About

Sarah Ho is the CVM Director of Student Engagement at the College of Veterinary Medicine at NC State University. Her role involves fostering student development and engagement within the college community. The page emphasizes her position in supporting students' academic and personal growth, but does not provide specific details about her research focus, background, or key contributions.

Research topics

• Medicine
• Biology
• Veterinary medicine
• Computer Science
• Genetics
• Chemistry
• Food science
• Zoology
• Ecology
• Chromatography
• Emergency medicine
• Toxicology
• Microbiology

Selected publications

• Evaluating the Effect of Acetylsalicylic Acid in Turkey Poults Experimentally Infected with Coccidia

  Avian Diseases · 2026-03-05

  articleSenior author

  Acetylsalicylic acid (ASA), originally trademarked as Aspirin, is a common nonsteroidal anti-inflammatory drug (NSAID) used in human and veterinary medicine to mitigate pain and pyrexia caused by inflammatory processes. There is limited information on the effectiveness of ASA in turkey production. The objective of this study was to investigate the effect of ASA on turkey poults with induced coccidial enteritis. Two experimental trials were conducted. In both trials, the turkeys were divided into four groups: no coccidia + no ASA; no coccidia + ASA (NA); coccidia + no ASA (CN); and coccidia + ASA (CA). In both trials, turkeys in groups CN and CA were given 100× the dose of a commercial turkey coccida vaccine. Starting 48 hr postinoculation and for 7 days, the turkeys from groups NA and CA were given ASA (50 mg/kg per day). For Trial 1, ASA was given via oral gavage twice daily, whereas in Trial 2 (T2), ASA was in the drinking water. Poult weights and cloacal temperatures were recorded daily. Blood was collected daily from two randomly selected birds from each group for biochemical analysis and to assess the serum salicylic acid and nitric oxide (NO) levels. At the end of the trials, tissues were examined histologically, and immune gene expression was evaluated. Coccidia infection was the factor that had most significant influence on the majority of measured parameters. ASA had minimal to no effect on reducing clinical signs, minimizing weight loss, or controlling body temperature. These findings may be due to the rapid elimination of the drug or because sick birds did not consume sufficient ASA. In T2, it was estimated that the CA group poults consumed 31 mg/kg of ASA or less per day. Although the drinking water concentration was calculated to match the total daily intake (50 mg/kg per day), ASA's rapid metabolism meant that continuous low-level ingestion might not have reached the therapeutic plasma threshold achieved by two to three daily bolus doses. Because ASA is rapidly metabolized, a higher total daily dose may be required when provided in drinking water to maintain effective serum concentrations compared with bolus administration. Although the serum NO and tissue gene expression analysis showed that coccidia infection predominantly induces an inflammatory response, the anti-inflammatory effect of ASA administered to birds in the NA or CA groups were nil to minimal. This study highlights the complexity of ASA's effects on turkeys.

  PublisherDOI

• Tool-based euthanasia methods for broiler chicks: Evaluating welfare outcomes of Iris and Kelly scissors

  Poultry Science · 2025-11-08

  articleOpen access

  The most common euthanasia method for poultry is manual cervical dislocation (CD), but it is challenging to consistently perform in young chicks due to their small body size. Tool-assisted CD may offer an alternative. Our objective was to evaluate the efficacy of two tool-assisted CD methods with Iris (ICD) and Kelly (KCD) scissors compared to manual CD in 1-day-old (1DOA) and 7-day-old (7DOA) broiler chicks. Chicks were randomly and equally allocated to one of three euthanasia treatments: CD (n=20 1DOA, n=20 7DOA), ICD (n=20 1DOA, n=20 7DOA), and KCD (n=20 1DOA, n=20 7DOA). All euthanasia methods effectively rendered chicks insensible, followed by respiratory and cardiac arrest on the first attempt, with cardiac cessation occurring within 52 to 253 sec. Chicks euthanized with CD achieved cardiac arrest sooner at both ages (p=0.0154), displayed less mouth gaping at both ages (p=0.0006), lost the pupillary light reflex faster at 1DOA (p=0.0177), and displayed shorter clonic convulsions (p=0.0331) and feather erection (p=0.0538) at 7DOA compared to chicks euthanized with ICD and KCD. However, CD also displayed the highest macroscopic laceration score (p<0.0001) and subcutaneous hemorrhaging (p<0.0001) than KCD and ICD, and CD was the only method to result in decapitation. The ICD method achieved a similar consistency as CD in the site of vertebral separation, with the majority of separations occurring between C1-C2 vertebrae for both methods (p=0.0046). The KCD method resulted in lower separations (C2-C3 vertebrae; p<0.0001) and a higher incidence of vertebral and crushed fractures than CD and ICD (p=0.0303). Taken together, although all methods were successful in rendering chicks insensible, the CD resulted in insensibility metrics occurring sooner, particularly at 7DOA. However, the CD method demonstrated more lacerations and greater risk for decapitation, which may be more emotionally aversive to the person performing euthanasia. The ICD method offered an alternative to achieve similar consistency in cervical dislocation and brain trauma while minimizing macroscopic lesions and fractures.

