About

Abigail Armwood is associated with the College of Veterinary Medicine at NC State University, where she is involved in fostering student engagement and supporting the academic and personal development of veterinary students. Her role includes overseeing student experience initiatives, promoting extracurricular activities, and encouraging opportunities such as study abroad programs, research projects, and community involvement. She works closely with students, faculty, and staff to create a welcoming and collaborative campus environment that emphasizes student achievement, well-being, and professional growth. Her contributions help shape the future of veterinary medicine by supporting the next generation of veterinarians through mentorship, program development, and fostering a culture of inclusivity and excellence.

Research topics

• Microbiology
• Biology
• Fishery
• Anatomy
• Genetics
• Pathology
• Zoology

Selected publications

• Use of a three-dimensional-printed spine model for surgical planning in a feline vertebral chondroblastic osteosarcoma

  Journal of Feline Medicine and Surgery Open Reports · 2026-01-01

  articleOpen access

  Case summary: A 2-year-old, male neutered domestic shorthair cat presented with a 1-month history of non-specific pain and inappetence, left-sided Horner syndrome, pelvic limb proprioceptive ataxia, upper motor neuron paraparesis and a plantigrade stance. Advanced imaging revealed a heterogeneous contrast-enhancing extradural mass dorsal to the T1-T2 intervertebral disc space, causing severe left-sided spinal cord compression. Medical image processing software was used to generate a patient-specific three-dimensional spine model based on MRI and CT data. A biomechanical three-dimensional-printed replica of the T1-T3 region allowed preoperative simulation of a left-sided hemilaminectomy and mass removal, confirming contiguity of the lesion with the T1 vertebral body and extension along the vertebral canal to T2-T3. The model aided intraoperative landmark identification and facilitated safe and effective spinal cord decompression. Histopathology from surgical biopsy was most consistent with either chondroblastic osteosarcoma or chondrosarcoma. Postoperative radiation therapy was initiated but discontinued owing to difficulties establishing reliable intravenous access. Progressive neurologic deterioration eventually led to euthanasia. Post-mortem CT and necropsy confirmed a diagnosis of chondroblastic osteosarcoma without evidence of metastatic disease. The cat had a survival time of 356 days after surgery (387 days from initial presentation). Relevance and novel information: This report describes the first known vertebral chondroblastic osteosarcoma in a cat. It highlights the value of biomechanical three-dimensional-printed spine models for preoperative planning in complex vertebral surgery and demonstrates that tumor debulking, even when combined with incomplete radiotherapy, can provide meaningful palliation and prolonged survival. Further studies are needed to define optimal treatment strategies and prognosis for feline vertebral osteosarcoma subtypes.

  PublisherDOI

• Clostridium septicum Alpha Toxin-Based Recombinant Subunit Vaccine Protects Broiler Chickens Against Clostridial Dermatitis

  Avian Diseases · 2026-02-16

  article

  induced CD and that the mechanisms of protection seem to operate through anti-ATX antibodies coupled with modulation of local and systemic inflammatory as well as cellular immune responses.

  PublisherDOI

• Intraspecific Variation of <i>Edwardsiella anguillarum</i> From Non‐Anguillid Fish From Varied Geographic Origins

  Journal of Fish Diseases · 2026-02-04

  article1st authorCorresponding

  ABSTRACT Edwardsiella anguillarum is a gram‐negative bacterium, synonymous with previously described atypical, fish‐pathogenic Edwardsiella tarda . Originally described from eels in 2015, E. anguillarum is an important global fish pathogen, particularly in tilapia. This study describes intraspecific phenotypic and genotypic variability among 17 E. anguillarum isolates from non‐anguillid fish hosts and varied geographic origins. Isolates demonstrated similar biochemical characteristics, with slight variation in motility and hydrogen sulfide production. Genomic relatedness among isolates was analysed with repetitive extragenic palindromic sequence‐based PCR (rep‐PCR) and multilocus sequence analysis (MLSA). Rep‐PCR with the ERIC II primer set revealed two distinct genetic clusters, while amplification strategies utilising the GTG 5 , BOX or ERIC I&amp;II primer sets yielded more uniform profiles. While rep‐PCR deemed the isolates largely clonal, MLSA schemes using reference genes from published Edwardsiella MLSA studies revealed E. anguillarum isolates formed five discrete phylogroups. A unique, ~91.5 kB plasmid was identified in Costa Rican and Colombian isolates, associated with conjugative and transposable elements, plasmid mobilisation, and adhesion; however, no plasmid mediated antibiotic resistance genes were identified. This study provides insight into genetic diversity among E. anguillarum isolates from different hosts and geographic regions, identifying an optimal MLSA scheme from previous reports applicable to E. anguillarum isolates.

