March 2018

SIGNALMENT (JPC 2131320):  White-tailed prairie dog (Cynomys leucurus)

HISTORY:  Tissue from an adult female white-tailed prairie dog (Cynomys leucurus) experimentally infected with an organism isolated from free ranging animals.

HISTOPATHOLOGIC DESCRIPTION:  1. Lymph node and perinodal adipose tissue:  There is an overall loss of lymphocytes and diffusely, normal lymph node architecture (including capsule, cortex, paracortex, and medulla) is lost and replaced by necrotic debris, edema, fibrin, minimal hemorrhage, numerous degenerate and viable neutrophils, and fewer macrophages.  There are numerous perivascular and, to a lesser extent, intravascular large colonies of pale basophilic to amphophilic, 1 x 2 um coccobacilli.  Multifocally, peri and intranodal vessels are characterized by discontinuous endothelium, expansion of the tunica media by fibrin, hemorrhage, edema, neutrophils and fewer macrophages and edema in the tunica adventitia (fibrinoid vasculitis).  Multifocally and predominantly perivascularly, the previously mentioned inflammatory cells, fibrin, edema, necrotic debris, and bacterial colonies extend into and replace perinodal adipose tissue.

  1. Lung: There is diffuse fibrinoid vasculitis characterized by disruption and expansion of the tunica media by fibrin, hemorrhage, edema, neutrophils, and fewer macrophages, often associated with and intraluminal thrombi and occasionally containing large colonies of previously described coccobacilli.  The perivascular connective tissue is expanded by fibrin, hemorrhage, and edema.  Diffusely, alveolar septa are congested and minimally to moderately expanded up to 35um by hemorrhage, fibrin, edema, thrombosed capillaries,  neutrophils and lymphocytes admixed with small amounts of eosinophilic cellular and karyorrhectic debris (necrosis).  Alveolar lumina occasionally contain fibrin, edema, and few alveolar macrophages.  Multifocally, bronchioles contain small amounts of sloughed respiratory epithelium, debris and erythrocytes.

MORPHOLOGIC DIAGNOSIS:  1.  Lymph node:  Lymphadenitis, necrosuppurative, diffuse, severe, with vasculitis, multifocal perinodal steatitis, and numerous intra and extravascular coccobacilli, white-tailed prairie dog (Cynomys leucurus), rodent.

  1. Lung: Vasculitis, fibrinoid, subacute, diffuse, marked, with necrotizing neutrophilic interstitial pneumonia, fibrin thrombi, and numerous intravascular coccobacilli.

ETIOLOGIC DIAGNOSIS:  Yersinial lymphadenitis and pneumonia

CAUSE:  Yersinia pestis

CONDITION:  Plague, Sylvatic Plague, Yersiniosis




  1. Bubonic plague – Swollen, painful, draining lymph nodes, fever, anorexia, dehydration; possible septicemia
  1. Pneumonic plague – Results from hematogenous or lymphogenous spread of organisms as a sequela to bubonic or septic plague
    • Primary pneumonic plague is contracted via inhalation
  1. Septicemic plague – Bacteremia without palpable lymphadenopathy; systemic signs of fever, endotoxic shock and DIC








  1. pseudotuberculosis, Y. enterocolitica (see D-B11)


 Barthold SW, Griffey SM, Percy DH. Pathology of Laboratory Rodents and Rabbits. 4th ed. Ames, IA: Blackwell Publishing; 2016: 186, 230-231, 288.

  1. Brown DL, Van Wettere AJ, Cullen JM. Hepatobiliary system and exocrine pancreas.  In: Zachary JF, ed. Pathological Basis of Veterinary Disease. 6th ed. Philadelphia, PA: Mosby Elsevier Inc.; 2017:444.
  2. Gelburg HB. Alimentary system and the peritoneum, omentum, mesentery, and peritoneal cavity.  In: Zachary JF, ed. Pathological Basis of Veterinary Disease. 6th ed. Philadelphia, PA: Mosby Elsevier Inc.; 2017:380.
  3. Giles C, Boerlin P. Horizontally transferred genetic elements and their role in pathogenesis of bacterial disease.  Vet Pathol. 2014: 51(2);328-340.
  4. Moxley R. Enterobacteriaceae: Yersinia.  In: McVey DS, Kennedy M, Chengappa MM, eds.  Veterinary Microbiology.  3rd ed. Ames, IA: Wiley & Sons, Inc.; 2013:85-94.
  5. Nakamura S, Hayashidani H, Okabe N, Une Y. Aberrant forms of Yersinia pseudotuberculosis as spheroplasts and filaments in yersiniosis in squirrel monkeys.  Vet Pathol. 2015;52(2):393-396.
  6. Simmons J, Gibson S. Bacterial and mycotic diseases of nonhuman primates.  In: Abee CR, Mansfield K, Tardiff S, Morris T, eds.  Nonhuman Primates in Biomedical Research: Diseases, Vol. 2.  2nd ed.  Waltham, MA: Academic Press; 2012:138-141.
  7. Swennes AG, Fox JG. Bacterial and mycoplasmal diseases.  In:  Fox JG, Marini RP.  Biology and Diseases of the Ferret.  3rd ed.  Ames, IA: Wiley & Sons, Inc.; 2014:543-544.
  8. Valli VEO, Kiupel M, Bienzle D. Hematopoietic system. In: Maxie MG, ed. Jubb, Kennedy and Palmer’s Pathology of Domestic Animals. Vol 3. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:209-210.
  9. Yarto-Jaramillo, E.   In: Miller RE, Fowler ME.  Fowler’s Zoo and Wild Animal Medicine.  Vol. 8.  St. Louis, MO: Elsevier Saunders; 2015:403

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