  PublisherDOI

• Exophthalmos and Buphthalmos in Broiler Breeders Associated with Marek's Disease Virus

  Avian Diseases · 2025-10-24

  articleOpen access1st authorCorresponding

  Reporte de caso- Exoftalmos y buftalmos en reproductoras de pollos de engorde asociadas al virus de la enfermedad de Marek. Este estudio investigó la ceguera acompañada de exoftalmos unilateral o bilateral en cuatro parvadas de reproductoras de pollos de engorde. El examen histopatológico reveló queratitis, edema corneal, cataratas, uveítis y pectenitis. Además, se observó degeneración retiniana y ocasionalmente cuerpos de inclusión intranucleares, compatibles con herpesvirus, en la capa ganglionar. El análisis inmunohistoquímico de las secciones oculares reveló una mezcla de células T (CD3+) y células B (Pax5). Se detectó ADN del virus de la enfermedad de Marek tipo 1 (MDV-1) en todas las muestras de nervio óptico, líquido vítreo, retina, córnea, iris y cristalino, en niveles similares o superiores a los encontrados en el bazo. Si bien la carga de ADN del virus de la enfermedad de Marek-1 fue compatible con los niveles de latencia en todas las muestras, fue mayor en las estructuras oculares con lesiones macroscópicas y microscópicas evidentes. El nivel de ADN detectado fue compatible con la latencia del virus de la enfermedad de Marek en bazos y ojos; sin embargo, no se detectó el gene pp38 del virus de Marek oncogénico. Se han reportado lesiones similares en pollos vacunados contra el herpesvirus del pavo al ser expuestos a un virus e Marek muy virulento plus (vv+). Este es el primer informe que sugiere una posible asociación con lesiones oculares inducidas por el virus de la enfermedad de Marek en pollos vacunados con CVI988 que recibieron protección adecuada contra el desarrollo de tumores inducidos por el virus de Marek.

  PublisherOA PDFDOI

• Distribution of fluralaner in plasma and liver in broiler breeder hens and roosters following the administration of fluralaner (Bravecto®) via medicated drinking water

  Poultry Science · 2025-09-26

  articleOpen access

  Bed bugs have become resistant to traditional insecticides, and the demand for effective drugs to eradicate bed bugs on poultry farms (especially table-egg layer) and breeder farms (especially broiler breeders) is growing. Fluralaner has been shown to be effective in treating bed bug infestation in poultry. However, there is no product containing fluralaner labeled for use in chickens in the United States. In the present study, we prepared medicated drinking water using fluralaner dog chews (Bravecto®) and diethylene glycol monoethyl ether (Transcutol V). The present study aimed to determine the plasma pharmacokinetic profile and residues in liver as well as any adverse effects related to drug administration. All chickens were orally treated with fluralaner via medicated drinking water including 0.2 % (V/V) Transcutol V for 6 hours. The fluralaner dosage regimen was 0.5 mg/kg/day, twice, 7 days apart. Sparse blood collection was conducted after the first dose and tissue collection was performed the day after the second dose. The fluralaner concentrations in plasma and liver were determined using Ultra Performance Liquid Chromatography with tandem Mass Spectrometry detection (UPLC/MS/MS). Fluralaner was dissolved completely in drinking water including 0.2 % (V/V) Transcutol V with 98 % recovery with some degradation of fluralaner confirmed over time. The highest fluralaner concentration (0.56 µg/mL) in plasma was observed 24 hours after removing the first dose. Fluralaner concentrations in plasma exceeded the 50-90 % lethal concentrations of bed bugs for 168 hours following the onset of the first dose. The mean fluralaner concentration detected in the liver was 1.25 µg/g at 21 hours after removing the second dose. No visual adverse effects were observed during the entirety of the study. Enlarged kidneys were observed by gross necropsy and mild multifocal, small aggregations of lymphocytes in the parenchyma and mineralization of a few tubules in kidneys were found on histopathological examination. However, it was unclear these findings were related to drug administration. This dosing method might be helpful in controlling bed bug infestations in poultry facilities.