  PublisherDOI

• Novel frameshift variant in exon 7 of <i>COL17A1</i> in a domestic shorthair kitten with junctional epidermolysis bullosa

  Journal of Veterinary Diagnostic Investigation · 2026-01-26

  articleOpen access

  Junctional epidermolysis bullosa (JEB) is a congenital blistering skin disorder with clefting within the lamina lucida of the basement membrane zone. We describe the clinical and morphologic features of JEB in a 4-mo-old domestic shorthair kitten and identify the underlying genetic variant. The kitten was presented with blistering lesions affecting friction-prone areas of haired skin, mucocutaneous junctions, and oral mucosa. Histopathology revealed extensive subepidermal cleft formation in affected tissues. Periodic acid–Schiff (PAS) staining showed a thin, PAS-positive line along the dermal side of the cleft, consistent with retention of the lamina densa. Transmission electron microscopy confirmed separation at the level of the lamina lucida with intact basal keratinocytes. Whole genome sequencing identified a homozygous 2-bp deletion in exon 7 of COL17A1 , predicted to result in loss of function and disrupted binding domains. Our findings support a diagnosis of JEB associated with a novel COL17A1 variant.

  PublisherOA PDFDOI

• Optic Chiasm and Bilateral Optic Nerve Oligodendroglioma in A 29‐Month‐Old German Shepherd

  Veterinary Ophthalmology · 2025-08-22

  articleOpen access

  OBJECTIVE: To report the first documented case of high-grade optic chiasm and nerve oligodendroglioma in a young dog and contribute to the comparative study of gliomas in humans and canines. ANIMAL STUDIED: A 29-month-old male intact German Shepherd. PROCEDURES: Over 2 months, the patient underwent repeated physical and ophthalmic examinations, systemic health assessments (complete blood count, serum biochemistry, urinalysis, and infectious disease testing), anesthetized MRI, ultrasound-guided biopsy of the left retrobulbar mass, and necropsy. Histopathologic and immunohistochemical analyses, including OLIG2 and GFAP immunohistochemistry, were performed. RESULTS: MRI evaluation identified a large, lobulated, asymmetric mass with retrobulbar involvement and compression of the optic chiasm and optic nerves. The mass exhibited hyperintense signals on T2-weighted and T2-FLAIR sequences, mixed intensity on T1-weighted imaging, and heterogeneous contrast enhancement, with areas of necrosis and meningeal enhancement suggestive of an aggressive neoplasm. Gross necropsy findings and histopathologic examination of post-mortem tissues confirmed the diagnosis of a high-grade oligodendroglioma, with tumor cells demonstrating marked nuclear atypia, high mitotic activity, and OLIG2 nuclear immunoreactivity. CONCLUSIONS: The tumor's localization and histological characteristics suggested a primary origin within the optic pathway, differing from typical canine oligodendrogliomas. This case emphasizes the rarity of canine optic pathway oligodendrogliomas, a diagnosis that is similarly uncommon in human medicine. Dogs have been proposed as an intermediate animal model for human gliomas, and this case underscores the need for further molecular characterization of canine gliomas to improve diagnostic accuracy, therapeutic strategies, and comparative oncology insights.

  PublisherOA PDFDOI

• Recombinant Lactococcus lactis-based oral vaccine expressing non-toxic alpha toxin domains of Clostridium septicum can offer protection against Clostridial dermatitis in turkeys

  Vaccine · 2025-10-01

  articleOpen access

  Clostridial dermatitis (CD), caused by the anaerobic spore-forming Clostridium septicum bacteria, is an important emerging disease of turkeys. Despite its economic burden on the poultry industry, there are no efficacious vaccines currently available for CD control in turkeys. We recently identified two non-toxic domains of C. septicum alpha toxin (ntATX), namely ntATX-D1 and ntATX-D2, and showed that subcutaneous immunization of turkeys with purified recombinant subunit ntATX proteins can offer protection against CD. In the present study, we used the pNZ8124-NICE vector®-based Lactococcus lactis (Str. NZ9000) cloning system to express ntATX-D1 and ntATX-D2 proteins, and immunized turkeys orally at 7, 8 and 9 weeks of age followed by a virulent C. septicum challenge at one-week post-last immunization. Results showed that while both ntATX-D1 and ntATX-D2 vectored-L. lactis vaccines could effectively prevent mortality, the ntATX-D2 carrying vaccine conferred significantly stronger protective immunity, as determined by the gross and histopathological evaluations. Additionally, the immunized birds were found to have antigen-specific serum IgY antibodies. Furthermore, the L. lactis-ntATX-D2 vaccinated turkeys had significantly reduced expression of pro-inflammatory cytokine (Interleukin-1β, IL-6 or Interferon-γ) genes in the skin, muscle, spleen and cecal tonsil tissues when compared to unvaccinated and C. septicum-challenged control group. Our findings show that a L. lactis-based oral recombinant vaccine expressing ntATX-D2 of C. septicum alpha-toxin can provide protective immunity against CD in turkeys, and thus providing a novel scope for devising probiotic-based oral vaccines against important Clostridial diseases in poultry.

