sedated with xylazine, and induced with ketamine and diazepam. Butorphanol and lidocaine were administered intraoperatively, as needed. Data analysis was performed on the first 80 minutes of GA. Core body temperature was measured using rectal and intranasal thermometer probes, peripheral body temperature was measured using fetlock thermographic imaging, and room temperature was measured using a digital temperature meter. Statistical analysis included repeated measures ANOVA with Bonferroni post-hoc comparison analysis, p < 0.05. Although clinically significant, no statistically significant difference was detected in rectal (RT) and intranasal (NT) temperatures overtime. Fetlock temperatures (FLT, left: FRT, right) were lower than RT and NT at all time points. Compared to time 0, FLT was increased at 40-80 minutes, and FRT was increased at 30-80 minutes. No difference was detected between FLT and FRT overtime. In conclusion, peripheral body temperature changed faster and to a greater extent than core body temperature indicating that peripheral temperature may be a more sensitive technique for monitoring heat loss trends in horses under general anesthesia

Hilary Schwafel, MS, DVM, Intern (Soft Tissue Surgery, MSU); Maureen Spinner, DVM, DACVS-SA, (Soft Tissue Surgery, MSU)

Gallbladder mucocele, a pathologic accumulation of mucus within the gallbladder and common bile duct which is a significant cause of morbidity and mortality in canine patients, is routinely treated by cholecystectomy. Despite advances in preoperative stabilization techniques and rapid skilled intervention, a high mortality rate amongst canine patients persists. Thus, the ability to prognosticate survival of a patient to aid clinical decision-making is a point of interest. Plasma lactate has been used as a prognostic parameter in veterinary medicine for other disease processes, and previous studies have suggested similar in cholecystectomy patients. This retrospective study investigated lactate (pre-operative, post-operative, and change in) as a prognostic factor for survival in dogs undergoing cholecystectomy for treatment of gallbladder mucocele obstruction, and secondarily to report the correlation between pre-operative lactate values and presence biliary tree rupture. Medical records were searched, and cholecystectomy patients with a histologically confirmed gallbladder mucocele with blood lactate pre- and post-operative values were included, with 22 patients meeting the inclusion criteria. Logistic regression and odds ratios comparing patient survival and lactate correlation was performed. Change in lactate pre- to post-op did not reliably predict survival, but increase in lactate did seem to correlate with greater chances of biliary tree rupture. Pre-operative lactate magnitude did correlate with patient survival. (Final analysis pending).The small sample size led to the study being underpowered and therefore suggestive rather than reaching statistical significance. This is a limitation of the retrospective nature of the study, and the paucity of patients meeting the inclusion criteria. With more patients, we would anticipate statistical significance to be reached.