  PublisherDOI

• Characterization of Enterococcus faecalis Isolated from Pullet Layers with Growth Depression and Amyloid Arthropathy

  Avian Diseases · 2025-03-20 · 2 citations

  articleOpen accessSenior author

  Caracterización de Enterococcus faecalis aislado de pollitas de reemplazo de postura con depresión del crecimiento y artropatía amiloide. Enterococcus faecalis es una bacteria comensal que coloniza el intestino de mamíferos y aves. Se caracteriza por ser un patógeno oportunista y se ha asociado comúnmente con mortalidad embrionaria en etapa tardía, onfalitis, depresión del crecimiento, sepsis y artropatía amiloide en la avicultura comercial. En este estudio, los aislamientos de E. faecalis recuperados de una parvada de 6200 pollitas de postura ubicadas en Canadá exhibieron un crecimiento deficiente, uniformidad deficiente y cojera esporádica que comenzó a la semana de edad y se extendió durante toda la fase de crianza. Enterococcus faecalis se aisló de articulaciones tarsometatarsianas inflamadas de pollitas cojas que contenían material de color amarillo anaranjado y de muestras ambientales de la caseta. Se identificaron dos tipos de secuencias conocidas por ser patógenas para los pollos, ST82 y ST49, entre los aislamientos de las articulaciones. Se detectaron diecisiete genes de virulencia conocidos de E. faecalis en estas cepas, incluido gelE para la producción de gelatinasa y el gene del péptido de señalización de detección de quórum fsrB necesario para la regulación de la virulencia. El análisis filogenético reveló que una cepa ST82 aislada de una muestra ambiental estaba relacionada clonalmente con el aislamiento de la articulación. Además, ambos tipos de secuencia, ST82 y ST49, tenían genes de resistencia a los antimicrobianos contra tetraciclinas, lincosamida y estreptograminas. ST49 tenía genes de resistencia adicionales a los ionóforos comunes utilizados en la producción avícola. Se realizó un ensayo de letalidad embrionaria para determinar la patogenicidad de los aislamientos. La inoculación con ST82 resultó en una supervivencia significativamente menor de los embriones en comparación con ST49. Hasta la fecha, se han notificado casos de artropatía amiloide causada por E. faecalis en países europeos, pero rara vez en explotaciones avícolas de América del Norte. Es necesario caracterizar mejor estas cepas de E. faecalis para dilucidar las vías de transmisión, descubrir reservorios ambientales e identificar genes de virulencia específicos en el desarrollo de la artropatía amiloide en la avicultura.

  PublisherOA PDFDOI

• Effect of brooding conditions on the blood chemistry and performance of turkey poults