  PublisherDOI

• Concurrent <i>Streptococcus equi</i> subsp. <i>equi</i> infection, purpura haemorrhagica and immune‐mediated myositis in a Quarter Horse filly

  Equine Veterinary Education · 2024-02-18 · 2 citations

  articleOpen access

  Summary This report describes a 2‐year‐old Quarter Horse filly that was diagnosed with concurrent Streptococcus equi subsp. equi infection, purpura haemorrhagica, and immune‐mediated myositis. The filly was presented for evaluation of fever of unknown origin, rapid weight loss and inappetence after exposure to strangles that was initially unknown. Over the course of hospitalisation the filly developed mandibular lymphadenopathy, guttural pouch empyema, and mucosal petechiation and ecchymoses. The presence of Streptococcus equi subsp. equi was confirmed via PCR and culture of a lymph node aspirate and biopsies of the skin confirmed leukocytoclastic vasculitis, consistent with purpura haemorrhagica. Genetic testing confirmed that the filly had one copy of the MYH1 mutation (N/My). Following therapy with systemic corticosteroids, plasma transfusion and antimicrobial therapy the filly improved and was discharged. Communication with the owner 11 months later confirmed that filly appeared healthy but remained poorly muscled. This report is the first to the authors' knowledge describing concurrent Streptococcus equi subsp. equi infection, purpura haemorrhagica, and immune‐mediated myositis.

  PublisherOA PDFDOI

• Investigating the etiology of ocular changes in Monodactylus argenteus housed in a shoaling ring exhibit

  Journal of the American Veterinary Medical Association · 2024-08-16 · 1 citations

  articleOpen access

  OBJECTIVE: To evaluate the pathologic ocular changes in a population of aquarium-housed Monodactylus argenteus and investigate potential underlying causes for the large number of affected fish in this exhibit. ANIMALS: 11 Monodactylus argenteus were evaluated from a shoaling ring exhibit within an aquarium, and 19 control fish without ocular abnormalities were obtained from commercial fish suppliers. METHODS: Physical and ocular examinations were performed antemortem. Postmortem samples of liver, heart, dorsal epaxial muscle, and lenses of affected and control fish were analyzed for amino acid profiles. The aqueous humor from affected and control fish was collected postmortem, and osmolality was analyzed. Tissues from affected and control fish were submitted for histopathology. RESULTS: Ocular abnormalities in affected fish included corneal lesions, cataracts, lens capsule rupture, and unilateral left-sided lens luxation and buphthalmos. Lens luxation and buphthalmos were directly correlated. Aqueous humor osmolality in control fish differed significantly compared to affected fish but was not correlated to lens abnormality score. Affected fish had significantly lower lens concentrations of arginine, asparagine, glycine, isoleucine, serine, and tyrosine than control fish. One affected fish had severe buphthalmos, cataracts, and panophthalmitis caused by gram-positive cocci. CONCLUSIONS: Cataracts and traumatic lesions were common in affected M argenteus. Dietary amino acid content and aqueous humor osmolality imbalances were not likely a cause of the cataracts. Differences in lens amino acid concentrations between affected and control fish may be related to cataract formation. CLINICAL RELEVANCE: Consideration of species-appropriate tank parameters may mitigate ocular lesions including cataracts in aquarium fish.

  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

• Liver Nodule from a Bearded Dragon (Pogona Vitticeps)

  SSRN Electronic Journal · 2023-01-01

  preprintOpen access
  PublisherDOI

Frequent coauthors

• Matt J. Griffin

  AstraZeneca (United States)

  7 shared

• Alvin C. Camus

  7 shared

• David J. Wise

  Mississippi Delta Community College

  4 shared

• Bradley M. Richardson

  United States Department of Agriculture

  4 shared

• Cynthia Ware

  Mississippi State University

  4 shared

• Geoffrey C. Waldbieser

  3 shared

• Adrián López‐Porras

  Delta Air Lines (United States)

  3 shared

• Elizabeth W. Howerth

  University of Georgia

  3 shared

Awards & honors

• American Board of Veterinary Practitioners in Fish Practice…
• American College of Veterinary Pathologists Diplomate (2020)