Alexandra Armstrong, DVM, DACVP, PhD

Assistant Professor, Pathology, Veterinary Clinical Sciences
Alex Armstrong smiling sitting at a microscope


Office Phone
Office Address

E300 Veterinary Science Building
1971 Commonwealth Avenue
St. Paul, MN 55108
United States


PhD, University of Minnesota

Veterinary Anatomic Pathology Resident, University of Minnesota

DVM, University of Minnesota


Comparative Pathology Fellowship, Johns Hopkins University

Licensures and Certifications

Diplomate American College of Veterinary Pathology


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Dr. Armstrong is a veterinary anatomic pathologist with a passion for translational research using animal models to understand human and veterinary diseases. She is particularly interested in developmental orthopaedic diseases and better understanding their pathogenesis and improving our methods for determining prognosis and treating disease. She loves research and also enjoys teaching veterinary students and residents and occasional diagnostic pathology work.  


Her PhD work focused on the validation and evaluation of animal models of human diseases, including murine models of osteoarthritis, piglet models of osteochondrosis, and piglet models of Legg-Calvé-Perthes disease (LCPD). She's particularly passionate about developmental orthopaedic diseases and is currently investigating the molecular mechanisms involved in growth cartilage injury and repair in a piglet model of LCPD. LCPD is characterized by loss of blood flow to the femoral head, causing collapse of the femoral head over time and osteoarthritis if not corrected. She uses microscopic images to understand what is happening in the tissue on a cellular level and correlate this with noninvasive imaging findings to better understand and monitor this disease. 

Awards and Recognition

2022     Fang Li Research Award in Clinical Veterinary Science

2021    Society of Toxicologic Pathology Daniel Morton and Laura Dill Morton Scholarship 

2020    College of Veterinary Medicine Research Day Infographic Winner 


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Funded Grants

K01 OD034070                       Armstrong (PI)                                                9/1/2023-8/31/2028

Spatialomics and quantitative MRI of ischemic injury in a piglet model of Legg-Calve-Perthes disease

The major goal of this project is to develop as an independent investigator with expertise in spatialomics and quantitative MRI for investigation of the pathophysiology of pediatric developmental diseases using animal models of disease.

Role: PI

Key Publications and Book Chapters

Key Publications

  1. Armstrong AR, Tóth F, Carlson CS, Kim HKW, Johnson CP. Effects of acute femoral head ischemia on the growth plate and metaphysis in a piglet model of Legg-Calvé-Perthes disease. Osteoarthritis and Cartilage. In press, accepted 1/17/23.   doi: 10.1016/j.joca.2023.01.011 
  2. Armstrong AR, Zbyn S, Kajabi AW, Metzger GJ, Ellermann JM, Carlson CS, Tóth F. Naturally occurring osteochondrosis latens lesions identified by quantitative and morphological 10.5T MRI in pigs. Journal of Orthopaedic Research. 2023;41(3):663-673.  DOI: 10.1002/jor.25401    
  3. Armstrong AR, Bhave S, Buko EO, Chase KL, Tóth F, Carlson CS, Ellermann JM, Kim HKW, Johnson CP. Quantitative T2 and T1ρ mapping are sensitive to ischemic injury to the epiphyseal cartilage in an in vivo piglet model of Legg-Calvé-Perthes disease. Osteoarthritis and Cartilage. 2022;30(9):1244-1253. DOI: 10.1016/j.joca.2022.05.009  
  4. Strzok E, Torres S, Moore M, Armstrong AR. A case of acute eosinophilic dermatitis and edema. Journal of American Veterinary Medical Association. 2022;259(S2):1-4. DOI: 10.2460/javma.21.01.0046  
  5. Loeser RF, Coryell PR, Armstrong AR, Collins JA, Prasai P, McDermott KA, Ran Q, Carlson CS. Overexpression of peroxiredoxin 3 in cartilage reduces the severity of age-related osteoarthritis but not surgically-induced osteoarthritis in mice. ACR Open Rheumatology. 2022; 4(5):441-446. DOI: 10.1002/acr2.11420  
  6. Armstrong AR, Carlson CS, Rendahl AK, Loeser RF. Optimization of histologic grading schemes in spontaneous and surgically-induced murine models of osteoarthritis. Osteoarthritis and Cartilage. 2021;29(4):536-546. DOI: 10.1016/j.joca.2021.01.006  
  7. Johnson CP, Tóth F, Carlson CS, Armstrong AR, Zbyn S, Wu B, Ellermann JM, Kim HKW. T1ρ and T2 Mapping Detect Acute Ischemic Injury in a Piglet Model of Legg-Calvé-Perthes Disease. Journal of Orthopaedic Research. 2021;1-11. DOI: 10.1002/jor.25044 
  8. Tan L, Harper LR, Armstrong AR, Carlson CS, Yammani RR. Dietary saturated fatty acid palmitate promotes cartilage lesions and activates the unfolded protein response pathway in mouse knee joints. PLOS One. 2021:16(2):1-13DOI: 10.1371/journal.pone.0247237 
  9. Marston S, Mirick G, Sabin A, Hansen G, Lindgren B, Aparicio C, Armstrong AR, Larsen OH, Schmidt A, Kyle R, Gustilo R, Tsukayama D, Bechtold J, Bue M. Systemic versus Free Antibiotic Delivery in Preventing Implant Related Infection in a Rat Model. Journal of Orthopaedic Research. Accepted March 2021 for special issue. 429-438. DOI:10.1002/jor.25052  
  10. Chau M, Toth F, Bendre A, Armstrong AR, Macalena J, Tompkins M, Clohisy D, Nilsson O, Carlson CS. Microenvironmental influences on articular chondrocyte differentiation. Orthopaedic Journal of Sports Medicine. 2020;8(4; S3). DOI:10.1177/2325967120S00231 
  11. Shea MK, Booth SL, Harshman SG, Smith D, Carlson CS, Harper L, Armstrong AR, Fang M, Cancela ML, Simão M, Loeser RF. The effect of vitamin K insufficiency on histological and structural properties of knee joints in aging mice. Osteoarthritis and Cartilage Open. 2020;2(3):.  DOI: 10.1016/j.ocarto.2020.100078   
  12. Loeser RF, Kelley KL, Armstrong AR, Collins JA, Harper L, Diekman BO, Carlson CS. Deletion of c-Jun N-terminal kinase enhances senescence in joint tissues and increases the severity of age-related osteoarthritis in mice. Arthritis & Rheumatology. 2020; 72(10):1679-1688 DOI:10.1002/art.41312   
  13. Armstrong AR, Wünschmann A, Klein EC, Rigatti LH. Brief Communication: Clostridium difficile enterocolitis in a captive Geoffroy’s spider monkey (Ateles geoffroyi) and common marmosets (Callithrix jacchus). Veterinary Pathology. 2019; 56(6):959-963.  DOI: 10.1177/0300985819864307

Book Chapters

Olson EO, Dykstra J, Armstrong AR, and Carlson CS. (2022). Chapter 16: Bone, Joints, Tendons, and Ligaments. In Zachary JF, McGavin MD (Ed). Pathologic Basis of Veterinary Disease. 7th edition. Published January 2022.     


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Anatomic Pathology

Clinical Interests

Translational Animal Models


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Academic Interests and Focus

She enjoys teaching systemic pathology and creating hands-on opportunities for pathology learning for the DVM students and anatomic pathology residents. 

Teaching Areas

She teaches gastrointestinal, hepatic, nervous system, and muscular pathology in the 2nd year DVM systemic pathology course.