  The Journal of Applied Poultry Research · 2024-01-21 · 3 citations

  articleOpen access1st authorCorresponding

  Hematologic parameters and the levels of certain plasma metabolites offer an objective measure, and real-time insight into the physiological status of an animal. We hypothesized that blood chemistry analysis in brooding poults varies with even minor differences of temperature and can affect poult performance. A total of 2240 1-d-old turkey hens were assigned randomly to one of 4 treatments [Control (C) = 32C and 60%RH; Cold stress (CS) = 29C and 60%RH; Heat stress (HS) = 35C and 60%RH; and Heat stress plus Humidity (HHS) = 35C and 75%RH]. In all the treatments, the temperatures were lowered 2 degrees Celsius the first week, and 1.5 degrees Celsius each week thereafter. The relative humidity was maintained constant, as much as possible, throughout the 35 d duration of the experiment. Brooding treatment affected pH, partial carbon dioxide (pCO2), potassium (K), and sodium (Na). The treatments HS and HHS had higher pH and K, and lower pCO2 and K in the blood. These changes suggest an attempt by the poults to cool down by increased water intake and panting. Furthermore, by the end of the experiment more birds in these two treatment groups had distended crops, possible to increased water intake also. The increase of ketone in the plasma, at 3 d of age, of poults from the two warmest brooding conditions (HS and HHS) suggests that these birds were consuming less feed and using more fat as its main fuel source. Furthermore, at 28 d of age significantly more poults from HS and HHS had reduced ventricular contractility of their hearts. However, no significant differences in the concentration of creatinine kinase (CK) or cardiac troponin I (cTnI) were found between treatments. In conclusion, this research revealed that blood parameters were influenced by minor temperature and humidity changes. Warmer brooding temperatures resulted in a higher incidence of pendulous crop. Overall, there were no significant differences in the estimated BW between the treatments. Further research is needed to optimize the number of samples needed and the time of sampling to optimize brooding conditions. We also need to investigate blood parameters that can reveal reduced contractility of the heart and if the reduced myocardial contractility from birds kept at a higher temperature and relative humidity predisposes them to dilated cardiomyopathy or other metabolic diseases.

  PublisherDOI

• Megaplasmid Dissemination in Multidrug-Resistant <i>Salmonella</i> Serotypes from Backyard and Commercial Broiler Production Systems in the Southeastern United States

  Foodborne Pathogens and Disease · 2024-04-18 · 7 citations

  article

  Over the past decade, there has been a rise in U.S. backyard poultry ownership, raising concern for residential area antimicrobial-resistant (AMR) Salmonella contamination. This study aims to lay the groundwork to better understand the persistence of AMR Salmonella in residential broiler production systems and make comparisons with commercial systems. Ten backyard and 10 commercial farms were sampled at three time points across bird production. Both fecal ( n = 10) and environmental (soil, n = 5, litter/compost, n = 5, feeder, and waterer swabs, n = 6) samples were collected at each visit on days 10, 31, and 52 of production for backyard farms and days 10, 24, and 38 of production for commercial farms. AMR Salmonella was characterized phenotypically by broth microdilution and genotypically by whole-genome sequencing. Overall, Salmonella was more prevalent in commercial farm samples (52.31%) over backyard farms (19.10%). Kentucky (sequence type (ST) 152) was the most common serotype found in both backyard and commercial farms. Multidrug-resistant (MDR, resistance to ≥3 or more antimicrobial classes) isolates were found in both production systems, while ciprofloxacin- and nalidixic acid-resistant and intermediate isolates were more prevalent in commercial (33%) than backyard samples (1%). Plasmids that have been associated with MDR were found in Kentucky and Infantis isolates, particularly IncFIB(K)_1_Kpn3 megaplasmid (Infantis). Our study emphasizes the need to understand the selection pressures in disseminating megaplasmids in MDR Salmonella in distinct broiler production systems.

  PublisherDOI

• Characterization of immune responses and immunopathology in turkeys experimentally infected with clostridial dermatitis-producing strains of Clostridium septicum

  Veterinary Immunology and Immunopathology · 2024-01-24 · 3 citations

  article
  PublisherDOI

• Widespread prevalence of plasmid-mediated blaCTX-M type extended-spectrum beta-lactamase Escherichia coli in backyard broiler production systems in the United States

