JPC SYSTEMIC PATHOLOGY
REPRODUCTIVE SYSTEM
JANUARY 2019
R-B08

Signalment (JPC #2015774):  A cross-bred ewe

HISTORY:  A flock of cross-bred ewes experienced an abortion outbreak with 40% of the ewes affected.  The aborted fetuses were near-term and in a fresh state. 

HISTOPATHOLOGIC DESCRIPTION:  Chorioallantois: There is diffuse loss of chorionic villar architecture with replacement by abundant eosinophilic cellular and karyorrhectic debris (necrosis), hemorrhage and viable and degenerate neutrophils with fewer macrophages and concretions of intensely basophilic granular material (mineral), which expands the intervillous space.  Still attached and sloughed trophoblasts, scattered throughout the necrotic debris  are often markedly expanded by numerous indistinct intracytoplasmic, amphophilic, 1 um diameter cocci admixed with small amounts mineral. Multifocally within the chorioallantoic connective tissue, blood vessel walls are infiltrated by eosinophilic karyorrhectic debris, neutrophils and scant amounts of fibrin which expand the tunica intima and media (necrotizing vasculitis).  Vascular lumens are multifocally variably occluded by fibrin thrombi.  There are perivascular accumulations of viable and degenerate neutrophils with fewer macrophages, lymphocytes and plasma cells.   Within the chorioallantoic stroma there are low numbers of previously described inflammatory cells as well as increased clear space and dilated lymphatics (edema). The intercotyledonary chorion is ulcerated or lined by epithelium that is degenerate or necrotic, with epithelial cells occasionally containing amphophilic, 1 um diameter cocci.  The surface and underling stroma contain variable amounts of necrotic debris and mineral admixed with neutrophils, lymphocytes and plasma cells.

MORPHOLOGIC DIAGNOSIS:  Chorioallantois:  Placentitis, necrosuppurative, diffuse, severe, with vasculitis, and intratrophoblastic cocci, consistent with Chlamydia abortus, cross-bred sheep, ovine.

ETIOLOGIC DIAGNOSIS:  Placental chlamydophilosis

CAUSE:  Chlamydophila abortus

CONDITION:  Ovine enzootic abortion or Enzootic abortion of ewes (EAE)

GENERAL DISCUSSION:

PATHOGENESIS:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS:

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ULTRASTRUCTURAL FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS:

DIFFERENTIAL DIAGNOSIS:

COMPARATIVE PATHOLOGY:

REFERENCES:

  1. Borel N, Polkinghorne A, Pospischil A. A review on Chlamydial diseases in animals: still a challenge for Pathologists?. Vet Pathol. 2018; 55(3):374-390.
  2. Buxton D, Anderson IE, Longbottom D, Livingston M, Wattegedera S, Entrican G. Ovine chlamydial abortion: characterization of the inflammatory immune response in placental tissues. J Comp Pathol 2002;127:133-141.
  3. Giannitti F, Anderson M, Miller M, et al. Chlamydia pecorum: fetal and placental lesions in sporadic caprine abortion. J Vet Diagn Invest. 2016; 28(2): 184-9.
  4. Gutierrez J, O’Donovan J, Proctor A, et al. Application of quantitative real-time polymerase chain reaction for the diagnosis of toxoplasmosis and enzootic abortion of ewes. J Vet Diag Invest. 2012;24(5):846-854.
  5. Hazlett MJ, McDowall R, DeLay J, et al. A prospective study of sheep and goat abortion using real-time polymerase chain reaction and cut point estimation shows Coxiella burnetiiand Chlamydophila abortus infection concurrently with other major pathogens. J Vet Diag Invest. 2013;25(3):359-368.
  6. Longbottom D, Livingstone M, Maley S, van der Zon A, Rocchi M. Intranasal infection with Chlamydia abortus induces dose-dependent latency and abortion in sheep. PLoS ONE. 2013; 8(2) e57950.
  7. Lopez A, Martinson SA. Respiratory system, mediastinum, and pleurae. In: McGavin MD, Zachary JF, eds. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:552.
  8. Martinez CM, Buendia AJ, Sanchez J, Ortega N, Caro MR, Gallego MC, Navarro JA, Cuello F, Salinas J. Relative importance of CD4+ and CD8+ T cells in the resolution of Chlamydophila abortus primary infection in mice. J Comp Pathol. 2006;134:297-307.
  9. Masala G, Porcu R, Daga C, Denti S. Detection of pathogens in ovine and caprine samples from Sardinia, Italy, by PCR. J Vet Diagn Invest. 2007;19:96-98.
  10. Navarro JA, Ortega N, Buendia AJ, Gallego MC, Martínez CM, et al. Diagnosis of placental pathogens in small ruminants by immunohistochemistry and PCR on paraffin-embedded samples. Vet Rec. 2009;165:175-178.
  11. Sammin DJ, Markey BK, Quinn PJ, McElroy MC, Bassett HF. Comparison of fetal and maternal inflammatory responses in the ovine placenta after experimental infection with Chlamydophila abortus. J Comp Pathol. 2006;135:83-92.
  12. Schlafer DH, Foster RA. The female genital system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 3. 6th ed. St Louis, MO; 2016:415-416.


Click the slide to view.



Click on image for diagnostic series.



Back | Home | Contact Us | Links | Help |