  PLoS ONE · 2024-06-03 · 5 citations

  articleOpen accessCorresponding

  Extended-spectrum beta-lactamase (ESBL) Escherichia coli (E. coli) is an emerging pathogen of high concern given its resistance to extended-spectrum cephalosporins. Broiler chicken, which is the number one consumed meat in the United States and worldwide, can be a reservoir of ESBL E. coli. Backyard poultry ownership is on the rise in the United States, yet there is little research investigating prevalence of ESBL E. coli in this setting. This study aims to identify the prevalence and antimicrobial resistance profiles (phenotypically and genotypically) of ESBL E. coli in some backyard and commercial broiler farms in the U.S. For this study ten backyard and ten commercial farms were visited at three time-points across flock production. Fecal (n = 10), litter/compost (n = 5), soil (n = 5), and swabs of feeders and waterers (n = 6) were collected at each visit and processed for E. coli. Assessment of ESBL phenotype was determined through using disk diffusion with 3rd generation cephalosporins, cefotaxime and ceftazidime, and that with clavulanic acid. Broth microdilution and whole genome sequencing were used to investigate both phenotypic and genotypic resistance profiles, respectively. ESBL E. coli was more prevalent in backyard farms with 12.95% of samples testing positive whereas 0.77% of commercial farm samples were positive. All isolates contained a blaCTX-M gene, the dominant variant being blaCTX-M-1, and its presence was entirely due to plasmids. Our study confirms concerns of growing resistance to fourth generation cephalosporin, cefepime, as roughly half (51.4%) of all isolates were found to be susceptible dose-dependent and few were resistant. Resistance to non-beta lactams, gentamicin and ciprofloxacin, was also detected in our samples. Our study identifies prevalence of blaCTX-M type ESBL E. coli in U.S. backyard broiler farms, emphasizing the need for interventions for food and production safety.

  PublisherOA PDFDOI

• Immunization of turkeys with Clostridium septicum alpha toxin-based recombinant subunit proteins can confer protection against experimental Clostridial dermatitis

  PLoS ONE · 2024-04-29 · 5 citations

  articleOpen access

  Clostridial dermatitis (CD), caused by Clostridium septicum , is an emerging disease of increasing economic importance in turkeys. Currently, there are no effective vaccines for CD control. Here, two non-toxic domains of C . septicum alpha toxin, namely ntATX-D1 and ntATX-D2, were identified, cloned, and expressed in Escherichia coli as recombinant subunit proteins to investigate their use as potential vaccine candidates. Experimental groups consisted of a Negative control (NCx) that did not receive C . septicum challenge, while the adjuvant-only Positive control (PCx), ntATX-D1 immunization (D1) and ntATX-D2 immunization (D2) groups received C . septicum challenge. Turkeys were immunized subcutaneously with 100 μg of protein at 7, 8 and 9 weeks of age along with an oil-in-water nano-emulsion adjuvant, followed by C . septicum challenge at 11 weeks of age. Results showed that while 46.2% of birds in the PCx group died post-challenge, the rate of mortality in D1- or D2-immunization groups was 13.3%. The gross and histopathological lesions in the skin, muscle and spleen showed that the disease severity was highest in PCx group, while the D2-immunized birds had significantly lower lesion scores when compared to PCx. Gene expression analysis revealed that PCx birds had significantly higher expression of pro-inflammatory cytokine genes in the skin, muscle and spleen than the NCx group, while the D2 group had significantly lower expression of these genes compared to PCx. Peripheral blood cellular analysis showed increased frequencies of activated CD4+ and/or CD8+ cells in the D1 and D2-immunized groups. Additionally, the immunized turkeys developed antigen-specific serum IgY antibodies. Collectively, these findings indicate that ntATX proteins, specifically the ntATX-D2 can be a promising vaccine candidate for protecting turkeys against CD and that the protection mechanisms may include downregulation of C . septicum -induced inflammation and increased CD4+ and CD8+ cellular activation.

  PublisherDOI

Frequent coauthors

• H. L. Shivaprasad

  University of California, Davis

  68 shared

• L.M. Badcoe

  Washington State Department of Agriculture

  26 shared

• Mary Lea Killian

  United States Department of Agriculture

  25 shared

• Janice C. Pedersen

  National Animal Disease Center

  25 shared

• Valerie Shearn-Bochsler

  United States Geological Survey

  25 shared

• Thomas J. DeLiberto

  Life Services (United States)

  25 shared

• Paul Kohrs

  Washington State University

  25 shared

• Paul DeBruyn

  25 shared

Education

• Ph.D., Animal Science

  North Carolina State University

  2006

• M.S., Animal Science

  University of California, Davis

  2001

• B.S., Animal Science

  University of California, Davis

  1999

Awards & honors

• Scientist of the Year Award from the Pacific Egg and Poultry…